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pangea
02-19-2004, 08:36 AM
Hi!

I don't know if this is interesting or not, but I found this ad at parts express, if anyone is looking for a JBL sub.

JBL SUB1500 15" SUBWOOFER 4 OHM
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-750&orefer=esf021904-299-750

BR
Roland

JuniorJBL
02-19-2004, 09:39 AM
Looks like the car version of the 2226G

Alex Lancaster
02-19-2004, 10:30 AM
It is interesting, anybody know more?

Alex.

Mr. Widget
02-19-2004, 10:44 AM
I haven't loaded BBPro on my new computer yet, but I would love to check it out. That looks like quite a sub.

TimG
02-19-2004, 12:15 PM
Dude, that isn't a car sub, that is the 15" driver from the Revel Ultima 15 sub, made by JBL for their Harmon parent company. It looks like a modified 2227 motor, but it has more xmax than any current JBL 15. It would make a great sealed box sub with some equilization.

Mr. Widget
02-19-2004, 12:52 PM
Tim,

Are you sure that is the Revel Ultima sub? I've heard them and they are phenomenal.

Widget

JuniorJBL
02-19-2004, 01:20 PM
http://www.audioclub.it/audio/prodotti/REVEL/revelsub15le1.htm
It does look like the 2227.
Very cool!:D

JuniorJBL
02-19-2004, 01:24 PM
I would really like to see the new JBL 15" and 18" 2256 and 2258
woofers from the Vertec series!
:thmbsup:

mikebake
02-19-2004, 02:05 PM
Hmmmmm, I'm almost buying the sales pitch, as in "buy now as they are the last of them".........whaddaya guys think about this driver???
Widget??
Subwoof??
Giskard??
et al???

Mr. Widget
02-19-2004, 03:58 PM
Just installed BBPro and ran the numbers.:cool: No wonder those Revel subs sounded so good. The group delay is not as good as the 2235H or 2245H so it will not have quite the transient response, but boy does it have LF extension!

I am very tempted.....:hmm:

One of the cool things about them is that they will go deep in a fairly small enclosure. I just called and they have 400 left. Sorry guys I may just take all of them.:D

Guido
02-19-2004, 04:08 PM
I'm jealous!

This is less than 200 Euros and It is sold only in the states :banghead:

TimG
02-20-2004, 05:21 AM
Here is what it looks like in a 4 cu ft vented box tuned to 25Hz. Please don't buy them all, I need to pick up some overtime.

4313B
02-20-2004, 06:35 AM
Originally posted by mikebake
Hmmmmm, I'm almost buying the sales pitch, as in "buy now as they are the last of them".........whaddaya guys think about this driver???
Widget??
Subwoof??
Giskard??
et al??? It's a very nice VLF transducer Mike. Loads of moving mass, something JBL has seemed to have moved away from these days. I question an SPL rating of 94 dB. I guess it's worth my while to try and get more info on it.

JuniorJBL
02-20-2004, 08:34 AM
Does anyone have an idea as to how these would compare to say a 2242 or 2226? Would the 2242 be more musical than a woofer that has such a low Fs?
:confused:

Don McRitchie
02-20-2004, 08:47 AM
The driver in question is definitely the original Revel Ultima Sub. I remember the detailed photos of it that used to be on Revel's website. It was pretty much a JBLPro design. I believe that Doug Button was responsible for it.

Regarding the question on the 2256 sub used in the Vertec, I believe this is the 15" JBL GTI sub (i.e. car sub) with a different cone assembly. I saw a bunch of them sitting on a pallet during my last visit to the Northridge plant. I just assumed they were the GTI subs, since they looked identical. However, on closer inspection, there was a "2256" foilcal on the frame.

JuniorJBL
02-20-2004, 09:31 AM
What is your opinion (or anyone elses)of the 2256/GTI 15"/revel sub for home use versus an 18" 2242 or 2? I have 1 2242 with one on the way. but the space savings would be nice.
:confused:

johnaec
02-20-2004, 11:06 AM
Regarding the question on the 2256 sub used in the Vertec, I believe this is the 15" JBL GTI sub (i.e. car sub) with a different cone assembly.Does that mean the 2256 has the 3" V.C. vs. the 4" in the 1500? Interesting that the 15" GTI actually has a greater Xmax spec'd than this 1500.

JuniorJBL
02-20-2004, 11:12 AM
Originally posted by johnaec
Does that mean the 2256 has the 3" V.C. vs. the 4" in the 1500? Interesting that the 15" GTI actually has a greater Xmax spec'd than this 1500.

Looks to be true

http://www.jblpro.com/vertec1/new_vertec/pdf/VT4881.pdf
:D

Mr. Widget
02-20-2004, 11:28 AM
These three woofers are all quite different. The Vertec 2256 has dual tandem 3" coils. The GTI probably has higher distortion and sacrificed transient response since it is designed to make the rear window of a car rattle.

As for a comparison between the 2242 and the JBL/Revel woofer, the JBL/Revel has as good or better VLF performance in a 3-4 cu ft box as the 2242 has in an 8-10 cu ft box. Above 45Hz the 2242 can put out a bit more output, but the JBL/Revel is capable of 119dB from about 25Hz up. In a home, do you need more? You will need a lot of horsepower to do this, but it can do it.

I have heard these woofers in their Revel enclosures a couple of times. I was very impressed. To be fair to Revel part of their $4000 price was due to the very sophisticated electronics that came with them.

JuniorJBL
02-20-2004, 11:37 AM
I have a crown K2 500wpc 8ohms 800wpc 4ohms 1250wpc 2ohms
I would think this is adequate:D

4313B
02-20-2004, 11:38 AM
"In a home, do you need more?"

Evidently so! :p

Some guys are running dual 2234H's or 2235H's per side, some are running a 2242H or 2245H per side and a few are running dual 2242H's or 2245H's per side! :p

JuniorJBL
02-20-2004, 11:46 AM
Originally posted by Giskard
"In a home, do you need more?"

Evidently so!

I would think a 15" driver might be a little faster than an 18" driver.
For jazz this might be a good thing. But an 18" would probably be better for rock and roll.

How about a PROFESIONAL opinion!!
We do have those here, right?
:shock: :spin: :yes:

4313B
02-20-2004, 12:00 PM
Originally posted by JuniorJBL
I would think a 15" driver might be a little faster than an 18" driver.Um, that would be a no. That SUB1500 appears to be dragging around a lot of weight with a less powerful motor than either the 2242H OR 2245H. I think the SUB1500 has +200 grams of moving mass doesn't it? That's roughly like sticking a 121A/121H mass ring into a 2235H.

johnaec
02-20-2004, 12:19 PM
So how do you think that 1500 would compare with a 2245H?

John

4313B
02-20-2004, 12:30 PM
I'm a big believer in A/B tests. I'd definitely like to get a pair of these SUB1500's for trials.

johnaec
02-20-2004, 12:35 PM
Well, I went ahead and ordered one. 'Guess I'll be able to do some A/B tests with the 2245 before long...

4313B
02-20-2004, 12:41 PM
Just one??? Hmmm... I thought running just one sub went out with the end of the Seventies... ;)

Mr. Widget
02-20-2004, 01:21 PM
Originally posted by Giskard
I'm a big believer in A/B tests. I'd definitely like to get a pair of these SUB1500's for trials.

Agreed!

I have a pair of 2245s waiting for cabinets. On paper the SUB1500 will put out a bit more VLF bass than even the 2245. I have a pair of 4 cu ft boxes that could happily accomodate them, but I would want to compare them to the 2245s. As for dual 2235s per side, I have that now and have exceeded their xmax on several movie sound tracks. The great thing about the 2235 is that they sound good well above sub woofer applications. The SUB1500 with all of that moving mass was truely designed for subwoofer applications.

johnaec
02-20-2004, 01:28 PM
Originally posted by Giskard
Just one??? Hmmm... I thought running just one sub went out with the end of the Seventies... ;) Well, this is for my never-ending quest for the stongest 40hz for bass guitar I can get out of 6 cu.ft. or less cabinet. The 1500 may even allow me to get something significant below that with a subharmonic synthesizer I've got...what the heck...

4313B
02-20-2004, 05:15 PM
"Well, this is for my never-ending quest for the stongest 40hz for bass guitar I can get out of 6 cu.ft. or less cabinet."

Ah!

Here are some additional numbers to play with.

Mr. Widget
02-20-2004, 05:44 PM
How do I explain another pair of woofers to the wife!:banghead:

johnaec
02-20-2004, 06:14 PM
By my calcs, 47.2 liters = 1.67 cu.ft. - wow! I guess I need to start plugging some numbers into my speaker program.

Mr. Widget
02-20-2004, 08:38 PM
Yeah, I did those calculations myself. Too bad I bought all 400 of them.:D I guess we can negotiate a price on a couple.;)

Seriously, I think I will go the vented route. 4 cu ft with no EQ. But I suppose one can always play with an EQ and a sealed box later. My calc showed a 1.6 cu ft box will require a fair amount of EQ.

Race you to the phone in the morning. They're open at 9:00 AM ET.

johnaec
02-20-2004, 10:30 PM
Seriously, I think I will go the vented route. 4 cu ft with no EQ.Yeah, I think so too. That will still leave me room to put a .5 cu.ft. box inside for a 10" mid-bass, (live bass guitar, remember), and still be under my target 6 cu.ft. for mobility.

If I like this new 15", I'll probably sell the 18" 2245 to get a second one, if they're not sold out by then...that way I can have 2 nice subs for the stereo if the band goes bust...:hmm:

4313B
02-21-2004, 05:17 AM
"I think I will go the vented route. 4 cu ft with no EQ."

I would try 4.0 to 5.0 cubic feet sealed first. It will go almost as low as the old B212 (121A/121H in 2.0 cu. ft. sealed volume with no EQ) in that sized volume without EQ. You might prefer the improved transient response of the sealed enclosure. The driver is designed specifically for use as a sub in small sealed volumes.

"My calc showed a 1.6 cu ft box will require a fair amount of EQ."

True, that's what it was originally designed for. The designer of the REVEL15 driver runs two of them in their original Ultima Gem Sub boxes (1.5 cu. ft. sealed) which is also electronically EQ'd through the Revel amp. In his room response is flat to ~ 15 Hz. The designer recommends running a pair of them in rooms of ~ 3,000 cu. ft.

mikebake
02-21-2004, 06:00 AM
Bakers Mantra;
Fifteen inch drivers are not "faster" than eighteens. "Faster" needs deleted from the audio lexicon. End of rant.

4313B
02-21-2004, 06:55 AM
I expected this (micro?) rant days ago Mike. Been too busy? :p

mikebake
02-21-2004, 07:37 AM
El-Giskardo;
Yeah, busy spending money; ordered two more networks from JBL; since they have provision to bi amp whenever I want, they sorta supplant the need for the others entirely, other than should I wish to tri amp (not particularly likely);
Then I've been promising to set up my nephew with some gear; I was going to have the surrounds refoamed on some Pioneer HPM 40's that the neighbor threw out, but decided to give him my little "wood drum" noRh speakers and a cheapo powered sub I had laying around. This necessitated buying him an AV receiver and a CD player.
Now I'll be trying the 3115's with my HT receiver rig.
Now that the powered subs went to a new home, I had to replace them. They were on my deck, under small grill covers, doing year 'round duty.
Enter E-Tent sale, which I hadn't patronized in awhile. I bought two Control 18S-WH, which includes the optimount hardware. I'll go passive "subs" on the deck now; no 110v juice flowing and much more weather resistant. Probably won't have the grunt that the powered subs did, but I've got plenty of power for them, and, well, we'll see. The response graph indicates they are more like a modest woofer, but that's okay, that's what I need under the Control 1AW's, which sound decent outside. Figure that by buying all real weather-resistant gear, I'll have less to worry about. I use the outdoor system 4-5 days a week, year round. It is four speakers and two subs. Kinda fun.
Then, the Pioneer HPM100's come out of the loft and two powered subs and el-cheapo sats go up for living room sound. Rat Shack had a diecast speaker with 5.5 inch Kevlar driver and Linaeum tweeter for $29 on closeout. Less visually obtrusive than two HPM100's looming over the railing.
I SHOULD have two of those SUB1500's sent to you from PE and let you build some 4 footers for them. Save space in the HT.
What kind of power do you project they'd need?

MBB

4313B
02-21-2004, 07:43 AM
"I SHOULD have two of those SUB1500's sent to you from PE and let you build some 4 footers for them. Save space in the HT."

Bring 'em on! :yes:

We can A/B them with the 2245H's :D

"What kind of power do you project they'd need?"

What are you using on the 2245H's?

mikebake
02-21-2004, 08:18 AM
Hmmm, well, right now I am using my noRh LeAmps; 100 watts with a power supply good for a 400 watt amp. I have the pro amps, but don't like the fan noise in the house.

pangea
02-21-2004, 10:13 AM
Originally posted by Mr. Widget
Yeah, I did those calculations myself. Too bad I bought all 400 of them.:D I guess we can negotiate a price on a couple.;)

Seriously, I think I will go the vented route. 4 cu ft with no EQ. But I suppose one can always play with an EQ and a sealed box later. My calc showed a 1.6 cu ft box will require a fair amount of EQ.

Race you to the phone in the morning. They're open at 9:00 AM ET.

Hey, what about me...couldn't you leave one or two to me, huh?

That's typical for damned Yankees... That's what you get for letting someone in on your secrets. :banghead: :biting: :bomb:

BR
Roland

mikebake
02-21-2004, 10:29 AM
Wouldn't have been a secret for long; the day you posted, my PE flyer came and had those on the front. I try not to miss something about JBL.................

Mr. Widget
02-21-2004, 10:38 AM
Hey Roland,

Thanks for the tip. Those are certainly some amazing woofers. I wonder if the Revel Sub 30 is really that much better.

Unfortunately what makes for a fun loudspeaker project doesn't necessarily make for domestic bliss so I will have to sneak these in under the cover of darkness.:yes:

Widget

johnaec
02-21-2004, 01:38 PM
Well, I broke down and ordered a second Sub1500 today, just to be sure I don't end up with a one of a kind...:rolleyes:

I've got a dual-15 baffle available for my current ~7 cu.ft. bass guitar enclosure. I can temporarily drop them into that - 'should be fun...it's where my 2245H is now. I made the cabinet with a removable baffle so I can plug different speakers in for comparison - unfortunately, it's usually "seat of the pants" comparison because of just the one enclosure, though I do have an RTA and other testing equipment here if I decide to get technical.

It'll probably be a while before I can actually build optimized enclosures for these, since I'm hopefully moving into a new home next month, and don't have anywhere to set up a table saw until then. If any of you San Francisco area guys have access to a cabinet shop, feel free to let me know. ;)

4313B
02-21-2004, 01:55 PM
"Well, I broke down and ordered a second Sub1500 today, just to be sure I don't end up with a one of a kind..."

Well, better safe than sorry and it is a fantastic subwoofer driver.

speakerdave
02-22-2004, 12:35 PM
I already have plans to make a subwoofer with the 1400nd I have on hand--I bought these before the LSR 32's with another idea in mind.

I know the 1400nd is not designed for subwoofer use, although I also know some people have done it. (I've read the G. T. suggests using them in pairs--Does he mean two on each side?) It's designed to work up to the mid hundred Hz and is excursion limited. But I thought the fact that the 1400nd has a neodymium magnet like the woofer in the LSR32 would make the two compatible. Besides, I already owned them.

The LSR32 is so good in it's operating range that I did not want to touch it even to the point of putting an active crossover in front of it. I was going to cut the subwoofer in at 50 Hz and let the LSR32 run full range. It is 3 dB down at 53 (absolutely flat to 60). I thought with the 1400nd and the 252G running together below 50 Hz there would be plenty of bass with room rise.

Now this thing comes along. For making a subwoofer to work with a speaker really good to 60 Hz it must be considered, especially since the 1400nd's would pay for the sub1500s and the cabinets and some SACD's.

I need help with the concept of group delay. I take it from reading that the driver parameters, crossover and enclosure are all factors. Mr. Widget, how bad is it? Since the enclosure type is also part of the filter, would group delay be less in a sealed enclosure? Would placement elsewhere in the room, away from the main speakers but closer to the listening position, help or hurt the group delay issue?

Would expert opinion on transient response prefer the 1400nd in 4.1 ft ported enclosure to the sub1500 sealed in the same size box?

There are probably other questions I should ask.

I need help thinking this through.

Thanks,

David

4313B
02-23-2004, 08:50 PM
"Would expert opinion on transient response prefer the 1400nd in 4.1 ft ported enclosure to the sub1500 sealed in the same size box?"

No. A properly designed vented system cannot beat a properly designed sealed system in transient response. Transient response is directly related to frequency response, the shallower the roll-off the better the transient response. One might want to read up on the pros and cons of sealed versus vented systems. Neither is the be-all end-all. This particular driver thrives in the sealed enclosure just like the original 121A/121H did.

I looked at the numbers on this driver again and it will indeed match the old B212 in bandwidth when used in a 4.0 cubic foot sealed enclosure. Very impressive! A slightly smaller package than the old B380. All the bandwidth of the B212 with considerably more thermal and displacement limited power handling capacity and slightly higher sensitivity plus much lower distortion. What a deal!

Anyway, one would do well to try both sealed and vented and choose the one they personally prefer.

speakerdave
02-23-2004, 09:03 PM
OK. Thanks, Giskard.

David

Mr. Widget
02-23-2004, 09:59 PM
"I need help with the concept of group delay. I take it from reading that the driver parameters, crossover and enclosure are all factors. Mr. Widget, how bad is it? Since the enclosure type is also part of the filter, would group delay be less in a sealed enclosure? Would placement elsewhere in the room, away from the main speakers but closer to the listening position, help or hurt the group delay issue?"

Ditto what Giskard said.

I plan to try a pair of them in a pair of 4 cu ft enclosures that I have. I will try them both sealed and ported. The primary benefit of sealed is as Giskard pointed out, better transient response. There are two functional downsides to it's use in a sealed box. First it will require equalization, second it will not produce quite as much output at say 25Hz regardless of amplifier power. Below about 19Hz the sealed box will actually have greater maximum output though. According to BBPro in a 4 cu ft sealed box it will be able to produce a phenomenal 85 dB at 5Hz!!!

Of course the audible differences between ported and sealed are purely subjective. I want to try both to see which I prefer.

Now as far as group delay is concerned, a driver's group delay with a given tuning has no bearing on the system's time alignment. Placing a sub nearer or further from the rest of the system will not be affected by it's group delay. I am not sure of the definitive definition of group delay, but I think of it as how well a driver can pass a pulse or recreate it's portion of a square wave. As the group delay goes up the pulse will get more and more smeared.

I hope this helps.

Widget

speakerdave
02-23-2004, 10:37 PM
Yes it does, and thanks.

For reasons I may not be able to fully articulate, I'm going to go with the 1400nd's for now.

One reason is that I know I would not want to make them go away without having tried them.

I may miss out on the sub1500's, but that's OK. I'm not going to float another pair of woofers right now.

I also think the 1400nd is going to be more to my taste in a woofer. I'm just not interested in sheetrock-loosening bass; I'm not an HT devotee, and I'm only mildly amused by organ pedal notes. I think I can lay enough of a foundation with the 1400nd's and the 252's running in common. I have a feeling that with the sub1500s I would end up crossing the LSR 32's out, and I don't want to do that.

In the long run probably the best subwoofer for the LSR32's is the one in the LSR series that was engineered to work with them.

Finally, I want to hang onto the 1400nd's as the basis of a shot at the M9500 later on.

This has really helped, to be able to kick this around.

Thanks again,

David

4313B
02-24-2004, 07:45 AM
"There are two functional downsides to it's use in a sealed box. First it will require equalization"

If you are going to use it in a 1.5 cubic foot sealed box and if you don't mind the additional group delay the EQ adds. +3 to +6 dB of EQ in the low 20's should do. I would probably port it before adding any EQ to the 4.0 cu. ft. sealed box. In the 4.0 cu. ft. sealed box it will yield pretty much the same bandwidth as the old B212. If anyone doesn't think the old B212 has sufficient bandwidth then they aren't using it right. There were dealers all across the country back in 1977 who didn't have the first clue what to do with a subwoofer back when it first hit the market. Usually subwoofers have their drivers low to the floor so they pickup a bit of boundary reinforcement already. If you go vented, keep the driver up off the floor a bit. Another nice thing about sealed is they tend to drop at roughly the same rate a typical room rises so the net result is quite nice. JBL seems to be trying to accomplish this with their ported Bessel systems these days. Kind of like trying to compromise between the transient response of the sealed and the increased sensitivity of the vented.

Speakerdave - I thought you had a pair of 2242H subs? Those are definitely one better than the REVEL15 if you can afford the real estate for their large enclosure requirements.

JuniorJBL
02-24-2004, 12:50 PM
is every one using the specs from the PE web site or the numbers Giskard posted?
Some of the specs dont look the same. I do not know much about all the T/S parameters but it seems most software uses different T/S to get the same plot.
Could someone possibly guide me in the right direction as to the T/S parameters that are required to get the right responce for a box program? It also seems that some T/S parameters have a different name even though they mean the same thing.
I may not be asking the right questions so please enlighten me.
Shane:)

Chas
02-24-2004, 12:55 PM
Hey, these are too good to pass up. I am going to try a pair in eq'd sealed boxes. It kind of reminds me of a pair of McIntosh ML-1c's I had back in the seventies. Even back then they had fairly impressive LF capabilties for a low effeciency system.

But, they will have to wait, my 4333 system in 4505 (remember, I am the guy stuck with the 4325's?) boxes are nearing completion. Just waiting for the paint to dry...........

BTW Giskard, early measurements of your substitute L300 network are looking pretty good. Once I get all the drivers installed I'll do some more, accurate measurements.
Charles.

4313B
02-24-2004, 01:40 PM
The numbers I posted are from the actual JBL Engineering Design Specification. The numbers PE posted are from running one of the drivers they have in stock through their CLIO system. Vas is easily the most difficult measurement to take so keep that in mind.

One must have a minimum of Qts, Vas, and Fs for most box modelling software. The more info you want out the more info you have to put in.

Don C
02-24-2004, 01:54 PM
I'm wondering how this would work in one of Parts expess's own 3.0cu ft ready made sub boxes.
http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=18478008&St=3528&St2=-77174692&St3=79279707&DS_ID=3&Product_ID=9385&DID=7

johnaec
02-24-2004, 02:00 PM
Quite a bit of difference in the FS and VAS - 'any reliable way to determine which is more accurate?

John

4313B
02-24-2004, 02:07 PM
Ok, I just briefly compared the two sets of TS parameters. My guess would be JBL ran their test after break in :D. The PE driver might not have been sufficiently broken in, if at all. Note that Vas is easily the hardest parameter to measure.

4313B
02-24-2004, 02:14 PM
Originally posted by Don C
I'm wondering how this would work in one of Parts expess's own 3.0cu ft ready made sub boxes.I suppose it could work. The internal standing wave would occur at ~ 380 Hz and it would be greatly amplified since it's a cube but it you crossed over real low it might not suck. :p

mikebake
02-24-2004, 02:20 PM
I'm going to posit that we'll see a number of designs from guys using this driver before long; make sure you guys keep us posted on your results, now ya hear!

JuniorJBL
02-24-2004, 03:19 PM
The subs are on the way!! They should be here on thursday. I am working on designs from about 2-5 cuft. I will probably end up with one at about 2 cuft and one at about 4 cuft. I may cut a vent in the 4 cuft for further testing. Pics and stuff I will be collecting for the forum.
Shane :)

JuniorJBL
02-25-2004, 11:24 AM
Originally posted by Giskard


I looked at the numbers on this driver again and it will indeed match the old B212 in bandwidth when used in a 4.0 cubic foot sealed enclosure. Very impressive! A slightly smaller package than the old B380. All the bandwidth of the B212 with considerably more thermal and displacement limited power handling capacity and slightly higher sensitivity plus much lower distortion. What a deal!



Giskard would you mind posting a screen shot of your graph of SPL/Frequency responce impedance plots?
I would like to compare with speaker workshop. I show a bump of about 3db at 50 Hz and that does not seem right.
Thanks Shane:)

johnaec
02-25-2004, 08:01 PM
I saw this at another site - does it sound accurate?

Measuring Vas (equivalent air compliance)
To measure Vas, use a good solid enclosure of known volume that's about a cube of the nominal speaker size. Determine the total volume, including the speaker cut-out and that trapped by the cone with the speaker mounted on the outside of the box for easy access. Measure the resonant frequency in this situation as well as the free air space resonant frequency.

Vas = Vb((Fb/Fs)^2 - 1)

where

Vb is the volume trapped by the speaker and box
Fb is the resonance frequency of speaker and box

John

4313B
02-26-2004, 11:50 AM
"Giskard would you mind posting a screen shot of your graph of SPL/Frequency responce impedance plots?"

Ok


John,

Looking at the MLSSA page I posted
Fs = 21.47 Hz
Fb = 46.61 Hz
Vb = 47.20 liters

from your formula Vas = Vb((Fb/Fs)^2 - 1), Vas should be 175.25 liters which isn't quite the 181.22 liters JBL calculated.

JuniorJBL
02-26-2004, 06:54 PM
It is in a 2.2 Cu Ft sealed box. 2.5 with bracing and stuff. It sounds GREAT for the amount of space that it takes up. A little EQ at about 30Hz from my rane sp15, crossover ashley 1001 24db per at about 65 Hz. This woofer ROCKS. But you already knew this because it was made by JBL!!!!!!:D :smthsail:

johnaec
02-26-2004, 07:41 PM
'Just got my first one too! Here are some pics comparing the SUB1500 with a soft-dome E140:

http://mark8.org/users/johnaec/1500-1.jpg

Side view comparing depth is below:

http://mark8.org/users/johnaec/1500-2.jpg

In the next pic, notice the three little holes on the top of the magnet. These are vents covered with a very fine cloth mesh from the inside. The standard rubber protector surrounds the magnet:

http://mark8.org/users/johnaec/1500-3.jpg

In this last pic, notice the rectangular openings in the basket right below the magnet - these are vents filled with foam - six total. Then notice the hole in the cone right behind it. There are four of these, open to the dome underneath.

http://mark8.org/users/johnaec/1500-4.jpg

The rubber surround extends roughly 1/4" in front of the basket. And according to my bathroom scale, the E140 weighs 21 lbs. and the SUB1500 weighs 30lbs. There are some JBL numbering stickers in a couple places, and a circular white stamp on the basket that says (JBL Pro 29). The top of the magnet is labeled 1500 SUB. As near as I can measure, the mounting dimensions are standard for JBL 15" models.

The only cabinet I have available right now is 2.4 cu.ft. - I plan to drop it in this weekend, then test it both sealed and vented. Eventually, I hope to have them in ~4 cu.ft.cabs - 'second one is on the way...

John

Mr. Widget
02-26-2004, 07:45 PM
:D :D :D :D

jims
02-27-2004, 04:20 AM
Dang, John Have you been sleeping with those things?

4313B
02-27-2004, 05:24 AM
Nice photos!

PE said they sold over 120 of them yesterday.

Niklas Nord
02-27-2004, 05:36 AM
For us living in Sweden or the rest of Scandinavia,
it would be interesting to buy direcly from JBL in Denmark.
IF thats possible...

johnaec
02-27-2004, 05:38 AM
Originally posted by jims
Dang, John Have you been sleeping with those things? Don't tell my GF - she'll disown me!! :D

John

JuniorJBL
02-27-2004, 06:47 AM
I think I will try a vented box this weekend (unless it snows) to see just what kind of performance we can get, most likely about a 4 to 5 cu ft box.
It does work excellent in the sealed box though. And if you want space savings this is the way to go. Although not as efficient as my 2242 it is close!!
:D
LF extension is awesome and it really does not require that much eq. I was amazed at its detail for a VLF driver. It does sound quite good. As most people would use this for a sub/sat combo I would say don't use it above about 80-90 hz max at 24 db per octave. In the sealed box it gets a little "ringy" up there. If you do want to use it that high, I found rolling off about 100Hz with a mid "Q" cut buy about 5-6db then you can use it higher. Most of this could be the box though. The box is braced very well with medium amount of fiber fill although it might still fair better with another layer of .75 MDF. I am thinking about using 4 of these instead of 2 18's. In the sealed box I still save about 6 cu ft per side.
I will keep you posted.
Shane:D :D :D :D

Niklas Nord
02-27-2004, 07:07 AM
If you look at the plot on the details page on PE,
it shows to be nice up to 400hz approx..

it should be ok up to at least 200hz,
why dont you like it over 90hz ?

JuniorJBL
02-27-2004, 07:17 AM
I don't care for subs to go above about 70-80hz mostly I prefer below 60hz because I think they get a little directional. Now if you have 2 and they are very near your mains then that is a little different. But remember that is ONLY my opinon. As we all know audio is a personal prefrence and if we let others tell us what to like.... Im ranting sorry. Anyways if you like subs at 150-200 hz then by-all-means have some fun. I am sure at about 200 hz these will rattle your brain:bash:
Have fun Shane:D

jims
02-27-2004, 07:27 AM
Originally posted by johnaec
Don't tell my GF - she'll disown me!! :D

John

No problemo. She probably has some appliances
she hasn't told YOU about...

Jim

johnaec
02-27-2004, 07:36 AM
John

Looking at the MLSSA page I posted
Fs = 21.47 Hz
Fb = 46.61 Hz
Vb = 47.20 liters

from your formula Vas = Vb((Fb/Fs)^2 - 1), Vas should be 175.25 liters which isn't quite the 181.22 liters JBL calculated. Hmmm...I'll also have to check the numbers at the 25.4hz Fs PartsExpress states. I wonder how they came up with 128 liters VAS? I guess I'll have to calculate two designs, and see how different the specs are...

BTW - what does MLSSA stand for?

John

4313B
02-27-2004, 07:40 AM
"If you look at the plot on the details page on PE, it shows to be nice up to 400hz approx.. it should be ok up to at least 200hz, why dont you like it over 90hz ?"

Because it has substantial moving mass that's why. Have you looked at the amount of moving mass this monster is sporting?

"It is in a 2.2 Cu Ft sealed box. 2.5 with bracing and stuff. It sounds GREAT for the amount of space that it takes up."

"It does work excellent in the sealed box though. And if you want space savings this is the way to go."

Let us know when you have a pair running :)

JuniorJBL
02-27-2004, 07:42 AM
Originally posted by Giskard


Let us know when you have a pair running :)
Will do!!

4313B
02-27-2004, 07:43 AM
"BTW - what does MLSSA stand for?"

http://www.mlssa.com/

MLSSA-SPO
It's currently the T-S measurement package of choice at JBL.

Niklas Nord
02-27-2004, 08:55 AM
What kind of cone in the 1500 SUB ? Is it regular paper?
:rolleyes:

Strong?

johnaec
02-27-2004, 09:22 AM
Originally posted by Niklas Nord
What kind of cone in the 1500 SUB ? Is it regular paper?
:rolleyes:

Strong? 'Looks like regular paper to me. I imagine the oversize dust cover stiffens the cone substantially.

John

JuniorJBL
02-27-2004, 09:26 AM
It is a Kevlar impregnated paper cone.:D

4313B
02-27-2004, 09:28 AM
Good God that must have hurt!:eek:

JuniorJBL
02-27-2004, 09:34 AM
They do it :smsex: all the time!:bouncy:

Niklas Nord
02-27-2004, 10:32 AM
I just dont understand :D :confused:

sebackman
02-27-2004, 11:52 AM
Hello all,

Just ordered 4 for shipping to Europe. We can't have you guys in the US have all the fun all the time :p

Regards

//RoB

Niklas Nord
02-27-2004, 12:10 PM
Sebackman,

do you live in Sweden?
Is there any discount when ordering more than 4 of theese?
I guess there is customs to pay and so on... Ordering things
from the US.. :mad:

maxwedge
02-27-2004, 02:15 PM
Originally posted by JuniorJBL
I don't think so.:smsex:They do it all the time!:bouncy:


LOL!:rotfl: Hurt me with that one!:nutz:

Nice sub you guys.

JuniorJBL
02-27-2004, 04:54 PM
Originally posted by johnaec
I imagine the oversize dust cover stiffens the cone substantially.

John
The over sized dust cap is for cooling as well. Look at the pics of the holes in the cone.


Second box is done and I will be trying it out later on tonight.
:D :D :D :D

Alex Lancaster
02-27-2004, 06:32 PM
I think this Forum deserves a commission from Partsexpress.

Mr. Widget
02-27-2004, 06:39 PM
I am worried that we may have made them obsolete before I get my fill. I only ordered a few of them!!!!!:eek:

johnaec
02-27-2004, 07:28 PM
Originally posted by Mr. Widget
I am worried that we may have made them obsolete before I get my fill. I only ordered a few of them!!!!!:eek: It never ceases to amaze me how manufacturers always seem to discontinue some of the best stuff. Things don't take off to a fast start, so they think they aren't going to sell, and by the time people start finding out about them, they've been discontinued... :(

mikebake
02-28-2004, 07:12 AM
Originally posted by johnaec
It never ceases to amaze me how manufacturers always seem to discontinue some of the best stuff. Things don't take off to a fast start, so they think they aren't going to sell, and by the time people start finding out about them, they've been discontinued... :(

I would imagine that the truth here is somewhat different; these drivers apparently weren't made for mass public consumption. We're only talking 400 of them left, and those aren't the kind of numbers that a manufacturer is going to make money off of.
Heck, what do you think Parts Express paid for them?
Ya gotta think that they are just a decent bargain.
Someone mentioned that PE sold 120 of them Thursday or Friday..........

Get em while they last. They DO appear to be a nice driver. Giskard will be testing some soon, it seems.

johnaec
02-28-2004, 07:52 AM
...those aren't the kind of numbers that a manufacturer is going to make money off of.I guess I was thinking more of things like the outstanding studio monitors of the '80s and similar home systems, like the L65s. Now that they're not made anymore, they seem more in demand than ever. Whether people would buy them for what they'd cost to produce them now is another story, I guess...

John

JuniorJBL
02-28-2004, 08:15 AM
I now have 2 of these in 2.2 Cu Ft boxes. They "Just Do It" but we expect that from JBL's.
Anyways here are some pics and a few comparison shots of my 10cuft 2242. I have saved ALOT of space.

JuniorJBL
02-28-2004, 08:16 AM
Construction

JuniorJBL
02-28-2004, 08:17 AM
finnished

JuniorJBL
02-28-2004, 08:18 AM
BIG!!

JuniorJBL
02-28-2004, 08:22 AM
This is great too "IF" you can have 20-25 Cu Ft for 2 of them

mikebake
02-28-2004, 08:26 AM
Originally posted by johnaec
I guess I was thinking more of things like the outstanding studio monitors of the '80s and similar home systems, like the L65s. Now that they're not made anymore, they seem more in demand than ever. Whether people would buy them for what they'd cost to produce them now is another story, I guess...

John

There has been a fair degree of discussion on the forum over the last few years on this topic. As for being more in demand than ever, I'd think actually not, but who knows. Anyway, they still make a good monitor in the LSR series, and in fact, I believe I heard on the forum that bigwigs consider it the best monitor thye have produced, in many aspects. I would think that perhaps when JBL has moved on again, the LSR series will also be collectable.
MBB

David Dryden
02-28-2004, 08:30 AM
Junior JBL,

VERY NICE :yes: !

Just had a quick look at Partsexpress. Looks like they're all gone :(

Oh well.

Niklas Nord
02-28-2004, 08:34 AM
Everyone with big foam, rubber surroundings,
what do your pets think about them as a place to
do some scratching ?

get some of theese..


http://www.redcoat.net/pics/ToughLove.jpg

:D :D

JuniorJBL
02-28-2004, 09:01 AM
I don't have cats!:flamer:

Rex Mills
02-28-2004, 11:17 AM
Here is a cutaway of the JBL

JuniorJBL
02-28-2004, 11:24 AM
Originally posted by David Dryden
Junior JBL,

VERY NICE :yes: !

Just had a quick look at Partsexpress. Looks like they're all gone :(

Oh well.
They said they still had a few hundred but that they were going at a rate that would put them out of stock in about a week or 2 max!!
Shane:D

johnaec
02-28-2004, 12:45 PM
Originally posted by Rex Mills
Here is a cutaway of the JBL 'Just curious - where did that cutaway picture come from, (url?)? 'Any more info?

John

mikebake
02-28-2004, 01:44 PM
Just pulled one of my newly arrived sub1500's out of the box; definitely a nice looking driver. Apparently this driver is well-regarded within JBL as well (and it's designer has a pair in his home) and I can see why. Looking forward to the result! Heavy son of a gun, too!
I have to research a suitable plate amp to install and run these with. Any suggestions?

Alex Lancaster
02-28-2004, 02:58 PM
Mike:

I would use a couple of SR6670, in mono, amps currently on eBay, with an M552 or 3 or other suitable xover; For plate amps the PExpress 1000W are quick and easy, but I think the former combo is better.

Alex.

JuniorJBL
02-28-2004, 03:14 PM
I really like my Crown K2 for these subs. It can handle 4 of them in stereo/parallel (2ohms) at 1250wpc or 800wpc 4 ohms and they do not have fans. It is a great amp that can be had on ebay for a price around 600 used.
Shane


OOPS!
I re-read your post mike and saw that you said "plate amp". I have only used a few and was not that impressed. They are usually class D amps. if that is your route then the 1000w from PE might be the best thing. I just don't know much about these amps.
:D

speakerdave
02-28-2004, 04:15 PM
Originally posted by Alex Lancaster
I would use a couple of SR6670 . . ..
Those amps have two fans each.

David

Rex Mills
02-28-2004, 05:20 PM
Originally posted by johnaec
'Just curious - where did that cutaway picture come from, (url?)? 'Any more info?

John
The pic came from a google translated site, not just the transducer but the Revel sub

http://translate.google.com/translate?hl=en&sl=it&u=http://www.audioclub.it/audio/prodotti/REVEL/revelsub15le1.htm&prev=/search%3Fq%3Drevel%2Bultima%2Bsub%2B15%26hl%3Den%2 6lr%3D%26ie%3DUTF-8%26sa%3DG

mikebake
02-28-2004, 06:57 PM
Nice lesson in Italian. Anyway, I'm beginning to think that I'll have to seriously power these dudes, and the PE plate amps may not really be up to it. I do have my QSC's, which are quite good as sub amps; I just don't like the fan noise................

mikebake
02-28-2004, 06:58 PM
Widget, what is your execution with these going to be?

Mr. Widget
02-28-2004, 07:16 PM
I plan on testing them in 4 and possibly 5 cu ft ported and sealed boxes. I have a pair each to play with. I will probably also try them out in a pair of 1.5 cu ft sealed boxes as that is what they were originally designed for. For the sealed boxes I will be using some bass boost. For amplification I currently use a JBL MPA 600 which I run the 4 2235 subs in my HT. Into 4 ohms it is rated at 660 wpc and 960 wpc into 2 ohms. It is fan cooled, but with the relatively light use I give it in my HT it never warms up enough to kick the fan on. Since these woofers are a bit less efficient and I may run 2 per channel yielding a 2 ohm load, I may have to live with a fan or source a different amp. This amp does have great control for bass so I hope the fan doesn't become a problem.

JuniorJBL
02-28-2004, 08:02 PM
I now have them in the corners behind the 250's and IT IS INCREDIBLE!!!!
They blend so very nice. I think I have listened to 150 different tracks in the last 2 days. Acoustic bass on, well, anything is just awesome. They are crossed over at about 65-70hz 24db, 5db boost at 20hz and a Q of 1 on my RANE SP15 and they play anything. From Diana Krall Live in Paris to Dire Straits Brothers in Arms to Pink Floyd Welcome to The Machine to Telark recordings and many many others(DVD Audio,CD, SACD). These are VERY cool.
I am ordering 2 more and will try a box that houses 2 woofers for acoustic coupling per side.
Very Fun!!:D :thmbsup:

johnaec
02-29-2004, 09:03 AM
Thinking down the road some, how do you think this would work for a 4-way system:

1500 SUB
2012H - crossover 180 or 300hz
2118H - crossover 800 hz
2404H - crossover 3Khz

Cabinet 4-6 cu.ft. tuned ~25hz

I'm looking forward to possibly consolidating everything into just two relatively small cabinets, and other than probably having to adjust levels via bi/triamping and active/passive crossovers, (31 band EQ also available), wondered how these components would play together? I know JBL used the 2118H/J and 2404H together in a couple different Cabaret systems - is this combination worthwhile for hi fidelity and HT also? Could the 2218 possibly even take the place of the 2012, or the other way around, for a 3-way system? How does the very high end of the 2404H compare with the 077?

If this works, I may not need my L65A and L150 speakers anymore. :hmm:

John

David Dryden
02-29-2004, 04:14 PM
Well, add me to the list of Sub1500 owners! There's two on the way with my name on them! :D

Can't wait to get the boxes built and fire 'em up! For now they'll go in the music room system, but eventually they'll wind up as part of the music/HT system downstairs. JuniorJBL, how's life with them so far?:coolness:

JuniorJBL
02-29-2004, 06:28 PM
Originally posted by David Dryden
JuniorJBL, how's life with them so far?:coolness:



I do think that they are some of the best sounding subs I have ever had. They are only second to my JBL 2242 in a 10 cuft box. a very close second!!!!!:D :D :D :D

David Dryden
02-29-2004, 06:32 PM
Good deal! Can't wait to get mine. Still trying to decide on a crossover though :hmm:

Niklas Nord
03-01-2004, 01:44 AM
JuniorJBL,
do you really think the 2242 are better in producing
sub -output than the 1500 ?

4313B
03-01-2004, 03:56 AM
Niklas, I thought you had heard Neriks' system?

At any rate, even the designer of the SUB 1500 / REVEL 15 puts it second only to the 2242H.

Niklas Nord
03-01-2004, 04:01 AM
Why is this?
The 2242 does not put more output under 30hz ?
or does it.

The 1500 should easily make some 16hz with better SPL

Niklas Nord
03-01-2004, 04:06 AM
Is there any measurements or simulations of
the SUB1500 ?

Freq response and Phase, Delay

It would be really interesting to see if they can
make it up to 160hz ...

Almost 5cm p-p, it has to be able to put out
some serious SPL.
Has anyone been testing it to the MAX yet?

4313B
03-01-2004, 04:19 AM
Originally posted by Niklas Nord
Why is this?
The 2242 does not put more output under 30hz ?
or does it.

The 1500 should easily make some 16hz with better SPL At minimum, the 2242H is capable of 3 dB greater output at 20 Hz (non-EQ'd) and that's only if you run the SUB1500/REVEL15 in a vented box to increase it's SPL output. By design, the SUB1500/REVEL15 is intended for small sealed enclosures.

Niklas Nord
03-01-2004, 04:22 AM
Aha, thats interesting. SO if we take for example, Neriks
system with the 2242 tuned to 27hz, would theese
outperform, letīs say 4 SUB1500 ?

What about distorision?


And what about SUB1500 vs 2245?`then?

JBL 2242
JBL SUB1500
JBL 2245
JBL 2235

? Fair list?

4313B
03-01-2004, 07:39 AM
What are you trying to accomplish?

If it is maximum SPL at 16 Hz in your house then you might want to opt for as many REVEL 15's as you can fit in your space.

If maximum SPL per transducer is required down to 20 Hz then go with a 2242H/4645C.

The REVEL 15 takes twice the enclosure volume to go as low as the old 12" 121A/121H-based B212 Ultrabass. It will thoroughly spank the old B212 in pretty much every aspect while maintaining the same bandwidth. The B212 was a 2.0 cubic foot volume, the REVEL 15 requires a 4.0 cubic foot volume to accomplish the same bandwidth without EQ. The B212 wasn't EQ'd and the old 121A/121H driver cannot handle any EQ and still maintain any kind of power handling capacity. The REVEL 15 can be put in enclosure volumes as small as 1.5 cubic feet and then EQ'd. It can physically and electrically handle the EQ. If you port the REVEL 15 it might be necessary to run a high pass filter to protect the driver from unloading below resonance depending on how hard you drive it. Although a 4.0 cubic foot volume for a REVEL 15 is entering the realm of infinite baffle as opposed to acoustic suspension (just like the old B212 with the 121A/121H) there should still be some restoring force available to somewhat protect the driver better than a vented enclosure would.

The 2242H and 2245H are best limited to 20 Hz and above in large 8.0 + cubic foot volumes. They can be run with and without EQ. They should be run with 20 Hz high pass filters to protect them when they unload below resonance. These are the drivers the big boys use in the world of Cinema Sound where extreme SPL is required along with very low distortion and power compression. These 18" drivers can move sooo much more air with sooo much less effort that to compare them to any of the 15" drivers for shear overall output is rediculous.

The REVEL 15 makes an outstanding VLF transducer when used in a Home listening environment. It has not and will not supplant 2242H's, or even 2245H's, in the world of large venue VLF sound reinforcement.

4313B
03-01-2004, 09:25 AM
"I am ordering 2 more and will try a box that houses 2 woofers for acoustic coupling per side."

Cool! That should reduce any IM distortion quite a bit and you should still end up with a pretty small physical package, especially if you go the 1.5 to 2.0 cubic foot per driver + EQ route :)

What are the physical dimensions of your current test boxes?

JuniorJBL
03-01-2004, 09:57 AM
Outside dimensions:
h=17.5
w=15.5
d=20.5
thickness=.75
Look at the pics for constuction. There is also a woofer cutout (inside cutout) glued to the inside rear wall of the box.

PS Could you pm me on my last message about 2 more drivers.
Thanks Shane

sebackman
03-01-2004, 10:23 AM
Hello all

Thank you for all the info. from everybody. Great stuff as usual. :)

Shane, I saw that you used 0,75" material in your boxes. How do they hold up when you let loose all of your Crown power. :rolleyes:

Is 0,75" MDF thick enough? When I look at the info in the Revel B15 manual it seems like they used VERY thick walls. Is that called for?

I'm going to build two of them and bout 2,5 cu ft each, with a layout similar to yours.

How much power do you guys think is minimum needed to run these drivers with a little bit of EQ (let's say +3db at 20Hz, XO at at 15HzHP & 70Hz LP, 24/24 db) in 2,5 cu ft boxes. Just a ball park figure.

Please advise.

Thanks

//RoB

JuniorJBL
03-01-2004, 10:53 AM
If I keep these I will layer another .75 piece all the way around.
They do have some week spots.

A very good question indeed!!
if you are sure of your size go for at least 1" with heavy bracing!!
If it is a test box, build it then beef it up. It is nuch cheeper to use 2 pieces of .75 than special order 1.5 MDF $$$$$ (about $80 per sheet and it ways a ton maybe more) I made my cab for my 2242 out of 1.25 mdf and it was about 250Lbs per sheet!!:D

Alex Lancaster
03-01-2004, 02:11 PM
Hi:

I will soon post pictures of my BIG MONITORS, I have some noise problems to work out; with 4 2245īs in 280 liter cabs each, with Telarcīs 1812, the back wall, steel reinforced concrete and red brick , vibrates reassuringly just before the Crown K2 clips; for my entertainment, I am installing 4 Aura bass shakers with a SR6630 amp, a joke on my "audiopedohile" friends.

Alex.

boputnam
03-01-2004, 02:36 PM
Originally posted by Giskard
The 2242H and 2245H are best limited to 20 Hz and above in large 8.0 + cubic foot volumes. They can be run with and without EQ. They should be run with 20 Hz high pass filters to protect them when they unload below resonance. These are the drivers the big boys use in the world of Cinema Sound where extreme SPL is required along with very low distortion and power compression. These 18" drivers can move sooo much more air with sooo much less effort that to compare them to any of the 15" drivers for shear overall output is rediculous.

Image of Ian, enjoying his new 4345's... :coolness:

Mr. Widget
03-01-2004, 04:49 PM
Come on Bo. Admit it. Maxell took that photo of you years ago enjoying your L-100s.:D :D :D

jblnut
03-01-2004, 05:09 PM
Thanks to you guys I'm $283 poorer than I was this morning, but I''ll be oh so happy to see my UPS guy in a few days. Mine will be going into a ~8 cu ft folded horn enclosure that started life as a Crate 15" bass bin. It's been my HT sub for several years but has started to reveal limitations lately when pushed. The cheapo driver in there just can't take everything my bridged Carver PM175 can dish out.

Looking forward to the weekend !

Thanks for the heads-up whoever saw these to begin with !

jblnut

JuniorJBL
03-01-2004, 05:20 PM
Originally posted by pangea
Hi!

I don't know if this is interesting or not, but I found this ad at parts express, if anyone is looking for a JBL sub.

JBL SUB1500 15" SUBWOOFER 4 OHM
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-750&orefer=esf021904-299-750

BR
Roland

Dibs for Roland!!!!:D Thanks

Mr. Widget
03-01-2004, 05:24 PM
I currently have nine of these bad boys downstairs... no I am not that greedy I will be sharing some of them.:)

I hope to fire them up tonight!

David Dryden
03-01-2004, 06:52 PM
Any verdict yet Mr. Widget? Inquiring minds (and ears) want to know! :bouncy:

boputnam
03-01-2004, 06:57 PM
Originally posted by Mr. Widget
I currently have nine of these bad boys downstairs... You, sir, have a Problem... Me thinks it is 2245H envy, but I've only seen it a few dozen times... :nutz:

Mr. Widget
03-01-2004, 11:16 PM
Before any break-in and looking at these beasts, I would imagine a fair amount of break-in will be required, I am getting -6 dB at 20Hz at my listening position. I have a pair of them running in my rather large HT in 5 cu ft boxes tuned to 21 Hz. Unlike my quad 2235 setup playing the DTS intro sounder at 105 dB, I did not detect any appreciable distortion. With the 2235s at this level they would always exceed Xmax with the unfortunate telltale sound of slamming mass rings at the very end of the sounder when a loud fairly muddy very deep noise is played. The quad 2235s at the same listening position in (4) 5 cu ft boxes tuned to 29Hz are about 6- 9 dB lower at 20 Hz.

So test one. They are louder and lower than the quad 2235s. I do have a pair of 2245s but unfortunately have no extra refrigerators sitting around to mount them in.:D

Test two. How do they sound? Couldn't tell ya. I have a head cold and the deep bass was giving me a splitting headache. I put on the Matrix at 105dB peaks and my wife and I left the building to let them break in a bit.

More to come later. I do intend on trying them in small sealed boxes as well.

Widget

PS. I almost forgot. Polarity convention! Hey Bo write this down, with a positive voltage on the red terminal there is forward cone motion. I expected this from Revel, but the beasts say JBL on 'em and they really are beautifully made. As pretty as a brand new 60's LE15A.

JuniorJBL
03-02-2004, 07:06 AM
Originally posted by Mr. Widget



PS. I almost forgot. Polarity convention! Hey Bo write this down, with a positive voltage on the red terminal there is forward cone motion. I expected this from Revel, but the beasts say JBL on 'em and they really are beautifully made. As pretty as a brand new 60's LE15A.


I have found almost all JBL drivers made now have forward cone movement like the 2241-2242-2226 etc. I was also told by Dave (in service) at JBL PRO that some 2245's were this way as well.

And I do think they are quite beautifull. That is one thing about a JBL is it looks so very well built. Even when people did not know how to make a speaker (stamped steel frame...) here was JBL!!
Shane

Very cool Mr. Widget!!:D

Niklas Nord
03-02-2004, 07:28 AM
What is the L1 and L2 values in the plot on page 2 ?
Is it LE ? Why two values?

Niklas Nord
03-02-2004, 09:45 AM
How many of you has been testing this nice one yet?

boputnam
03-02-2004, 10:16 AM
Originally posted by JuniorJBL
I have found almost all JBL drivers made now have forward cone movement (on positive to red)... I was also told by Dave (in service) at JBL PRO that some 2245's were this way as well. That's it then.

Nothing is sacred...
There is no dog...
I have no purpose...

:rolleyes:

JuniorJBL
03-02-2004, 04:38 PM
Originally posted by boputnam
That's it then.

Nothing is sacred...
There is no dog...
I have no purpose...

:rolleyes:
You must point out that I forgot to put "positive voltage on the red terminal" provides forward cone movment:bash:

I stand corrected!! Thank you !!May I have another!!!!:D

boputnam
03-02-2004, 06:23 PM
"Corrected..." - I think not. :no:

Merely edited for clarity's sake.

Er, unless of course you DID mean positive voltage to Black terminal = outward cone movement. Then, well... :spin:

:rotfl:

JuniorJBL
03-02-2004, 06:37 PM
Originally posted by boputnam
"Corrected..." - I think not. :no:

Merely edited for clarity's sake.


:rotfl:
I do thank you and I must say you bring much wisdom to the forum!!:D
Shane

David Dryden
03-02-2004, 06:50 PM
:bouncy: The 1500's are scheduled for delivery tomorrow! :bouncy:

I feel like a kid on Christmas eve!

I'm going to build sealed enclosures for them. Any more thoughts on what volume to build?

mikebake
03-02-2004, 07:03 PM
Originally posted by David Dryden
:bouncy: The 1500's are scheduled for delivery tomorrow! :bouncy:

I feel like a kid on Christmas eve!

I'm going to build sealed enclosures for them. Any more thoughts on what volume to build?
There was discussion earlier in the thread, or wait until Giskard and Widget weigh in again.................

David Dryden
03-02-2004, 07:30 PM
Yeah, I was actually hoping Giskard, Widget, and Shane would report in with more results. BTW, that's an interesting creation, er uh, speaker, Mike. WHAT IS IT??? :eek:

JuniorJBL
03-02-2004, 09:27 PM
OK!
I have had them in 2.2 cu ft boxes and I have not tried the bigger vented counterparts but with what I am seeing (or better yet.. hearing) these are by far the best small box sub I have ever heard. Better than the velodyne and so on. I am using 2 of them and as giskard said you should always use them in pairs, no matter what the size. They are not one note subs and they are very musical as we expect from JBL transducers. Yes the 2242 does sound a bit better with an added 7.5 cu ft per driver. I can fit 4 of the 1500 sub's into about 12 cu ft of space where the same 4 18's would be about 44 cu ft. not that 4 15's could compare with 4 18's but that is where I was heading. If you refer to my earlier post in this thread, I am using an EQ with the system and the savings in space is great. It allows me to put them right behind my 250's and they blend so very nice and if I want to turn them up....

I have broke a vase upstairs in the kitchen. Vibrated it right of the shelf!! These are nothing short of amazing!! And they look cool too!!:D

I am going to wait to hear what Giskard and Widget say about there vented boxes. I am curently building a jig to do speaker measurments on my computer so as I can post them here. I will keep everyone updated. As a side note I will be getting 2 more and I will let everyone know how that goes.

My room is small at this time but I am in constuction of a new room as of a week ago. So I should have more for you as time goes on.

I would like to thank all of the people who keep this forum up as this is a great place to be!!!:wave: :thmbsup: :dancin: :rockon2: :band:

Niklas Nord
03-03-2004, 01:03 AM
Is there any information regardning distorsion from this
SUB 1500 ? Can it outperform the 2245 regardning this?

When you are using sealed subs, are you using EQ then?
It has to be alot of power added to this kind of design,
doesnīt it :rolleyes:

Couse Revel used some 800 horsepower to their deisgn. :eek:

Will someone try pushpull with theese drivers perhaps !

Niklas Nord
03-03-2004, 03:45 AM
Does someone know if PartsExpress are running out
of drivers soon?

The sub1500

4313B
03-03-2004, 04:09 AM
Yes Niklas the 1500 SUB / REVEL 15 has lower distortion than the 121/124/2203/136/2231/2235/2245 drivers.

Niklas Nord
03-03-2004, 04:12 AM
How do you people get in touch with PartsExpress?
I have been sending them several mails regarding
that we are some people in Sweden wanting to
test this driver.

And wants to know if some kind of better price can be
accomodated when ordering 20+ drivers..

No answer from PE

maxwedge
03-03-2004, 05:03 AM
Their not out of stock yet, Niklas, because I ordered 1 on monday and it should be here on friday. I think I'm gonna build a coffe table for it!:D Anyone have any info on down firing subs? Like pros and cons. This things going to be near feild for HT only. I already have 2242's in my L&R, lol.:)

mikebake
03-03-2004, 05:41 AM
Originally posted by David Dryden
Yeah, I was actually hoping Giskard, Widget, and Shane would report in with more results. BTW, that's an interesting creation, er uh, speaker, Mike. WHAT IS IT??? :eek:

I'd tell you but then I would have to.................

It's Todd Michaels design; he built it for fun to run mono! Kinda neat, eh? He works with Bill Woods, who has been a horn designer since, uh, the around 1970. They currently work in the pro audio world in Canada. Figured some of you guys would get a kick outta it.

4313B
03-03-2004, 05:52 AM
Originally posted by maxwedge
Anyone have any info on down firing subs? Like pros and cons. This will give you the approximate amount of sag:

Cms x Mms x G

This might be easier:

http://www.partsexpress.com/resources/downfire.html

In any case, I would think 300 grams of moving mass is quite a bit to mount face down or face up.

boputnam
03-03-2004, 07:14 AM
Originally posted by David Dryden
BTW, that's an interesting creation, er uh, speaker, Mike. WHAT IS IT??? :eek: Yea, me too...? And, from what I've read and think I understand about how lenses work this configuration would be directing the sound about +25-30 degrees up - along the axis of the throat of the horn. :confused: Is that intended?

Maybe I should :duck: - my ignorance is quite exposed here...

maxwedge
03-03-2004, 09:22 AM
Originally posted by Giskard
This will give you the approximate amount of sag:

Cms x Mms x G

This might be easier:

http://www.partsexpress.com/resources/downfire.html

In any case, I would think 300 grams of moving mass is quite a bit to mount face down or face up.

Good thing I didn't tell the wife yet that I was gonna build her a new coffee table:D . Thanks again.:)

David Dryden
03-03-2004, 09:30 AM
They're here! :bouncy: Can't wait to try 'em out!

On the down side, the Crown crossover that I was going to bid on got yanked by the seller. :( Guess he got cold feet (the bidding wasn't up very high). Oh well, the search goes on. There is another, but it looks kinda rough. I think I'll wait for one in a little better shape.

mikebake
03-03-2004, 10:51 AM
Originally posted by boputnam
Yea, me too...? And, from what I've read and think I understand about how lenses work this configuration would be directing the sound about +25-30 degrees up - along the axis of the throat of the horn. :confused: Is that intended?

Maybe I should :duck: - my ignorance is quite exposed here...

Sorry, correction/brain fade; it is Todd Michaels design, not Todd Whites!!! I will get the details on it.

Niklas Nord
03-04-2004, 11:45 AM
How big are the Crates for the driver?
Is it 40lbs in weight?

Are they packed in bigger crates involving more drivers?
Like, 4 drivers packed in one crate?

Any pictures of the crate perhaps..

mikebake
03-04-2004, 11:49 AM
Mine were individually boxed, one 1500 per box, and the weight is something like 45lbs for shipping.
BTW, on the photo of Todd Michaels mono horn speaker above, here is what he said about it;

"JBL masher with BMS 4538 1"
RCA 1428 on JBL 2395 lens
Two 45 Hz rear load horns driven by two TAD TL1101 woofers.

This system is in storage right now and I'm currently running two of the new U15 Unity cabinets I designed for Yorkville. Some day when I win the lottery (or get very lucky) I hope to acquire another RCA1428 and design another stereo system around a pair of those amazing drivers. I'm still working on a design for the low section to run with the U15's, maybe two 12" woofers in 7cubic feet with two 15" passives. "

Cool.

Niklas Nord
03-04-2004, 12:35 PM
Do you have the outer measurements of the box?

4313B
03-04-2004, 12:39 PM
Yes

David Dryden
03-04-2004, 12:51 PM
Originally posted by Giskard
Yes

Niklas, I think you're going to have to be more specific in your request... :rolleyes:

:rotfl:

Niklas Nord
03-04-2004, 01:34 PM
:(
You are not very nice !

:D

4313B
03-04-2004, 02:06 PM
Oh Niklas you know my life would lose all meaning if I couldn't rib you...

21" x 21" x 9"






(Actually I had to wait until I got home to measure one :p)

Niklas Nord
03-04-2004, 02:40 PM
Thank you R. !!

dougzilla
03-05-2004, 09:21 PM
I ordered 2 today from PE. In stock. Shipped. Spoke to a salesperson a few minutes after ordering to ask about something else and at the end asked if these were almost gone. She said there were "over a hundred" left. Hmmm.....

maxwedge
03-06-2004, 06:18 PM
Plugged up an old Fisher box for now....sounds really nice. As good as the 2242's, in my living room. The 2242's will kick butt in a bigger place. :dancin: I think I should get another before their gone.:banghead:

mikebake
03-06-2004, 07:51 PM
Maxwedge, what is on top of the big screen? Something you are doing for center channel?
MBB

maxwedge
03-06-2004, 09:17 PM
Hi Mike,:yes:
Yeah thats my center channel. 2370 horn/2461 driver, 2012 10" mid and the sub1500 as the sub for HT. I have a 035T1A for the highs....can't really afford any 2404's or 2405's right now.:( A test box for the 10" is almost done but I'm rethinking the baffle.

JuniorJBL
03-06-2004, 10:06 PM
Originally posted by maxwedge

....and the sub1500 as the sub for HT.

Do you get interference from it on your mits being so close?
(to your screen)
Shane

maxwedge
03-07-2004, 08:14 AM
Originally posted by JuniorJBL
Do you get interference from it on your mits being so close?
(to your screen)

You mean form the magnet?..... No it's a rear projection and not a ctr. From vibration?....yes!:D It has a dust and light diffusion screen on the front that I need to insulate.

Scott

JuniorJBL
03-07-2004, 09:56 AM
I have a Pioneer Elite pro510HD Rear Projection CRT and if I am not careful I have lots of problems. I need at least 3ft of clearence (from were the guns are mounted inside).
Shane:D

Niklas Nord
03-09-2004, 01:15 PM
More feedback folks :D
How does the sub turn out to be?
GREAT?

jblnut
03-09-2004, 06:32 PM
I installed mine last Friday night. It replaced a crappy stamped-steel frame 15" driver in a Crate 6 cubic foot bass bin I used to use when I was in a band. Because this new driver sticks so far out in front (the rubber surround) I had to figure a way to bring the protective screen up about 3/4". Other than that it was a 5 minute swap. Saturday morning everyone was out of the house so I let 'er rip. I put in the Clapton "one more car" DVD that I've been getting into lately and was completely blown away by the accuracy and musicality of the bass. And quantity ? I can make things in the walls and floor rattle that I've never heard before
:-). It's not as efficient as the driver that was in there, but my Carver (PM175) wasn't even warm to the touch after an hour of loud music. I think I'm going to like it a whole lot - and for $268 delivered ? Probably one of the best bang/buck upgrades I've done. It's complete overkill for most listening situations, but like I always say - there's no kill like overkill :-).

jblnut

PS - I can't IMAGINE anyone needing more than one of these in any normal home listening environment.....

David Dryden
03-09-2004, 06:37 PM
Any more conclusions on the optimum box size (sealed)?

4313B
03-09-2004, 06:53 PM
"PS - I can't IMAGINE anyone needing more than one of these in any normal home listening environment....."

They said that when the Hartsfield came out too...

In these trying times there are concepts such as standing waves and room nodes that multiple point sources help to alleviate. If one still hasn't gotten the hint yet then feel free to just run one.

Mr. Widget
03-09-2004, 06:57 PM
Originally posted by jblnut

PS - I can't IMAGINE anyone needing more than one of these in any normal home listening environment.....

Damn! I've ordered a total of 19 of them. Is that overkill?:D :D :D

Seriously, I am using a pair in 5 cu ft boxes tuned to 21 Hz and they are tight, musical, deeeeeep, truly remarkable. The system that they are running in is my HT (aprox. 6500 cu ft / 183.5 cu m room) so they have to keep up with my Left-Center-Right Meyer UPA 1 clones that each get 400wpc. They do the job that the quad 2235s couldn't. The quad 2235s were about 6-7dB more efficient at 50-60 Hz but each sub gets it's own 600 watts and so far no clipping. (No ear bleeding either. It really isn't that loud. Honest Mom!)

Over the weekend I put another pair in 1.5 cu ft sealed boxes. Without EQ they don't extend quite as low and they seem to be a bit louder in the upper bass and have a bit of one note bass. In the near future I tend to play with the sealed boxes with both a digital and analog EQ to see how they work out. They really were designed to be driven in a small sealed and EQ'ed box. With no EQ though the 5 cu ft boxes are great!!!

Widget

Mr. Widget
03-09-2004, 07:10 PM
In these trying times there are concepts such as standing waves and room nodes that multiple point sources help to alleviate. If one still hasn't gotten the hint yet then feel free to just run one.

This is a really good point Giskard. I have a different system that resides in our "Living Room". For aesthetic reasons I have one 10" Velodyne HGS sub hidden in a cabinet. I have it tuned to sound right in the sweet spot, but as you walk around the room there are some nodes that are quite pronounced. At the dinning table some 15-20 feet away from the sweet spot there is a strong reinforced node that can be annoying.

Widget

jblnut
03-09-2004, 07:19 PM
I thought I was a jblnut....I'm not even in the same league as you guys !

Nice hanging out with y'all just the same....


jblnut


PPS - can't you just sit in a different location if your particular seat happens to be in a non-optimal standing wave reinforcement zone? Don't you introduce more cancellation problems with multiple sound sources ? Just curious....

Niklas Nord
03-10-2004, 01:53 AM
This is great guys!
:D :D :D :D :D :D :D :D


There is many thing to do with room acoustics if you have,
lets say 4 sub-modules. Depending on your room measurements.
And proportions. And how the listening is aligned.

boputnam
03-10-2004, 08:03 AM
Originally posted by Mr. Widget
At the dinning table some 15-20 feet away from the sweet spot there is a strong reinforced node that can be annoying. Roomate...? :rotfl:

19 of them!!?? Widget - you are on VLF probation! :scold:

Now, finish-up your work like a good Widget and provide us
Originally posted by David Dryden
...conclusions on the optimum box size (sealed)? :yes:

Ralf
03-10-2004, 09:55 AM
Originally posted by Mr. Widget
Damn! I've ordered a total of 19 of them. Is that overkill?:D :D :D

Widget

Oh Mr. Widget...you will lose your wife.

Believe me. I have also no more...

Greetings
Ralf

David Dryden
03-10-2004, 05:14 PM
Please forgive my ignorance, but is a Qtc of .7 considered to be "optimally flat"?

David Dryden
03-10-2004, 05:28 PM
It sure is nice having all of this knowledge available to us "rookies"! Thanks for all of the research and info! Until I get my garage built (this Spring-Summer), building speaker boxes is not the easiest thing to do - no room to work. :( It would be nice to be able to "get it right" on the first box! I'm anxious to fire these babies up!

jim henderson
03-11-2004, 10:32 AM
I just got my pair. These things are GORGEOUS!

I can't wait to design a pair of end table/cabinets for these.

Thanks again for all your help guys!

John Y.
03-11-2004, 02:33 PM
Some of you may remember that I went through a design process a while back where I intended to convert a Lansing C37 cabinet I built in 1957) to house a 2245H by enlarging the volume (extending the depth) to get 8 cubic feet. By procrastinating, I now don't have to do extensive mods.

With the PE deal, I can use a 1500 in the cabinet and, with only doubling the panels on the inside and cross bracing, I can easily get 5 cubic feet without touching the exterior. I immediately ordered two 1500's so that I can try the mod and then either duplicate the cabinet or build two new sealed boxes, if that solution seems better. I await the results of all the testing going on.

Mr. Widget, your results with the 5 cu ft tuned to 21 Hz sound great. What size duct was used for your tuning?

Thanks to the forum for the alert.

John Y.

Mr. Widget
03-11-2004, 03:34 PM
Originally posted by John Y.

Mr. Widget, your results with the 5 cu ft tuned to 21 Hz sound great. What size duct was used for your tuning?


John Y.

Well first of all let me second your call for procrastination!

For my initial test I pulled a pair of 2235s out of their 5 cu ft boxes and plopped the Revel subs in there. The 2235s called for a tuning of (2) 4" dia ducts that are 11" in length. Since capping one of these ports yields a tuning of 21Hz, that was the approach I took for my initial tests. This port is not recommended for the ultimate solution as it yields a very high vent velocity which will produce audible noise at certain frequencies at higher power levels.

A 5" dia port that is 19" long will yield better results. A square port that is 4.25" X 4.25" that is 17.31" should also be satisfactory.

I hope this helps.

Widget

John Y.
03-12-2004, 09:57 AM
Mr. Widget,

Would any duct (or ducts) that were 8 inches or less satisfy the 21 Hz tuning requirement for a 5 cu. ft. cabinet? The C37 cabinet has only 13 inches internal depth from the front of the speaker baffle to the rear panel. A single 5.25" dia hole (originally for the 075) and a 3 x 13.5" rectangular vent are in the baffle panel aside from the 13.5" circular driver mounting hole. If necessary, I could cut a duct hole in the side or in the bottom if I put the enclosure up on 5" wooden legs. The bottom is preferable for aesthetic reasons, so the cabinet could retain its retro effect.

BTW, how do you figure your tuning? Is it by BB Pro, or by experimental measurement?

Thanks for your help. My drivers will arrive on or about the 16th, so I have to get cracking on the design. Maybe I should alternately consider putting both drivers in the same 5 cu ft cabinet. Think that would work? If so, maybe I should order two more.

John Y.

4313B
03-12-2004, 10:08 AM
"BTW, how do you figure your tuning? Is it by BB Pro, or by experimental measurement?"

There is only one way to "figure" tuning and that is by measuring it. The math programs can be quite effective at getting one close but they aren't 100% every time. Two people can build what each thinks is a 5.0 cubic foot volume and end up with different effective volumes depending on total system losses.

boputnam
03-12-2004, 10:17 AM
Originally posted by John Y.
The C37 cabinet has only 13 inches internal depth from the front of the speaker baffle to the rear panel. Hey, John...

You can put a bend in the duct, if need be. You may know that JBL often did this, for space reasons, and also perhaps to keep the duct-end a minimum of 3-in from any cabinet wall. You can use 90-degree elbows... :yes:

Mr. Widget
03-12-2004, 11:23 AM
Originally posted by Giskard
"BTW, how do you figure your tuning? Is it by BB Pro, or by experimental measurement?"

There is only one way to "figure" tuning and that is by measuring it. The math programs can be quite effective at getting one close but they aren't 100% every time. Two people can build what each thinks is a 5.0 cubic foot volume and end up with different effective volumes depending on total system losses.



I too am generally obsessed with details. That said, I have discovered that in most cases being "off" by an inch or so in port tuning is readily measurable but unless you listen to test tones absolutely inaudible. In most cases I am too lazy to set up and verify that which my ears are happy with. Now if I am not happy with the outcome, that's another story. In the old days when I used inaccurate charts to "calculate" bass tuning, I often had to go back and re-tune, measuring the resonance peaks etc. Since using BBPro6, I have been very pleased with the results... so far. I have only used it with a handful of woofers, but the results have been surprisingly as predicted.

As for different 5 cu ft boxes, well there do seem to be discrepancies there. The "5 cu ft" boxes that I am using started out as 5.41 cu ft. Then I subtract out the cross bracing and ports and woofer volume. (BBPro6 suggests a 5.39 cu ft box to achieve a 5 cu ft before any bracing.)

John,

You are discovering one of the primary reasons that passive radiators exist. It is sometimes difficult to fit a port in the box. I would recommend you put the port on the bottom of the cabinet. The larger the dia the longer it needs to be. Multiple small ports would also need to be longer. I assumed you would have this problem and that is why I suggested the two ports I did. They are sort of the best compromise for vent velocity (air noise) and port length.

I still haven't gotten around to tuning the EQ of the sealed box, but with out some EQ tweaking the bass isn't quite right. The 5 cu ft solution sounds great with no EQ. Hopefully others will offer their opinions and describe how they are using theirs.

Widget

4313B
03-12-2004, 11:32 AM
"unless you listen to test tones absolutely inaudible."

Ooops! There is other stuff to listen to??? What have I been missing???

"Since using BBPro6, I have been very pleased with the results... so far. I have only used it with a handful of woofers, but the results have been surprisingly as predicted."

Ditto! :yes:

Mr. Widget
03-12-2004, 11:35 AM
Originally posted by boputnam
Hey, John...

You can put a bend in the duct, if need be. You may know that JBL often did this, for space reasons, and also perhaps to keep the duct-end a minimum of 3-in from any cabinet wall. You can use 90-degree elbows... :yes:

....Or, using your available 3x13.5 in rectagular opening, you could build a duct of 9.566 in length for the 373.064 cu.in.

NB: All duct lengths include the baffle thickness.

If you use an elbow, I would certainly make it longer than you think you need and follow Giskard's advice to trim and measure.

Bo,

Helmholtz resonators aren't based simply on volume. According to BBP6 the 3"X13.5" port would need a duct that was over 44" long. To over simplify it, as the mouth area increases the duct length must increase to maintain the same frequency.

Widget

boputnam
03-12-2004, 12:46 PM
Hey, Widget...

Yea, I caught my error (thanks Claus! :yes: ) - that's why I deleted that portion of the post. :banghead:

If John was to use the 5.25 opening, it looks like the duct would have to be increased to at least 21 in length - right?

I dunno - I need to check all this when I get home... :smthsail:

John Y.
03-12-2004, 07:36 PM
"Helmholtz resonators aren't based simply on volume. According to BBP6 the 3"X13.5" port would need a duct that was over 44" long. To over simplify it, as the mouth area increases the duct length must increase to maintain the same frequency.- - Widget"

How, then, can the JBL 4641 or 4645C cabinets be tuned to 25 Hz (as they claim) with an (approx) 8" duct when the cabinet is less than 18" deep, unless they have a bend in the duct (which I doubt)? Yhese are 8 cu ft cabinets. Does cabinet size make that much difference?

Mr. Widget - I gather that measuring the resonant peaks is the best way of determining the system resonance, that is, resonance occurs half way between the peaks. That right? I like your idea of bottom duct placement being a good compromise, Now, if only I could find some JBL stilleto aluminum legs (circa 50's), I could have a real retro (looking) rig.

jcdahl
03-12-2004, 08:32 PM
I wonder what two of these things would sound like replacing LE15s in a Paragon?

Wow I couldn't wait to try them so I just ordered two for myself. They must still have some left.

Chas
03-12-2004, 09:30 PM
Maybe a stupid question, but I gotta ask: When you guys are talking about cabinet volume, do you mean net of bracing and driver displacement?

If so, what are you using for the driver displacement?
:duck:
Charles

Mr. Widget
03-12-2004, 11:23 PM
Originally posted by John Y.


How, then, can the JBL 4641 or 4645C cabinets be tuned to 25 Hz (as they claim) with an (approx) 8" duct when the cabinet is less than 18" deep, unless they have a bend in the duct (which I doubt)? Yhese are 8 cu ft cabinets. Does cabinet size make that much difference?

Mr. Widget - I gather that measuring the resonant peaks is the best way of determining the system resonance, that is, resonance occurs half way between the peaks. That right? I like your idea of bottom duct placement being a good compromise, Now, if only I could find some JBL stilleto aluminum legs (circa 50's), I could have a real retro (looking) rig.

For an 8 cu ft box with an 8" duct, BBPro recommends a 19" port length for a 25Hz tuning. I would guess JBL is using an elbow. I have no practical knowledge of either of these systems so I can only speculate. (An 8" duct 13" long would achieve a tuning around 28Hz with typical fill. They may be gaining virtual volume and lowering the tuning with heavy fill.)

Yes, measure the lowest impedance between the two peaks. The absolute minimum should be at the tuning frequency.

Widget

PS. Chas, yes you subtract bracing, port volume, woofer and other driver volume, and make allowance for amount of and type of fill. (The fill part is kind of guess work, but BBPro gives 4 levels of fill and their "Typical" seems to match my style of fill.) As for woofer volume, I have a chart somewhere but can't find it at the moment.

Niklas Nord
03-13-2004, 02:02 AM
My K2 are using elbow-duct :p Så there canīt be anything
wrong with them... :)

4313B
03-13-2004, 06:40 AM
Originally posted by Chas
Maybe a stupid question, but I gotta ask: When you guys are talking about cabinet volume, do you mean net of bracing and driver displacement?

If so, what are you using for the driver displacement?
:duck:
Charles Actually it is a very good question. It's a good idea to determine what is being discussed, gross physical volume or net effective volume. The system is "looking" for a net effective volume and it is the builder's responsibility to take the gross physical volume, internal volume displacements (ports/ducts, subenclosures, bracing, drivers, etc.) and system losses (leaks, fiberfill, flexure, etc.) and create the required net effective volume. If you use fiberglass it will tend to negate the volume displacement of bracing, small subenclosures such as the LE5x/104x subenclosure, smaller port/ducts, smaller drivers, networks, etc. Volume displacements and system losses tend to cancel each other. In other words system losses increase effective volume while volume displacements decrease it. The better JBL enclosures generally measure total system loss at "10" or above. Software packages usually default to "7" which has always seemed to be considered typical. "3" is consider junk, worthless as a vented system.

The displacement rating for the 1500 SUB is 0.25 cubic feet. It has extremely low loss due to it's surround, cone, and dust cap construction.

"Yes, measure the lowest impedance between the two peaks. The absolute minimum should be at the tuning frequency."

The most accurate method is to measure the vented system and note the frequencies at which the two impedance peaks occur. For instance - a specific JBL L-96 has two peaks at 15.0 Hz and 54.0 Hz. Then seal the port and measure the single impedance peak and note it's frequency. In this instance it was 47.0 Hz. Fb will be the square root of (15.0^2 + 54.0^2 - 47.0^2) = 30.5 Hz.

In this instance the trough between the two impedance peaks occured at 30.0 Hz, which can definitely be considered "close enough". I believe D.B. Keele determined that Fb can vary by up to 10% without becoming a "problem".

Chas
03-13-2004, 09:11 AM
Thanks guys. I notice mention of BBpro, is this software that allows plugging in T/S parameters and trying different ideas to achieve lowest F3? Sounds like fun, about twenty years ago I had to do it the hard way from Thiele and Small AES reprints. I shudder at the thought of doing that again with my sub 1500's.

If it is software, where can I source it? Is it reasonably priced?
TIA,
Charles.

4313B
03-13-2004, 09:19 AM
"about twenty years ago I had to do it the hard way from Thiele and Small AES reprints. I shudder at the thought of doing that again with my sub 1500's."

I simply refuse to do so :rotfl:


You can get BassBox 6 Pro or BassBox Lite from Parts Express.

You can try Unibox from here:

http://home20.inet.tele.dk/kou/ubmodel.html

and WinISD from here:

http://www.linearteam.dk/

johnaec
03-13-2004, 09:39 AM
How do these newer enclosure programs compare with JBL's SpeakerShop 1.0 from the mid 90s? Harris Technologies produced JBL's version, but it appears to no longer be available. I picked up a version on the web some time ago, and it makes dealing with the T/S parameters really easy, asuming the math in the program is correct. I'm just wondering if anything new involving T/S parameters has been incorporated into the newer versions that might be missing from the JBL version?

John

4313B
03-13-2004, 09:43 AM
BassBox 6 Pro is from Harris Technologies. You can look on their site for revision changes. The errors in some of the published TS parameters of various JBL drivers becomes readily apparent in BB6P. (Errors originating at JBL, not Harris Technologies)

James Nobel
03-15-2004, 02:42 AM
Hello JBLers,

This is my first post to the forum.

I just ordered two Sub 1500s from Parts Express a few days ago. The girl who took my order was named Amy. She was very nice. I hope she didn't notice how nervous I was. You see, I'll have to confess straightaway that I'm very frightened about confronting the raw power of those beasts. Will I even have the courage to open the shipping boxes when they arrive? My God....thoses things weigh as much as a child. I am not so sure I'm man enough to control them....Lord.....why did I have to order two of the devilish things? Last night I had a nightmare that when I opened the Parts Express boxes.....out leapt two raging pitbulls that devoured my wife as they barked and woofed and woofed at something like 115 db. I woke up screaming.

Ok, Yes, I'll admit it.....here and now in this public place....I do.....yes, I do crave the brutal and awesome savagery of massive, thrusting, Kevlar impregnated pulp laying waste to any and all who would enter my domain without protection.

So, I guess that's the truth of it, I am both afraid AND hungry for the spoils of sonic violence.

Please...please....please......don't judge me. My judgment will come later.

4313B
03-15-2004, 05:16 AM
"This is my first post to the forum."

Neato

mikebake
03-15-2004, 06:17 AM
Originally posted by James Nobel

Ok, Yes, I'll admit it.....here and now in this public place....I do.....yes, I do crave the brutal and awesome savagery of massive, thrusting, Kevlar impregnated pulp laying waste to any and all who would enter my domain without protection.


Oh no, not another classical music lover...............................

Mr. Widget
03-15-2004, 07:14 AM
As a first time poster, you will be given the opportunity to borrow a pair of 1.5 cu ft sealed Sub 1500 test boxes. It is a Forum Member's benefit that we don't usually post publicly. If you are interested, just send me a Private message.

Well, OK so actually, I noticed that you are also in the SF area. I built a pair of these test boxes, and will be through with them shortly. If you would like to borrow them, let me know.

Widget

kenratboy
03-15-2004, 10:16 AM
Mr. Widget

WTF!!! 19? That is a LOT of money. Parts Express must love you!

I was going to order one of the woofers, but I don't have the tools (or money to buy all the good tools) to build a good box.

I guess I will just get a SVS!

Mr. Widget
03-15-2004, 10:59 AM
Originally posted by kenratboy
Mr. Widget

WTF!!! 19? That is a LOT of money. Parts Express must love you!



Yeah, they are inviting me to their company picnic this summer.:D


Widget

kenratboy
03-15-2004, 11:50 AM
"Yeah, thanks for comming! Just wanted to let you know we only paid $20 each for those things!!! You made us a bundle!!!"

maxwedge
03-15-2004, 12:05 PM
I just measured the Fc of my sub1500 using this, (http://www.danmarx.org/audioinnovation/impanalyzer.html) and it came out at 35Hz. The box is an old 3.0 cu ft Fisher box I sealed up and it's kind of cheep. Made out of 5/8" partical board with only 1 brace from front to back. I'm going to make a new sealed box with 2 SUB 1500's later (Don't have room for no more port's in my home!).:)

Question's..................
Will that Fc come down in a better box?
Has anyone measured the Fs of this driver yet and is it really at 25Hz? I haven't measured Fs yet and does the room effect this measurement? Is Fs better tested outside or is that getting a little extreme?

Scott

Chas
03-15-2004, 12:50 PM
Last night I had a nightmare that when I opened the Parts Express boxes.....out leapt two raging pitbulls that devoured my wife as they barked and woofed and woofed at something like 115 db. I woke up screaming.

Hmm...some of us might welcome the thought, lots cheaper than a divorce!
:D
Charles.

4313B
03-15-2004, 12:52 PM
"I just measured the Fc of my sub1500 using this, and it came out at 35Hz."

Ok, now use it to measure Fs. Suspend the driver from a joist so it's away from any surfaces. Try not to have any ambient noise as the diaphragm of the driver will merely pick it up too (It's a giant microphone). You can measure Qts, Qes, and Qms while you're at it :)

maxwedge
03-15-2004, 03:09 PM
OK, I'll hang it tomorrow and try Fs. Qts, Qes and Qms are beyond my current knowledge.:help: I've read about them but don't know how to measure them. Are they a mathematical result of Fs and Fc? How do I measure them?

Originally posted by Giskard
Ok, now use it to measure Fs. Suspend the driver from a joist so it's away from any surfaces. Try not to have any ambient noise as the diaphragm of the driver will merely pick it up too (It's a giant microphone). You can measure Qts, Qes, and Qms while you're at it

4313B
03-15-2004, 03:17 PM
Here (http://www.epanorama.net/documents/audio/speaker_parameters.html)

That's easier than me rambling on :D

jim henderson
03-15-2004, 03:23 PM
This is a great learning exercise http://sound.westhost.com/tsp.htm

4313B
03-15-2004, 03:40 PM
Yep, there you go! That's another way to fill a Sunday afternoon :p

maxwedge
03-15-2004, 03:57 PM
Ok, thanks.:p I'll let you know how it works out.:)

MJC
03-16-2004, 09:16 AM
Originally posted by Giskard
Yep, there you go! That's another way to fill a Sunday afternoon :p

I just jumped on the band wagon, ordered two of those beauties.
Now I'll have to build a couple of 4cuft cabs, and two new mirrored cabs for the two main L212s. So, along with the 2 112As I just sent off a m/o for I'll be all set with a 6 channel L212 ht backed with these 15" subs.:D

MJC
03-16-2004, 09:37 AM
Has anyone tried the PE 1000W SUBWOOFER AMPLIFIER? Would it be a good match for the sub1500? I haven't ordered any amps or crossovers for the two sub1500 I just ordered. I'll think about that after I get the boxes built.
I do have an old stereo amp I could use, but it only has 120wpc output.

Robh3606
03-16-2004, 10:19 AM
Hello MJC

How are you planning on setting them up?? How low do you want to go?? Flat or in an alignment where you need to EQ them?? If you EQ them with say 6db of boost that 120 watts will disappear right quick. You would loose 6db headroom. With room gain and such you may not have to boost them depending on your target lowend extension measured in your room. I would try the amp but be prepared to juice them up a bit depending on alignment and room gain/size and SPL level.

Rob:)

Mr. Widget
03-16-2004, 10:28 AM
I still haven't gotten it together to fully check out the sealed version with EQ, but in the ported 5 cu ft boxes (no EQ) I have clipped my 600+wpc amps. It was admittedly loud, but these things sound so good you want to air them out. I would recommend no less than 300-500 watts rms per woofer. I am not sure if those plate amps really deliver the goods.

Widget

BTW Playing a 20Hz warble tone through these is really stunning. Now, if I could only get those 16 additional boxes built.:D

pangea
03-16-2004, 11:41 AM
Originally posted by Mr. Widget

BTW Playing a 20Hz warble tone through these is really stunning. Now, if I could only get those 16 additional boxes built.:D

PERVERT!!! :p

BR
Roland

maxwedge
03-16-2004, 01:12 PM
Looks like this thing likes 21Hz in the open world:yes:. Like my hanging garden of JBL's :D ! So far I've only tested using this (http://www.danmarx.org/audioinnovation/impanalyzer.html) again, and made sure I calibrated it at every Hz around Fs....and sure enough, 21Hz is my highest reading. I'm giving it 10 volts at 21Hz now to see if it will go lower.:)

Yes Widget, I think you need big power for these....like about 500w or more each of clean power. I think I need a new amp also, lol.:(

jim henderson
03-16-2004, 01:23 PM
I've hung drivers like this in past also, but I read somewhere that the driver should be rigidly mounted, albeit far from any surfaces.

Also, I suspect the Fs will drop a bit when the driver gets broken in. Didn't Giskard recommend 10 volts/20Hz for several hours?

maxwedge
03-16-2004, 01:36 PM
Originally posted by jim henderson
I've hung drivers like this in past also, but I read somewhere that the driver should be rigidly mounted, albeit far from any surfaces.
It's all I can really do for now or in the near future. I'm a little new at testing speakers.:)

mikebake
03-16-2004, 01:36 PM
Anybody thinking about incorporating the sub1500 into a full range design?

Mr. Widget
03-16-2004, 02:21 PM
Originally posted by mikebake
Anybody thinking about incorporating the sub1500 into a full range design?

Hell no! I am selling all of my other speakers and only listening to bass now!:rotfl:

johnaec
03-16-2004, 02:33 PM
Originally posted by mikebake
Anybody thinking about incorporating the sub1500 into a full range design? I've been struggling with this exact thing. So far, besides the Sub 1500, I've got a pair of 10" 2012H, either 2404H or 077 for VHF, but am really undecided on upper-mids. I picked up a pair of 5" 2105H, (ala 4315B), but am also very interested in horn/driver suggestions instead. The 2430h and horn 2332 someone mentioned sounded like a possibility, but I haven't seen any definitive info on availability yet.

John

boputnam
03-16-2004, 02:59 PM
Originally posted by mikebake
Anybody thinking about incorporating the sub1500 into a full range design? I posed that very question to the Project May team a few weeks ago, but never got a reply. Makes sense to me - er, not that I didn't get the reply, but that it could be considered. I imagine it could mke a phenomenally interesting 4344X.

Oh well, back to my L100's... :slink:

boputnam
03-16-2004, 06:04 PM
Well, Widget just informed me that I'm ignorant of many things. Oh, and then we started talking about my knowledge of JBL... :rotfl:

mikebake
03-16-2004, 06:08 PM
Originally posted by boputnam
I posed that very question to the Project May team a few weeks ago, but never got a reply. Makes sense to me - er, not that I didn't get the reply, but that it could be considered. I imagine it could mke a phenomenally interesting 4344X.

Oh well, back to my L100's... :slink:

Any way you look at it, the sub1500 can create great, low distortion bass for a 15", in a smallish enclosure. I'm sure it bears consideration in a full-range design, where it could kick some serious booty. My thought was sub1500 to 10" to 2426 variant and horn to UHF device; nothing new or earth shattering, but just using a 15 that could really do some freaky bass!!!!!!!!!!!..............geez, we're only talking a 200 lb. speaker here!!!
MBB

MJC
03-17-2004, 05:46 AM
Originally posted by Robh3606
Hello MJC

How are you planning on setting them up?? How low do you want to go?? Flat or in an alignment where you need to EQ them?? If you EQ them with say 6db of boost that 120 watts will disappear right quick.
Rob:)

I have no doubt that the old amp is not enough, I'd only use it until I got a couple of plate amps or a high powered 2 channel amp.
I'm currently running two subs in a 3000+cuft room, with one at the mid point of a side wall and the other up front. They have a total of 400W.
I'm not sure what you mean by "in an alignment." I'm planning to make the boxes sealed w/o EQ.

JuniorJBL
03-17-2004, 07:14 AM
Originally posted by MJC
Has anyone tried the PE 1000W SUBWOOFER AMPLIFIER? Would it be a good match for the sub1500? I haven't ordered any amps or crossovers for the two sub1500 I just ordered. I'll think about that after I get the boxes built.
I do have an old stereo amp I could use, but it only has 120wpc output.

I use a Crown K2 which has 800wpc into 4 ohms. This amp can be had on ebay for about 6 to $700 allready broke in for you.

I have compared it to a few amps now and for the most part the K2 has better LFR than most amps at this price range.
Shane:D

johnaec
03-17-2004, 07:30 AM
These Sub 1500 speakers also caused me to go out and get another amp. I picked up a Crest CA-9 with 800 watts/channel @ 4 ohms.

The Sub 1500 has really caused me to drop a lot lately getting ready for future implementation. :bouncy:

The whole thing started with my appearance here looking for advice on what midbass speaker to use with a 2245H for live bass guitar. Then info on the Sub 1500 showed up, so I got one. :D Seeing how nice they are, I picked up two more to devote to HT. Then I thought, why not build a system around them? :idea: So I picked up two 2012H 10" speakers, got a pair of 4612OK off eBay for the 2404H HF, ('got the pair for less than two stand-alone 2404Hs), picked up a pair of 2105H 5" speakers to try for upper mids, then got a JBL DSC260A crossover/eq so I could tri-amp the whole thing. But that meant another amp - hence the CA-9, (I already had a Crest P3500 and P1501A). Oh yeah - I also picked up and E110 for mid-bass with the Sub 1500 for live bass guitar. Now all I have to do is build the cabinets... :hmm:

All because I just wanted to know if I should use an 8" or 10" speaker with the 2245H... :rolleyes:

John

David Dryden
03-17-2004, 09:18 AM
While we're on the subject of amplifiers, what d'ya guys think of the Crown PSA-2? I've seen a few on ePay lately, and they seem to have quite a bit of power. Decent amp?

pangea
03-17-2004, 10:16 AM
Originally posted by johnaec

... All because I just wanted to know if I should use an 8" or 10" speaker with the 2245H... :rolleyes:

John

Sorry about that... perhaps I should have kept my mouth shut... hmmm... but then again... most of y'all seem to have appreciated the info though. ;)

So, please don't come shooting the messenger. :duck:

BR
Roland

goskers
03-17-2004, 12:37 PM
week long reader, first time poster.

Hi all, just received my pair of 1500's yesterday. These things are very impressive.
Am trying to model a good enclosure to get a good response from 50 to 20 Hz. I am not finding anything that will do this. Can someone help? Should I just go with the 2cuft and eq it til quality desired?

On a different subject, I am looking for a pro amp that will push these properly but am worried about the fan noise. Are there any options out there besides the Crown K1 that won't cost an arm and leg?


wasser:cheers:

boputnam
03-17-2004, 08:04 PM
Originally posted by goskers
I ... am worried about ... fan noise. Dood! My band dies for that... :rotfl:

OK, sorry. I love to abuse syntax...

I have elsewhere here boasted about QSC's. Sure, they have cooling fans, but you don't notice them until the listening's over, and then, you can hear the Fridge, too... ;) The cooling fans are quiet. I think with the Wall Of Widget (stopped counting at 20 SUB1500's...) he too has at least three cooling fans, but they are largely inaudible - even between "selections".

I'm running the CX contractor series - 302's on the uppers, 502's on the bottom. No plans to change nuthin... :no:

So, being new here, you are way overdue posting some pics of your "rig" - we are voyeurs, all... :yes:

JuniorJBL
03-17-2004, 09:10 PM
Originally posted by goskers
Are there any options out there besides the Crown K1 that won't cost an arm and leg?


wasser:cheers:

I am curious as to why you do not want/like the "K" series amp?
I have compared this amp (K2) to many amps (including the Krell KAV series which is what I sold to get 2 K2's) and I have not found many amps below $1000.00 that even come close. My Adcom 555's sound very good but just dont have the bottom end like the crown's on both my L250's or my 1500's. But this is my own opinion.
Shane:D

MJC
03-18-2004, 07:46 AM
[QUOTE]Originally posted by Giskard
[B]What are you trying to accomplish?

The REVEL 15 takes twice the enclosure volume to go as low as the old 12" 121A/121H-based B212 Ultrabass. It will thoroughly spank the old B212 in pretty much every aspect while maintaining the same bandwidth. The B212 was a 2.0 cubic foot volume, the REVEL 15 requires a 4.0 cubic foot volume to accomplish the same bandwidth without EQ.


Giskard, having had a B212 for 25 years, I'd like to get the sub1500 to the same bandwidth. I think I'm going to get the PE 540W sub amp, which has full EQ. So do I still put the driver into a 4cuft box?
Along with the 2 subs I also ordered two 15", 1" thick baffles that are 19.75"sq. So the resulting cab will be 21"sq. face. The perimeter of the cab will be double 5/8" mdf, with the o/s layer running around the edges of the baffle. That gives me an 18.5"sq inside.

4313B
03-18-2004, 08:18 AM
If you're going to EQ, try something like a 2.0 or 2.5 cubic foot volume and add a few dB of EQ around 20 to 25 Hz. I don't imagine you will need very much. You're basically just trying to gain back the few dB loss down low the smaller volume will attenuate. I've tried this thing in a 2.6 cubic foot volume and a 4.0 cubic foot volume and frankly, I prefer the space savings. I didn't see any reason to add any EQ but that's just me. I'm still going to build that EQ doohicky from Rod Elliot just because it looks like fun :p

Be prepared to play with the low pass filter as the B212 filter is a bit different than usual. If I remember correctly it tends to flatten out the curve a bit and extends response. It is not EQ but rather careful bandwidth limiting. A B212 or 1500 SUB without that filter will appear to have greater energy in the 50 to 80 Hz range and less energy down in the 15 to 40 Hz range.

***

BTW - those are gross physical volumes I mentioned and not net effective volumes. If you have a B212 you know the gross physical volume is roughly 2.0 cu ft, the 121A/H sucks up roughly 0.15 cubic feet but all that fiberglass adds back a boatload of virtual volume so that the net effective volume is well over 2.0 cu ft. FWIW the 1500 SUB sucks up about 0.25 cu ft. Two inch thick fiberglass on all the panels except the baffle will effectively negate that volume displacement and any internal bracing volume displacement as well.

4313B
03-18-2004, 08:36 AM
"That gives me an 18.5"sq inside."

Well, just figure out the standing wave frequency of that dimension because it will be reinforced because it's square. Limit bandwidth accordingly. It's just a "signal to noise ratio" with the standing wave being the "noise"; attenuate it sufficiently with a low pass filter and it might be ok.

goskers
03-18-2004, 08:58 AM
I did not mean to imply that the Crown K's were not top of the heap. As far as I can tell they are! I would just like to find a viable option that is cheaper and quiet as well. I have heard the QSC name mentioned before. I would probably go with that.

thanks again guys,

I can post pics of my 'rig' next week sometime as I am pretty busy with school currently.

Joel

jim henderson
03-18-2004, 09:32 AM
Does anyone have a BassBox driver description file for this driver? It's not in the database.

JuniorJBL
03-18-2004, 09:39 AM
Originally posted by jim henderson
Does anyone have a BassBox driver description file for this driver? It's not in the database.

Bottom of page 2 of this thread is the numbers to use for making a file.
Shane:D