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Niklas Nord
04-19-2003, 05:57 AM
What is the 2234H ment for? Subbas applications?
Fast bass applications?

is it a well performing driver in that range between 50 to 280hz ?
better that 2235?

A friend of mine has put the 2235H in 375liters box and
ported to 21hz, and he says that he would not use it
ower 55hz..

im planning using 2235 in a subbas application, can i use
the 2234 in between 50 to 280hz then?

the difference between 2235 and 2234 ? weight? and then offcourse the FS...

im planning to use the massring on the 2235 to 17HZ

4313B
04-19-2003, 07:00 AM
"What is the 2234H ment for?"

It was specifically designed for the 4435 Studio Monitor

"Subbas applications?"

Yes, when used in multiples and tuned much lower than "normal" to take advantage of low frequency mutual coupling.

"is it a well performing driver in that range between 50 to 280hz ?"

It's performance is excellent

"better that 2235?"

Between 50 and 280, arguably yes.

"A friend of mine has put the 2235H in 375liters box and
ported to 21hz, and he says that he would not use it
ower 55hz.."

In his specific application that may be the requirement. The transducer itself certainly doesn't have that kind of limitation.

"im planning using 2235 in a subbas application, can i use
the 2234 in between 50 to 280hz then?"

Sure, but why when you can just duplicate the 4435 bottom end instead

"the difference between 2235 and 2234 ? weight? and then offcourse the FS..."

Yes, a 34 gram mass ring is the only difference between the two transducers. You can see the results of the mass ring by inspecting both transducer's TS parameters. The removal of the mass ring causes the Fs to shift up, Qts to shift down, reference efficiency to increase, usable frequency range to shift up, and high frequency response to become more ragged.

One very interesting listening comparison is the 2235H with its mass concentrated at the apex of the cone versus the LE14H-1 with its mass distributed evenly over the entire surface of the cone.

Bill Roberts
04-19-2003, 10:21 PM
I have always been pleased with the overall low frequency response of the 4435's. In a studio I worked, for 4 years, we had the Westlake BBSM10's in the control room and Tannoy PB6.5 as well as NS10's.

Main studio duty was JBL. 4412's and 4435's.

The Westlakes had a rather physical low end but mostly below 50hZ. Output in the range of 65 to 110hZ did not "connect" as the 4435's displayed. The 4435's in stock form were equally physical throughout the entire bass range, without the boomy bloat of the Westlakes. It seemed the reactance VS resistance in the room was very well matched. I feel it is a great design in the stock approved enclosures. Very powerful and musical.

Niklas Nord
04-20-2003, 10:42 AM
Thank you Giskard!!
Then i maybe will recone the empty baskets to 2234
and have som fast bassdetail from 50 to 250hz ...

is there a 2234 recone ?
is there a 2235 recone ?

what about the massring, can i buy these separately ?
the 17FS massring for 2235 for example.

is there any massring available for the 2245 sub ? 17FS ?

4313B
04-20-2003, 01:01 PM
Hello,

The 2234H and 2235H use the C8R2235 recone kit. Just have your reconer leave out the mass ring and have him give it to you in case you ever decide to use it.

The mass ring is available separately.

The 2245H already has the mass ring installed.

-------------------------------------------------------------------------------------------------------------------------
Ooops, my fault; looking at the 2245H, all the mass is in the cone assembly via aquaplas. No mass ring in the 2245H!
-------------------------------------------------------------------------------------------------------------------------

neriks
04-20-2003, 03:24 PM
Originally posted by Giskard

...

The mass ring is available separately.

The 2245H already has the mass ring installed.

Giskard,

Do you know if there is a mass ring available for 2241H or 2242H?

4313B
04-20-2003, 05:47 PM
-------------------------------------------------------------------------------------------------------------------------
Ooops, my fault; looking at the 2245H, all the mass is in the cone assembly via aquaplas. No mass ring in the 2245H!
-------------------------------------------------------------------------------------------------------------------------

The 2241H and 2242H don't use mass rings and I couldn't say whether or not the 34 gram mass ring would fit. Installing it might impact Xmax or the suspensions might not be up to handling the added weight.

Brief inspection of the published TS parameters for both transducers doesn't really fire up any enthusiasm for additional weight. I don't have time right now to work out the mathematics of the added mass ring but if you are REALLY interested I could possibly do so in the next few days.

For VLF or "subwoofer" applications the 2242H works best in 8 to 10 cubic feet tuned to 25 Hz. A 25 Hz auxillary filter (Q = 2) is optional and can benefit a single 2242H. A 20 Hz high pass filter is recommended. When used in multiples the concept of mutual coupling makes properly placed 2242H's extremely effective, especially when bandwidth limited to below ~ 80 Hz, and a 25 Hz auxillary filter (Q=2) becomes superfluous.

Mr. Widget
04-20-2003, 09:38 PM
""Subbas applications?"

Yes, when used in multiples and tuned much lower than "normal" to take advantage of low frequency mutual coupling.

"is it a well performing driver in that range between 50 to 280hz ?"

It's performance is excellent

"better that 2235?"

Between 50 and 280, arguably yes."

Hi Giskard,

Isn't it true though to get the performance that JBL achieves from the dual 2234s in the 4435, they do some crossover gymnastics.

In the 4355 they use a pair of 2235s in parallel, but with the 4435 to get the higher sensitivity and better transient response of the lighter cone assemblies doesn't the crossover in the 4435 filter out one of the woofers early and tweak the signal they see?

Have you had an opportunity to compare the parallel 2235 to the twin 2234 in the 4435? I am curious as in my 4355 clone setup I get a very tight and deep bass. I can appreciate the theoretical advantage in the 4435. I would be interested in observations anyone might have who has had first hand experience with these two set ups.

Bill Roberts
04-20-2003, 11:33 PM
It has been a long time but if I remember correctly, one of the woofers in the 4435 is allowed to go higher than the other and both go all the way down. I remember one of them (listening up close) had a very low crossover point.

I could be mistaken, it has been a very long time since I used them regularly.

neriks
04-21-2003, 03:02 AM
Originally posted by Giskard

The 2241H and 2242H don't use mass rings and I couldn't say whether or not the 34 gram mass ring would fit. Installing it might impact Xmax or the suspensions might not be up to handling the added weight.

Brief inspection of the published TS parameters for both transducers doesn't really fire up any enthusiasm for additional weight. I don't have time right now to work out the mathematics of the added mass ring but if you are REALLY interested I could possibly do so in the next few days.

...


Giskard,

Thanks for a very informative answer!!! :) Using a mass ring in a transducer like the 2242H (or the 2241H) is something that I've been wondering about for quite some time. The reason to this is mainly out of curiosity ;) ...

I you feel that you have time to work out the mathematics I would be VERY grateful! Would a mass ring yield a better low-end response of the 2242H? What happens to the T/S parameters besides lowering the fs?

4313B
04-21-2003, 07:29 AM
Hi guys,

Yes, the 4435 does employ an 18 mH inductor on one of the 2234H's to attenuate signals above ~ 100 Hz. That's so the other 2234H matches the 2344A at the 1 kHz crossover frequency. One shouldn't have both transducers covering the same bandwidth going up that high. Plus the limited bandwidth of the other 2234H results in the required VLF response. I thought the plan here was to use the 2234H to ~ 300 Hz.

As for transient response, the 4435 is only marginally better because much of the "inherently better" transient character of the lighter moving mass of the 2234H is "killed off" by forcing it to go so low. Remember my post about the 2242H versus the 2245H. The 2242H will go as low as the 2245H but not with the same "punch" because forcing it to do so "kills off" much of it's inherently better transient character. Now, you pretty much have to A/B these things to get the picture because frankly, they all sound so very good and only an A/B will reveal the differences.

Yes, I've had the opportunity to compare the parallel 2235 to the parallel 2234 in the 4435, several times in fact. In my opinion the stock 4435 setup is slightly superior to the stock 4355 setup. Personally though I prefer a custom dual 2235H solution wherein each 2235H is in it's own 5.0 cubic foot volume tuned to ~ 28 Hz instead of the smaller volume of the 4355 tuned slightly higher. I find the slight bass hump of the stock 4355 around 30-32 Hz makes it harder to integrate into typical rooms than the 4435, which integrates very well with typical rooms. Many people like that slight bass hump in the stock 4355 though. I think the custom 2235H solution I just mentioned also integrates a bit better with the typical room.

If he bandwidth limits the 2234H from 50 to 280 it will inherently sound "better" than a 2235H covering the same specific range providing both transducers are optimally loaded and tuned. If greater efficiency is required in a slightly higher bandwidth then the 2234 is the ticket, if VLF extension is prefered then the 2235 is the ticket. There is no way an optimally loaded and tuned 2234 will produce deep bass as well as an optimally loaded and tuned 2235, it is physically impossible, conversely, there is no way an optimally loaded 2235 will exhibit the same efficiency and transient character as an optimally loaded 2234, it's physically impossible. Forcing a 2242 or 2234 to produce VLF in the same realm as the 2235 or 2245 will obviously "kill off" some of the former transducer's "inherently better" transient character. Can't have something for nothing.

That said, the 4435 LF and VLF response is "still" very impressive, despite it's "non-optimal" configuration. Take those same transducers and tune them ~ 10 Hz higher in slightly smaller volumes and they will smack you right out of the room with their incredible punch but that will kill off the VLF. Same thing with the 2242, tune it ~ 10 Hz higher than the stock 4645C and it will kick you around the room forthwith at the expense of VLF. The 4435 was built using existing parts thereby keeping costs down. It's almost a fluke that the 2234 can be made from the 2235 with the result being a very viable transducer. Not all transducers react so favorably. I just have a hard time getting excited about using a single 2235H for VLF and crossing over to a 2234H for midbass. I don't think it is a good use of two 15" transducers. I can see a 2245H for VLF going to a 2234H for midbass. I can see using dual 2234H for VLF and midbass ala 4435 and I can see dual 2235H for VLF and midbass ala 4355. I just can't see using a 2234H for midbass and a 2235H for VLF. Now maybe dual 2235's for VLF crossing over to a single 2234 for midbass, THAT could be exciting...

Anyway, just my view of the situation.

4313B
04-21-2003, 08:56 AM
Hello neriks,

Installing the 51629 mass ring in the 2242H will result in the following TS shifts:

Fs will drop from 35 Hz to ~ 31.75 Hz. Qms will increase from 5.0 to ~ 5.51. Qes will increase from 0.29 to ~ 0.32. Qts will increase from 0.28 to ~ 0.30. no will decrease from 4.0% to 2.73% resulting in an SPL drop from ~ 98.2 dB W/m to ~ 96.5 dB W/m. Mathematically, adding the mass ring looks to be a reasonably viable endeavor.

A 2242H in the 4645C enclosure with the mass ring added will extend LF response from -3 dB at 35 Hz to -3 dB at 27 Hz. Group delay will increase a mere fraction of a ms. It should be noted that the drop in efficiency as specified above will only begin to occur above ~ 60 to 70 Hz in the 4645C enclosure.

Again, I have to stress that I have no idea if the 2242 will actually physically take the 51629 mass ring but careful removal of the dust cap and inspection should tell the tale. I'm fairly sure the suspension can handle the additional weight but would like to verify first before committing.

Mr. Widget
04-21-2003, 10:23 AM
Thanks for the overview of the 2235, 2234, 2242, 2245 woofers. This info falls in line with the theoretical and agrees with my practical experience.

I was under the impression that the 3135 was a bit more complicated in the low end, but it makes sense that simply rolling off the upper end of one driver would balance it.

As I was reading your post I was starting to think about a 2245 2234 combo myself. I guess most people go the 2226 route due to it's ability to take more power, but it would be very interesting to try.

neriks
04-21-2003, 10:27 AM
Giskard,

Thanks again for a very informative answer! Very kind of you ...

Based on your calculations I think it would be better to refrain from adding the mass ring to my 2242H's ;) ... I'm very pleased with the performance of my 2242H's as it is. One thing I've noted though, is that the sound becomes a little bit more accurate if I use a hi-pass filter to keep the frequencies below ~25Hz out of the 2242H's. I thought that the idea of using the mass ring could result in a better performance of the 2242H's under 25Hz. Perhaps it's better to use my 2245H's for this purpose, instead of tweaking my 2242H's? ;)

Once again, thanks for answering my questions :)

4313B
04-21-2003, 11:30 AM
Well I guess it all boils down to what you have on hand and what you want to accomplish. The 2226 shifts the bandwidth even higher than the 2234. I think if you want to cover 50 to 300 the 2234 is pretty hot. It definitely "fills in better" than the 2226 below ~100 Hz. The 2226 definitely handles the juice, especially above 80 Hz, and it really cranks out the SPLs. Personally, I really like the broader, flatter response of the older transducers for home but there is definitely a great argument for the lower distortion and power compression coupled with the tighter bandwidth and higher efficiency of the newer models. They are indeed SOTA.

In the end, it's probably not a good idea to attempt to retrofit the newer drivers into the older designs but to start from scratch instead and exploit the "different" bandwidths of the newer transducers if you're going to use them. I just love the LE14H-1, 2235H, and 2245H for VLF work in the home whereas I can't imagine using a 2245H in place of a 2242H in SR anymore. It just wouldn't happen. The older designs simply can't compete with the newer designs for dedicated SR work these days. In the home the older designs are still, to this day, more than capable of maintaining their venerable legacy.

The bottom line is, if someone is having a problem exploiting the potential of a 2235 or 2245 then they aren't using it properly. By design, there is nothing inherently "wrong" with the transducers. These aren't junk drivers. If someone is having a problem exploiting the potential of a 4645C with a 2242 or a 4648 with 2226's then they aren't using it properly. etc. etc.

Ian Mackenzie
04-22-2003, 04:34 AM
Giskard,

Your explanations of various woofer comos is very interesting.

Have you had any experience with the imaginary tuning concept featured in some of the new JBL Statement speaker?

Ian

4313B
04-22-2003, 10:21 AM
Ian, LOL :p

No comment ;) Or should I say "only in my vivid imagination"? :p

BTW what are comos?

4313B
08-31-2003, 05:15 PM
Originally posted by Giskard
Installing the 51629 mass ring in the 2242H will result in the following TS shifts:

.....

Mathematically, adding the mass ring looks to be a reasonably viable endeavor.

Yeah but after looking at it further it isn't. Don't add mass to the 2242H.
G.T. confirmed it would be a bad idea. They tried it and it wasn't all that great.

spkrman57
01-02-2007, 12:55 PM
Has anyone actually used a pair of 2235's in a 4648 cabinet tuned for best performance?

I have 4648 cabs and if it can be done without losing much VLF I would be spared getting cabinets built for sub duty(in the home environment).

I believe the 4648 is 7.99 cu ft per someones post in the past.

Please feel free to comment here on this!

Thanks, Ron

4313B
01-02-2007, 01:03 PM
Has anyone actually used a pair of 2235's in a 4868 cabinet tuned for best performance?

I have 4868 cabs and if it can be done without losing much VLF I would be spared getting cabinets built for sub duty(in the home environment).

I believe the 4868 is 7.99 cu ft per someones post in the past.

Please feel free to comment here on this!

Thanks, RonIf you have 4868's and 2235H's then you can bolt them together, tune them and tell us how it all works out! :) I'm sure 2234H's would work fine.

spkrman57
01-02-2007, 01:16 PM
Another option is to install (1) 2235 per 4648(I have a few of them).

With a single 2235 per 4648 I might try sealed and ported to hear the differences. With almost 8 cu ft per cabinet I will keep the power levels down.

With the dual 2235's per 4648, I am guessing the tuning will be slightly higher and power handling a little bit better. I am guessing the VLF extension with dual 2235's to be approx 5 hz higher than the optimum 2235 tuning in 5 cu ft cabs.

I hope to post some answers next week. I have to remove the (4) 4648's from their duty as a box spring/frame for my bed. I just did not have anywhere to store them lately.

Thanks, Ron

4313B
01-02-2007, 03:56 PM
I have to remove the (4) 4648's from their duty as a box spring/frame for my bed.Ok... now I know all you JBL guys are sick! Any doubt has been removed once and for all!:rotfl:
Thanks for sharing. :p

spkrman57
01-02-2007, 04:15 PM
According to WinIsd, (2) 2235's in 7.9 cu ft using only (1) port of 5" wide and 4.385" long would be approximately the tuning that would work best.

The 4648 cabinet uses (2) ports that size. I would close one of them with a pipe tester(Zilch type) and will measure the results.

The 4648 is approx 7.99 cu ft according to apost I read back sometime.

And yes, I will have to put my mattress on the floor to work on this project!:blink:

I will have a few empty 4648's available to JBL forum members if someone wants. I don't have the room for them all anymore.;)

Ron

4313B
01-02-2007, 04:48 PM
According to WinIsd, (2) 2235's in 7.9 cu ft using only (1) port of 5" wide and 4.385" long would be approximately the tuning that would work best.

The 4648 cabinet uses (2) ports that size. I would close one of them with a pipe tester(Zilch type) and will measure the results.

The 4648 is approx 7.99 cu ft according to apost I read back sometime.

And yes, I will have to put my mattress on the floor to work on this project!:blink:

I will have a few empty 4648's available to JBL forum members if someone wants. I don't have the room for them all anymore.;)

RonI might want one of them for an interim fix... :hmm:
Wait... I might want two temporarily. What say you?

spkrman57
01-02-2007, 05:45 PM
Thursday still look good?

I actually will be able to use the space if you borrow them for some time.

When they leave your place, I just hope to find a home for them with someone on the forum who can use them.

I'm tired of trying to get $$$ for everthing I own. Just make someone happy instead!

Just found out this last weekend that a friend of mine might sell me a pair(loaded with 2226J's) for a reasonable price. So I will have TOO many to keep anyways!

Ron

spkrman57
01-02-2007, 05:53 PM
http://audioheritage.org/vbulletin/showthread.php?t=1134&highlight=2235

I was reading to see how many different ways 2235's have been used by forum members. I was especially interested in seeing what a sealed cabinet would do.

After exhausting the searches(2235), I found only that using a 5 cu ft box sealed was not best.

If I went with that large sealed and did not gain anything compared to ported(at least that's the result I came up with), then using a 5 cu ft ported would be best end result.

So my search to use sealed cabs for the 2235 seems to be concluded with no good results.

I thought maybe the 4648's in sealed mode(single 2235 per cab) might have been persuable. After reading(eyes are tired now), I see that there is no benefit in that direction.

Ron

spkrman57
01-08-2007, 03:31 PM
Went and installed the pair of 2235H's in the 4648 cabinet today.

Tried playing with the ports before I go and buy Plumbers tester (5.25").

I see no need to buy them. I will go back to using a pair of L200 cabs and call it a day.

The results of my experiment can be described easily::(

BOOM BOOM BOOM

Nowhere near the finesse bass of the LE14H-1's, even when I used them in L55 cabinets(2 cu ft).

Experiment completed and done with.

Just goes to show that Winisd is not always correct with the sims!!!;)

Regards, Ron



If you have 4868's and 2235H's then you can bolt them together, tune them and tell us how it all works out! :) I'm sure 2234H's would work fine.

4313B
01-08-2007, 03:42 PM
I'm not terribly surprised. You need to use your WT2 to measure what Vb really is though.

grumpy
01-08-2007, 03:49 PM
Does appear that 2234's would do better in this case... I still have to put a set of similarly
sized boxes together to set up a 4435 bottom end, so I'd hate to see this thread go kaput.
Ron, did you actually try blocking one of the ports? Where did you set your upper cut off
(or did you run them wide-open?)

-grumpy

spkrman57
01-08-2007, 04:58 PM
Here is what I got with both 2235's installed and both ports open to start:

Fsb = 19.5hz
alpha = 3
Ha = 1.939
Fm = 37.8 hz

I did not test after stuffing the ports(poorly just to get indication of change)

One other bad thing I did was having the cabinet horizontal on the floor.:o:

I just gave up on this since I have a pair of L200 cabinets in the garage and I know it will be easier to work with.

Grumpy - I did stuff one of the ports, and then fitted a longer port in the remaining one. I think your 2234's will do just fine with retuning the ports!

Overall, I think the LE14H-1 just walks all over the 2235H's, but just my opinion though!;)

Regards, Ron

4313B
01-08-2007, 05:00 PM
Fm = Vb = 37.8 hz

That's about what I got with an impedance run in CLIO.

spkrman57
01-08-2007, 05:02 PM
I used parts express plate amp(good enough in the past for my purposes) and set the upper cutoff approx 10:00 on the 40hz to 160hz continuously variable control. I'm guessing around 80hz(?)

Ron



Does appear that 2234's would do better in this case... I still have to put a set of similarly
sized boxes together to set up a 4435 bottom end, so I'd hate to see this thread go kaput.
Ron, did you actually try blocking one of the ports? Where did you set your upper cut off
(or did you run them wide-open?)

-grumpy

spkrman57
01-08-2007, 05:06 PM
Fm = 37.8 hz

That's about what I got with an impedance run in CLIO with two 1500AL's
mounted.

For my use with 2235's, that figure means its tuned to 37.8hz, right?

After stuffing one port(wadded up foam - I know it's not perfect - just wanted to hear a change to help me think it out), I installed a slightly smaller ID port and longer. Helped, but not enough to work for me.

Ron

Robh3606
01-08-2007, 06:44 PM
Which PE plate amp do you have??? Is yours set for flat??? That's a 40Hz box and it will boom like hell with 2235's especially lying down. You need to tune it lower say 28-30Hz and stand it up. 2235's are punchy compared to Le14's, they don't need that much boundry reinforcement help. In the right box and tuning they can sound damn good. You really want them rolled off a bit depending on where you put them in your room. Like an extended bass alignment.

Rob:)

WTPRO
01-08-2007, 09:10 PM
Hi Ron
After measuring the driver and vented box tests, use the 'align vented box' button in the TS window to adjust the simulator to the in-box data. Basically this option iterates the simulator till a solution is found where the impedance peaks line up in frequency and amplitude. Its a lot easier and more accurate (IMO) than the old method. Be sure to use the Rem/Xem non linear inductance as well throughout for best results.

Keith

PS: Ive met a few LH members here at the CES. If anyone else is at CES, I am in the Venetian San Polo room 3502-3503-3504 booth 404.

Zilch
01-08-2007, 09:22 PM
Hi, Keith.

Be sure to go hear the new JBL flagship Everest II if you get a chance, and let the forum know what you think of it! :yes:

4313B
01-09-2007, 02:36 AM
Hi, Keith.

Be sure to go hear the new JBL flagship Everest II if you get a chance, and let the forum know what you think of it! :yes:I'm very surprised that you didn't go Zilch. I think it would be a great baseline for you. Providing, of course, that they ended up with a "good" room.

Its a lot easier and more accurate (IMO) than the old method.Thank you! :yes:

WTPRO
01-10-2007, 08:48 AM
If things slow down enough today I will try to find the JBL booth and have a look and listen of the Everest. But they dont seem to be listed as JBL. No problem, ... parent company name but I expect there will be multiple booths to hunt down!

Best regards
Keith

4313B
01-10-2007, 08:53 AM
Here you go Keith!

http://www.audioheritage.org/vbulletin/showpost.php?p=141466

mikebake
01-10-2007, 01:08 PM
When they leave your place, I just hope to find a home for them with someone on the forum who can use them.


Ron

I could probably use a few more! It's a good box, easy to use stock with 2226's. Not looking for VLF, but in their range, it's a useful box for me.

spkrman57
01-10-2007, 01:13 PM
Talk to Giskard as to what he will do with them when he is done.

I gave them to him to do with as he sees fit once he has finished with them.

Ron

4313B
02-01-2007, 08:03 PM
Right now both are loaded with dual 1500AL's which sound really nice.

spkrman57
02-02-2007, 02:36 PM
Right now both are loaded with dual 1500AL's which sound really nice.

I figure you had to re-port the 4648's for optimum performance!

Regards, Ron

4313B
02-02-2007, 02:40 PM
I figure you had to re-port the 4648's for optimum performance!I haven't had time to do much more than stuff one of the ports.