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nestawasright
10-08-2005, 12:22 PM
For those of us who would not take our antique JBL's on the Antique Road Show, here is one of us, needing to build a home stereo system from the JBL 4647 (Woofer) ; boxed and the 2245 (Horns) ; not boxed

I am very new to all this-a wanna be audiophile, with tons of love for great sounding music.

I plan on making these part of my home music system. I would love your input on what I want to do.

1. Suggestions on putting the 4647 in a home-hospitable box. It's present box will never be tolerated by my girlfriend. Never.
2. I would love to do the same for the 2245
3. Suggestions on Midranges that would complement these two.
4. Suggestions on other equipments; EQ, PREAMP and methods of connections that would bring the best out.

In short, you will help me, if you would be so kind, and with your knoweldge, build my first ever decent stereo system.
Thanks for reading. I will carefully read and fully consider ALL responses. I will post pictures up and, describing and listing all information about the system. We will all look at it as having a little part of us on it; the system.
Thanks again.
Michael.

Zilch
10-08-2005, 01:02 PM
http://www.jblproservice.com/pdf/Theatre%20Series/4647.pdf

Your woofer is either 2225H or 2226H, depending upon whether you have the "A" version of 4647. In either case, they (the woofers, themselves) don't have very much extended bass. Well, none, actually....

2445 is a driver. We need to know what horn it's on. A pic will tell us, if you don't know.

4647 cabinet can be finished nicely with a custom inset grille (using JBL Monitor Blue grille cloth, of course ;) ). They are very sturdily constructed, as you no doubt know from moving them, with extra-thick front baffles, well worth using.

Then, box the HF section in a similar-dimensioned box to sit on top, with an inset separator creating a reveal, like Altec 19, I think it is. Also, see pic below for the general two-piece concept.

You're probably going to be O.K. without a midrange. You need to be thinking tweeter and subwoofer, instead.

Me? I'd invert the 4647's and cut PT-F waveguides into them, then set them up on short stands and tell the GF they are "Bookshelf" speakers you've creatively adapted for floor use. See my avatar.

Depending upon what horns you have, you may be able to cut them into the 4647 boxes, actually.

Also, in another thread, your system is apparently for sale on eBay if you want another pair to work with:

http://audioheritage.org/vbulletin/showthread.php?t=7465

Please enable location display in your profile so we know where you are. Click "User CP," above, to do it....

Who's gotta pic of the Altec I'm referring to, please?

nestawasright
10-08-2005, 02:20 PM
Thanks a lot for that Z.

I would soon, very soon, go get a digital camera or borrow one and have the pics up here.

I may not need to, if this added information helps out. These are pulled from the backs of the speakers.

JBL
4647
Serial
12995A

JBL
2445 J
16 Holmes
Serial
100575

Would you please point me to where I could get this: "inset grille (using JBL Monitor Blue grille cloth".

I am simply amazed on first, how you thought of inversing your 4647s and how in the world did you accomplish the task. You may send me detail instrucions, if you will to my E-mail or here. What is "a PT-F waveguides".

Any suggestions on gear that would complement these. Also suggestions on Subwoofers and Tweeter. Thanks for the link on Ebay.

Zilch
10-08-2005, 03:13 PM
Is it 4673 system with 3115A crossover?

If so, you have a VERY nice two-way system there.

http://www.jblpro.com/pub/obsolete/Theater_Systems1.pdf

http://www.jblpro.com/pub/components/2445J.pdf

http://www.jblpro.com/pages/pub/components/2380a.pdf

http://www.jblpro.com/pub/obsolete/2225hj.pdf

http://www.jblpro.com/pages/pub/obsolete/3105-3115A.pdf

http://www.jblpro.com/pub/obsolete/Low_Frequency_Enclosures1.pdf

Zilch
10-08-2005, 03:59 PM
Would you please point me to where I could get this: "inset grille (using JBL Monitor Blue grille cloth".The objective is to make these "presentable" as furnishings.

Your front baffles are recessed about 1/2", no?

Measure for dimensions inside the recess.

Go to your local window glass shop and have them make a pair of rectangular window screens about 1/8" smaller all around than the recess, i.e., 1/4" smaller in each dimension. $40 max.

Purchase enough grille cloth to cover them and install. I only said "JBL Monitor Blue" because I sell it. Get whatever color you prefer.

Alternatively, forum member Sonofagun has some 1/4" thick acoustically transparent foam you could stick onto the screen with spray adhesive. He'll likely paint it any color you like, if you ask him.

Buy self-adhesive Velco mounting squares at the hardware store, and mount to the cabinet and the backs of the screens at the four corners.

Install your new grilles, pour a cool one, put on your favorite music, and think about whether or not you really have to refinish the cabinets after all.... ;)

[Note: Grille removal tool is an unbent big paper clip.]

Zilch
10-09-2005, 10:45 PM
Better?

Put a footing under them, and those cabinets are keepers.... ;)

nestawasright
10-09-2005, 11:15 PM
Actually, while we are on presentation, I have been entertaining the possibility of finding some good oak to build another cabinet for both set. I had plan on giving the cabinets a fine finish. And also, I was thinking of building cabinets that would be more "hospitable" in a living room. Since you say these cabinets are keepers, would you suggest on ways I could finish them? If you think of ways I could build the ones I talked about, that would be great as well. Would you happen to know the specifications for building cabinets for the horns? Still working on getting those pictures. Surely, they will be up before the end of this week. Thanks for your pics. I'm afraid the blue is a bit, well, I don't think the GF will go for it. Any other colors you have? I won't mind buying them from you.



Better?

Put a footing under them, and those cabinets are keepers.... ;)

Zilch
10-09-2005, 11:37 PM
Those are Sonofagun's foam grilles I mocked up for you there. They're a darker, more "royal" blue than the camera flash represents. He can make them in a variety of colors.

My point with the cabinets is it's unlikely you will be able to build, or have built, any better performing cabinets than you already have. Talk to your cabinet maker about veneering them in the wood of your choice, a footing under them, and a solid wood moulding around the front to match.

If you're thinking of solid hardwood cabinets, that's a BAD idea for speakers. MDF is the material of choice.

Also, talk to him about building new boxes in the same style for the horns to sit on top. There are no acoustic requirements of consequence, as the horn and driver are sealed. I'd recommend making them of 3/4" MDF with veneer, though, so that they are substantial.

As example, here's how L200's, actual home of those grilles, are finished:

Cyclotronguy
10-10-2005, 09:48 AM
Zilch,

You attached images of John Tucker's "Exemplar" did you need details on that system? Sonic impressions?

Cyclotronguy

Zilch
10-10-2005, 10:08 AM
I posted it mainly to illustrate that two-box systems can be made quite attractive looking, but I'd enjoy knowing more about the details of that particular system and its performance.

I'm basically a reflex bass guy, but I love reading about and seeing horns, too. I think the Kleinhorn, which I believe you worked on, is a real kick, for example!

Some of those horns are real "No fear" projects.... :D

louped garouv
10-10-2005, 10:26 AM
Who's gotta pic of the Altec I'm referring to, please?

how about this one.... complete with the lovely (and approving) spousal unit representation....

I like the looks of the Exemplar, has anyone hear heard them? Love my A7s...

think I may be selling my Model 19s -- a pair on ebay closed at over 2Gs recently..... :D

louped garouv
10-10-2005, 10:30 AM
how about this one.... complete with the lovely (and approving) spousal unit representation....



and in the test chamber....

along with another Exemplar pic....

Zilch
10-10-2005, 11:49 AM
"Spousal unit."

:D

nestawasright
10-12-2005, 02:48 PM
"Spousal unit."

:D

Hi Zilch,
You're right on the ball. louped garouv's setup there is the kind a spouse/GF would tolerate. I love the wine/dark red tone (as in clour, for I've not been fortunate to be invited to see, feel, and hear his system-too young here, me thinks) Anywho! I love the tone and that's the color, it's the kind that I'm heading for.

Can someone please tell me, except if Zilch has and I missed it (By the way, Zilch, I have a text file of every suggestion and help you've provided thus far), the advantages to having the driver recessed back into the cabinet and the method of doing so. It's pretty cool, but for presentation sake and to allow my cabinets (pictures of which I'm still working on to be posted here, to be allowed in the apt/house) I may have to put the cloth that Zilch-again-bless him-has suggested :applaud: Thanks to all who've inputed on the project here titled "New Project with JBL's 4647 and 2445". Work at this stage, mainly research, continues.

Looking forward to a whole lot more help and also, suggestions on equipments; Amp, Pre-Amp, EQ's, Midrage, Tweeter, that would complement these speakers.

Zilch suggested White's 4400, among other things. I just missed one on Ebay. Not bad since I've learnt since that I would need two of them not just one.
Thanks all!
P.S It was so nice to see an E-mail from this group wishing me happy birthday on Sunday. This relationship will last :bouncy:

louped garouv
10-12-2005, 02:51 PM
I wish that were my system... they are teh exemplar like my avatar -- maybe I will try to build some day, but

Right now I am running Model 19s and A7s (802G/511 & 515B Loaded)...



I also highly recommend the 4400s -- great (and possibly cheap) EQs....

Zilch
10-12-2005, 03:20 PM
Can someone please tell me the advantages to having the driver recessed back into the cabinet and the method of doing so.Those are bass horns, an entirely different technology. You have duct-tuned bass reflex low frequency cabinets.

nestawasright
10-23-2005, 09:47 AM
Hello all. I have ,for a while now, promised to have the pictures of the speakers on which this project is based. I now have them ready and are now here.
See them and post your suggestions on the project.

I am also going to post the horns in the "swap" pages. I am inviting proposals for their replacement. Interested in seeing specs on midrange and tweeters.

Accepting suggestions on Amp's, EQ's, Pre-Amp's and Crossover's that would compliment the 4647 here.

Here is the 4647:



Here are the horns:

Zilch
10-23-2005, 12:26 PM
It seems you are committed to replacing the 2445 drivers and 2380 horns.

Do you have the 3115A crossovers that came with that system?

Have you ever even played them?

Watch for updates to the "Quick and Dirty 4430's" thread.

I'm makin' two-ways outta them boxes over there in the next month or so....

nestawasright
10-23-2005, 02:14 PM
Hi Zilch,the ever so efficient board member-No I don't have the 3115A crossover that came with this system. I would have love to hear them.

I will keep my eyes peeled on your project as suggested. I expect to learn a lot from it, sonically and asthetically.

I'm not doing anything else with the 2445 drivers and cabinets. As per your earlier suggestion. I will work on the cabinet to make it more asthetically pleasing. I plan though, in replacing the horns, to get a midrange and set of tweeters. If I get just the drivers, I will build a cabinet to house both and set it on top the 4647 with its 2445 drivers. The proceed to get the rest of the equipments. Or, I would wait and see what your "two-ways" end up as and pick from that.

I have decided to trade in the 2380 horns because I cannot find an acceptable solution to bringing them in the living room. Rather, I would have to do a lot of GF bribing to do so. And I'm told to really enjoy them, I would have to be 30 feet from them. I cannot afford a house that size and certainly, an apartment is out of the question.

Thanks a lot Zilch. You've been most helpful. Keep the ideas streaming in!

Zilch
10-23-2005, 02:29 PM
Is this your horn? Check the dimensions.

http://www.jblpro.com/pages/pub/components/2380a.pdf

If so, the 30 ft. thing is total BS.

The 90 x 40 dispersion pattern is cited by JBL as optimum for home use.

AND, it plays down to 500 Hz, highly desireable.

Buy 3115A crossovers on eBay and try the system. If you hate it, you can always sell the components later.

http://cgi.ebay.com/JBL-CROSSOVER-MODEL-3115A-PAIR-GREAT-CONDITION_W0QQitemZ5821227815QQcategoryZ3284QQssPa geNameZWDVWQQrdZ1QQcmdZViewItem

nestawasright
10-24-2005, 02:34 PM
Zilch our abled and responsive board member is a "two-way" person. He has carefully and wisely nudge me to that approach. Where I sought to get a midrange speaker for this project, he has cautiously suggested I don't. "Try what you now have and see, before, I take it, spending money unnecessairly.
Question is, and this may be a foolish one from someone who's willing to learn--no how can I put this question. I cannot ask if two-way systems are better sonically than three way systems. But think I can ask, are two and three way systems particular to specific needs? Put differently, are two ways better for one application than another? Or is this just a matter of the components used and their capacity to satisfy the spectral length?
I hope to learn something from this, perhaps, dumb question. As I will be completing a two-way system with these speakers.
Michael

louped garouv
10-24-2005, 02:45 PM
A7s and Model 19s are both two way systems...

I like them both, think I am liking the A7s more than the Model 19s lately...

but two way systems can be good...

I also agree that the 90x40 dispertion is good for home listening -- I have both Altec 511 & 811 horns with that distribution, they sound fine (with proper dampning)

Zilch
10-24-2005, 03:05 PM
Put differently, are two ways better for one application than another? Or is this just a matter of the components used and their capacity to satisfy the spectral length?That's a VERY important question, actually.

The more drivers there are in a system, the more difficult it is to get them to integrate with one another. The ideal system would have but one driver, and it would cover the entire audio spectrum. It doesn't exist in practice, of course, largely because of the laws of physics in sound reproduction.

Recognizing this, I believe everyone would agree that two-way is the next reasonable choice, and a worthy pursuit. Because of the same limitations of technology, however, it's not easily achieved. There are compromises that must be made in putting together a good sounding system with just two drivers.

Getting full high-frequency extension is one of the problems. The simple answer is to add a tweeter on top of a competent two-way, and some would argue, since the tweeter is "supplemental," it's still a two-way system. That's a stretch, I'd say. On the other hand, using a sub at the other end IS, in my mind, merely an enhancement of a two-way system.

To most accurately reproduce the entire audio spectrum, more drivers, four or even five, often, are required. There are many advocates of such multi-way systems here, and they dedicate themselves to overcoming the difficulties of having the multiple drivers play together accurately and cohesively. Many threads in this forum document that endeavor.

Your system is a competent two-way. I am encouraging you to acquire the proper crossover for it and to see if you like the way it sounds. You may have to do some reconditioning of the drivers, as well.

I have no experience with your horn and mid/high driver, but considering what the system was designed for, I assume it's worth keeping together. I suspect there are other members here who know the 2445 and 2380/A well. They can better advise you on achieving optimum performance with that particular combination.

I DO know the 2225/6H in that box, and you'll likely find you'll want to add a subwoofer to your system for best performance, or replace the woofer and retune the box as I'll be describing in the Q&D thread. 2226H will not provide extended bass, but that which it DOES provide is highly accurate and articulate. Read punchy and dynamic here.

Bottom line, know what you have first before proceeding. Get the proper crossover, and play it for a couple of months. Who CARES what it looks like for now? That is easily remedied, once you determine it is worthy of the effort. As you say, the MUSIC is the prime consideration here, and THAT is yet to be experienced....

Zilch
10-24-2005, 03:44 PM
so my A7s with a 'supplementary' pair of 075 and 'additional' woofers = two way??? I had always heard my Xover referred to as a 4 way :blink:I agree, if you add a tweeter, you've got a three way, but to some, it's just semantics. Is it a two-way with add-ons? Is the crossover REALLY configured to integrate the system together, or are the subs and tweeters, in practice "supplemental?"

Is 4435 two-way, three-way, or quasi-four-way, actually? JBL has taken to using "quasi-" somewhat liberally in their marketing of late....

I think the point I'm trying to make is more fundamental. Nesta's system has a horn/driver combination that crosses at 500 Hz. If it actually works down there, and I have no reason to doubt that it does, that's highly desireable in a two-way system. Pushing 15" woofers to play up to 1 kHz is a major compromise, just as major as pushing the mid/high driver to play 20 kHz. That's 5+ octaves, tough duty.

I'm guessing this is a highly competent and desireable two-way. If it needs a bit of enhancement, that's an easy and relatively inexpensive task. If the two-way core is solid, don't abandon it, is all....

louped garouv
10-24-2005, 03:55 PM
Is the crossover REALLY configured to integrate the system together, or are the subs and tweeters, in practice "supplemental?"


I'm guessing this is a highly competent and desireable two-way. If it needs a bit of enhancement, that's an easy and relatively inexpensive task. If the two-way core is solid, don't abandon it, is all....

sorry I deleted my post for all of you wondering -- didn't want to get too OT...

in my case I would say the the intent is a four way, abliet with some unconventional design parameters -- my Xover is designed to provide a more exciting, lively reproduction -- I am not necessarily looking for lab flat response in my basement.... think Disco... (good disco, please)


point taken on teh starting block theory, that is the cheapest easiest way IME

grumpy
10-24-2005, 03:59 PM
I'd suggest pushing the cab's as close to the wall as possible. It really helps reinforce
the low end with this driver/cabinet combo...not into sub-territory, but it makes a
very perceptible difference, vs. several inches away from the wall or angled in, that
you may (or may not) find to your liking.

I'll have to get a mic designed for RTA before shooting my mouth off (subjective
comments) again re swapping 2446 diaphragms for the 2445's with the same horns
and 3115A's. Don't hold your breath, but it's on my list :bouncy:

-grumpy

Zilch
10-24-2005, 05:33 PM
Tell us how the system sounds to you, please, Grumpy.

Do you have 2225 and 2380 or 2226 and 2380A?

Do we know the difference(s) between 2380 and 2380A?

grumpy
10-24-2005, 09:24 PM
It's the more (relatively) recent cinema system with the
2226H/2445J/3115A complement.

2380 vs 2380A? appears to be limited to additional gusseting of the
horn in areas that were likely prone to failure (these are some heavy-ass
compression drivers). I'll try to take some photos
of the whole mess + the 2380(A) horns. I didn't go through the throats
with inside calipers to compare, but they appear to be the same.

Attenuation is maxed out (level matching between horn and direct
radiator), HF emphasis (CD boost) is set to maximum, horn wiring phase is
reversed (per system spec... interesting the the Perkins cab config isn't
also...phase must be rotated enough + time alignment for that to work
better).

Sound is very 'flat' sounding (no reference to imaging, which is OK), but
a bit bright with bass on the thin end... until you turn it up, then it starts
filling in. No obvious 'holes' or standout peaks in the intended passband.
Would like to be able to back these statements up with measurements.

Should mention that these are in a living room with a 2-story cathedral
ceiling with a rather open floorplan, so my comments about the "sound"
may not translate well to a different environment.

Opinion? No surprise here... They need a sub for full range duty. (Anyone
with blank 18dB/oct or 80Hz 523(4|5) cards?)

Comment:JBL/UREI 6260 amp is more than enough to part your hair with
these in a domestic setting (Yes, I have the obligatory Rat Shack SPL
meter, but that's about it other than warble tones on CD and my ears).

Other considerations:
9' apart, against the wall, both cab and horn straight out (no toe in)
(tried toe-in first, more "presence" but for extended listening, my
preference was no toe-in).

listening ~12feet from wall

rear wall - another 20' back, very uneven & open to other space.
side walls - 8' left of left speaker, more that 8' to the right

have not tried room eq with these speakers yet.

Zilch
10-24-2005, 10:01 PM
Sound is very 'flat' sounding (no reference to imaging, which is OK), but a bit bright with bass on the thin end... until you turn it up, then it starts filling in.

Comment:JBL/UREI 6260 amp is more than enough to part your hair with these in a domestic setting (Yes, I have the obligatory Rat Shack SPL meter, but that's about it other than warble tones on CD and my ears)..Thanks, Grumpy!

I have a 3 dB resistor L-Pad I usually also end up using on the HF with 311XA crossovers. Flat is too "bright" for me, too.

It's a pain to do, but Radio Shack SPL meters will generate response curves from a tone disk. Instructions in the manual.

Bought cheap 5233's just to get the 80 Hz cards. I'll watch for more to show up for you....

grumpy
10-25-2005, 07:04 AM
Bought cheap 5233's just to get the 80 Hz cards. I'll watch for more to show up for you....

Much appreciated.

nestawasright
10-25-2005, 04:59 PM
That's a VERY important question, actually.

The more drivers there are in a system, the more difficult it is to get them to integrate with one another. The ideal system would have but one driver, and it would cover the entire audio spectrum. It doesn't exist in practice, of course, largely because of the laws of physics in sound reproduction.

Recognizing this, I believe everyone would agree that two-way is the next reasonable choice, and a worthy pursuit. Because of the same limitations of technology, however, it's not easily achieved. There are compromises that must be made in putting together a good sounding system with just two drivers.

Getting full high-frequency extension is one of the problems. The simple answer is to add a tweeter on top of a competent two-way, and some would argue, since the tweeter is "supplemental," it's still a two-way system. That's a stretch, I'd say. On the other hand, using a sub at the other end IS, in my mind, merely an enhancement of a two-way system.

To most accurately reproduce the entire audio spectrum, more drivers, four or even five, often, are required. There are many advocates of such multi-way systems here, and they dedicate themselves to overcoming the difficulties of having the multiple drivers play together accurately and cohesively. Many threads in this forum document that endeavor.

Your system is a competent two-way. I am encouraging you to acquire the proper crossover for it and to see if you like the way it sounds. You may have to do some reconditioning of the drivers, as well.

I have no experience with your horn and mid/high driver, but considering what the system was designed for, I assume it's worth keeping together. I suspect there are other members here who know the 2445 and 2380/A well. They can better advise you on achieving optimum performance with that particular combination.

I DO know the 2225/6H in that box, and you'll likely find you'll want to add a subwoofer to your system for best performance, or replace the woofer and retune the box as I'll be describing in the Q&D thread. 2226H will not provide extended bass, but that which it DOES provide is highly accurate and articulate. Read punchy and dynamic here.

Bottom line, know what you have first before proceeding. Get the proper crossover, and play it for a couple of months. Who CARES what it looks like for now? That is easily remedied, once you determine it is worthy of the effort. As you say, the MUSIC is the prime consideration here, and THAT is yet to be experienced....

Zilch's point are well explained and noted. (If he ever wishes to teach, please make a go at it. Myself I relish the thought of spending a few weeks in your comapny) Zilch's answer however, in my young mind on this issue, raise some questions I hope the abled forum member might answer for the benefit of us all.

Does it not suffice that a crossover would deal with the eminent problems the presence of a lot of drivers would have on a system? All the drivers, from my understanding, reproduce particular output in the spectral length, and in areas where this reproduction overlaps, a crossover is brought in to redress that problem.

I accept that one driver would not and cannot reproduce the entire audio spectrum. However, may I point forum members to this fellow. Those who spend time designing cabs would find it of particular interest.
http://www.danleysoundlabs.com/DTS20.html

I struggle with the logic that because for scientific reasons we cannot have one driver that would produce the entire audio spectrum, therefore, we must subsequently settle for the next figure to one, which is two. The problem it seems to me is accurate representation and since a lot of drivers cannot do that, why could it be held then that two would or should?

The need to add a subwoofer to this system, which I would, for I take much of what Zilch says with much respect and read with close attention, shows that except if the drivers of any system is designed to reproduce most, since all can't be the case, of the audio spectrum, then there would always be the need for "supplemental" cabs on the system. The point here is one, is not possible, two is often found to be inadequate. Thus, where does that lead us? Does anyone here has a two ways system that reproduces at least 90% of the audio spectrum? Would they care to share?

Zilch pointed out, rightlyfully, that two-ways systems could be found to be lacking, ususally he says around the HF areas. This I assume is generally, because most drivers are made to produce mid to sub woofer frequencies, thus when you use them to create two-ways, it's almost only natural that you would need a tweeter or horn to compensate for the HF spectrum. Such is not the case on this particular system, as is well noted by Zilch. Thus, I would be looking for a sub-woofer. Please forward suggestions.

On from theory to more practical issues about this system. If I may ask some more questions.

Would anyone with particular knoweldge of the horns discussed here PLEASE pitch in with what they know. In particular, advise on achieving optimum performance with this particular combination. Please.

Zilch mentioned that I may need to "reconditioned" my drivers. This is my first time going pro on a home system. That naturally means I have never heard of "reconditioning" drivers. Any and all help would be GREATLY appreciated. Or how to recondition the cab.

Truly, the music is yet to be enjoyed. And that raises yet another question. I know there are equipements used to measure sound production from speakers. Would someone please say how this is done, and say why one must do such measurements? Are they really accurate, given that they measure one thing and the music, the song itself, is made to sound in another way-not sure if that makes sense written down.

Zilch is right, I will keep my eyes on that Q&D thread and proceed to set this system up and listen to it. I am still stuck on finding proper equipments that would compliment these drivers.

(P.S Please forgive all erros in spellings. Currently baby-sitting twins. Distractions abound!)

Zilch
10-26-2005, 06:04 PM
I'm workin' up a "tactful" response. ;)

duaneage
10-26-2005, 08:38 PM
I struggle with the logic that because for scientific reasons we cannot have one driver that would produce the entire audio spectrum, therefore, we must subsequently settle for the next figure to one, which is two. The problem it seems to me is accurate representation and since a lot of drivers cannot do that, why could it be held then that two would or should?


A 30 hz bass wave is about 60 feet long and a 15000 hz wave is about 1/2 inch. Frankly it is a miracle that 2 drivers can reproduce the range required let alone one. The real problem is directivity and at 1000 hx a 15 inch driver begins to "beam" it's output like a laser, instead of a wide pattern like a spotlight.

Dainty tweeter diaphrams are better than heavy cones at reproducing fast , high frequencies.

The need to add a subwoofer to this system, which I would, for I take much of what Zilch says with much respect and read with close attention, shows that except if the drivers of any system is designed to reproduce most, since all can't be the case, of the audio spectrum, then there would always be the need for "supplemental" cabs on the system. The point here is one, is not possible, two is often found to be inadequate. Thus, where does that lead us? Does anyone here has a two ways system that reproduces at least 90% of the audio spectrum? Would they care to share?

A smaller room reduces the need for driver area because the bass notes are reinforced by the walls. The more air in a room the more driver area for bass is required. As Mark Gander pointed out years ago, "You must move air to make noise"




Truly, the music is yet to be enjoyed. And that raises yet another question. I know there are equipements used to measure sound production from speakers. Would someone please say how this is done, and say why one must do such measurements? Are they really accurate, given that they measure one thing and the music, the song itself, is made to sound in another way-not sure if that makes sense written down.
Sound level meters are not too expensive and give an idea of what is going on. Other equipment like signal generators, voltmeters, impedance bridges, test discs, etc are necessary when your creating a speaker and do not yet know what the outcome will be.

having built a few dozen over the years I can tell you that some were sucessfull and some were not initially very good. If you follow Zilch's recommendations as well as others on this site you will probably be happy with the results.



(P.S Please forgive all erros in spellings. Currently baby-sitting twins.
Does this mean the budget is tight for massive audio projects?

Distractions abound!)[/QUOTE]

Mr. Widget
10-26-2005, 10:31 PM
"I struggle with the logic that because for scientific reasons we cannot have one driver that would produce the entire audio spectrum, therefore, we must subsequently settle for the next figure to one..."


The primary issue is with quality. You can take an 8" driver like the JBL LE8T and get it to reproduce the full spectrum with a bit of EQ, but it won't have the dynamics or ultimate SPL of a larger more sophisticated system. It will also have greater harmonic and intermodulation distortion as the high frequencies are being physically tortured by the bass notes... to a lesser extent this is true of two-ways also.

You need to decide what are the important issues for you and pursue a design that satisfies that goal. Don't forget room size which may also affect your decision... it isn't as simple as should I build a two-way or a ? The components that you mentioned at the beginning of this thread are not the easiest components to work with to create a home system. If you add a sub and a tweeter they can be outstanding, or you can sell them, get a pair of 2235Hs, and some 1" drivers and horns and follow Zilch down his 4430 path.

Personally I would love to build a two-way along the lines of the 4430 or K2-S9500, but I can't stand the compromises... the highs sound hard and the lower mids are just not as detailed or articulate as they are with a well designed four-way. There are issues with large four-ways too though and some prefer the simpler sound of a good two-way...

Good luck!

Widget

toddalin
10-27-2005, 09:42 AM
A 30 hz bass wave is about 60 feet long and a 15000 hz wave is about 1/2 inch.

Hate to be nitpicky, but please do the math before quoting misleading values.

speed = wavelength x frequency

Speed of sound at sea level is 1,116 ft/sec

1,116 ft/sec / 30 cycles/sec = 37 feet (not 60 feet)

1,116 ft/sec / 15,000 cycles/sec x 12 in/ ft = 0.9 inches (not 1/2 inch)

(Sorry, I write technical noise and air quality studies for a living.)

spkrman57
10-27-2005, 10:32 AM
wavelength(inches) = frequency / 13,500

I use this for aligning voice coils in a multiple driver system when vertical alignment of the voice coils is not possible.

I come up with 1.1" for 15khz

Not saying mine is right, just what I have used and it works fairly close for me.

Ron

Zilch
10-27-2005, 11:45 AM
http://www.drewdaniels.com/FREQ.pdf :)

jbl
10-28-2005, 05:17 PM
Zilch,
I have the exact system as the 4647 except that I bought the components separatly. The cabinet is the 4507. The woofer, the 2225H. I also thought about the style of the Altec 19 with the horn box sitting on top. Instead, I still don't know where I got the guts to do it, cut out the baffle to accept the 2370 horn. I took the 4671 OK catalog, it's the 4671 with the the horn installed into the cabinet and used the picture to scale where the cutout should be. The tricky part was to clear the wood brace which goes from the baffle to the rear of the cabinet. Cut too low or too high and you'll have enough fire wood for the winter.
Walnut venner and a plastic "glass" top, mitered front edges and a very nice looking system.
Don't underestimate the low end response. Room gain and or loss will determine your opinion. For me, the right side of the room extends the usable low end to around 33 Hz while room loss on the left side is noticable.
I stood on the right side (stronger side) and played the left channel with my tone generator. When I stand by the right speaker with only the left playing, the low bass is as strong as when the right speaker alone is playing. The room has a tremendious effect on the low friquency response.
With a good DC amplifier and preamp (Marantz 300DC and 3650) I never felt the need for a sub woofer. For me, a sub woofer would be in the range of an 8 ft3 cabinet with the 2245. Not enough real estate at the moment.

Ron

Zilch
10-28-2005, 05:43 PM
Cool, Ron: Do you have a pic or two for us? :bouncy:

Also, what'd you do for the UHF?

You're using 2425/6J on the 2370?

And which crossover? 3110A?

Zilch
10-28-2005, 10:57 PM
There's an entire discipline and a substantial literature of building speaker systems. Read through the Audio Engineering Society anthologies to develop familiarity with the complexity of the science involved. Colleges offer degrees in it, too. ;)

If one thing is clear in my experience in the Q&D project, it's that I can't just put any two drivers together with a crossover and expect them to work worth a whit as a system. The components interact with each other and the box that houses or mounts them in a complex fashion.

Two drivers is difficult. Add more, and the difficulties compound. All must complement each other in a very precise way for a successful outcome. It's VERY easy to fail at this. Zilch knows.

Thus, I (and others) look to the work and experience of the engineers at JBL for guidance, in the products they have produced, and in the literature they have published. I can virtually guarantee that your system was not assembled on a whim, and that's why I encourage you to complete it and give it a good listen in your environment according to your musical tastes as a baseline for any "improvements" you may subsequently wish to consider or accomplish.


Does it not suffice that a crossover would deal with the eminent problems the presence of a lot of drivers would have on a system? All the drivers, from my understanding, reproduce particular output in the spectral length, and in areas where this reproduction overlaps, a crossover is brought in to redress that problem.No crossover can compensate for the variables among drivers. Every one of them behaves differently, integrates differently with others, and has a different "voice," or sonic character. Even drivers with identical or similar T/S parameters sound different. Every driver combination requires a specific crossover for optimum performance.

There ARE, howerver, active sytem "controllers" at the leading edge of this technology that can compensate and balance many of the variables at once. They actually "listen" to the system performance to automatically optimize it. Nonetheless, the outcome cannot surpass what is possible with any particular chosen driver combination, which can still sound like poop.


I struggle with the logic that because for scientific reasons we cannot have one driver that would produce the entire audio spectrum, therefore, we must subsequently settle for the next figure to one, which is two. The problem it seems to me is accurate representation and since a lot of drivers cannot do that, why could it be held then that two would or should?No doubt, a well chosen assembly of multiple drivers can accurately reproduce the spectrum. Overcoming the complexity of getting them to work together to accomplish that is the problem. It's not, in my view, that a two-way can do it better, rather, that what it CAN do, is achieved with less difficulty, and thus, often, with greater success. If what you suppose could in fact be easily accomplished, none of us would be doing this.


The need to add a subwoofer to this system, which I would, for I take much of what Zilch says with much respect and read with close attention, shows that except if the drivers of any system is designed to reproduce most, since all can't be the case, of the audio spectrum, then there would always be the need for "supplemental" cabs on the system. The point here is one, is not possible, two is often found to be inadequate. Thus, where does that lead us? Does anyone here has a two ways system that reproduces at least 90% of the audio spectrum? Would they care to share?4430 comes mighty close, and that's why I have dedicated so much effort to it. There are tradeoffs in that design, however. Some would say the woofers you have reproduce a much more articulate, punchy mid-bass, and consider the 2235 in the 4430 to be sluggish and "tubby" by comparison.

Asking the same driver to concurrently reproduce the lower midrange from 500 Hz to 1 kHz is also a stretch, though earlier "vintage" designs relied upon high-mass cones and weaker motors for even higher frequencies. I think we now mostly agree those systems do not sound very good in comparison to better designs. The tradeoffs are better understood, now, and the design parameters as well.

Further, the 4430 incorporates HF "boost" circuitry in the crossover to force the compression driver/Biradial horn combination to reproduce frequencies near the limits of their capabilities. It's a delicate balance that just works, but to some tastes, the quality of that HF leaves something to be desired in comparison to that produced by a true UHF driver.

You'll have to listen to a pair of 4430's to decide for yourself how successfuly they accomplish the objective. I can confidently state, though, they are mighty good at it, and very pleasant listening.


Would anyone with particular knoweldge of the horns discussed here PLEASE pitch in with what they know. In particular, advise on achieving optimum performance with this particular combination. Please.2380 is a Biradial constant directivity horn, not unlike that used in 4430. Being a larger format, it will reproduce lower frequencies with competence, highly desireable since the woofer is no longer required to produce them. Your system crosses at 500 Hz, a BIG plus.

Also, it has a 90 (horizontal) x 50 (vertical) dispersion pattern, which JBL touts as optimum for home use, both for music and home theater. Read and learn about the specifications in the data sheet and the JBL Pro website technical library. I am just now beginning to work with the similar, next-generation 2352 horn. It's playing in the background here right now.


Truly, the music is yet to be enjoyed. And that raises yet another question. I know there are equipements used to measure sound production from speakers. Would someone please say how this is done, and say why one must do such measurements? Are they really accurate, given that they measure one thing and the music, the song itself, is made to sound in another way-not sure if that makes sense written down.I have plastered RTA (Real Time Analyzer) curves all over the forums since I first acquired the capability. The device plays full-spectrum pink noise through the complete system, and "listens" to the reproduction, displaying the response at the various frequencies, every 1/3 or 1/6 octave from 20 Hz to 20 kHz.

There are more sophisticated and more accurate ways to measure system performance, to be sure, but an inexpensive ($150 - $300) RTA provides substantial information instantly. I can tell you from my own experience that it is quite impossible for me to know what is going on with a sound system by ear alone. I cannot assess comparative system component performance, either, without, at minimum, an RTA.

It's certainly true that no measurement, or combination of measurements, for that matter, defines how the system sounds playing music. However, certain fundamentals regarding the frequency response must be in place or the system is GUARANTEED not to sound good. That's what an RTA measures, and I see many more forum members acquiring the capability to objectively evaluate and improve their sound systems using one.

johnaec
10-29-2005, 06:49 AM
2380 is a Biradial constant directivity horn, not unlike that used in 4430. Being a larger format, it will reproduce lower frequencies with competence, highly desireable since the woofer is no longer required to produce them. Your system crosses at 500 Hz, a BIG plus.

Also, it has a 90 (horizontal) x 50 (vertical) dispersion pattern, which JBL touts as optimum for home use, both for music and home theater. Read and learn about the specifications in the data sheet and the JBL Pro website technical library.Actually, the 2380 is spec'd as a 90 x 40 horn. And while the 2380 may provide full loading down to 500 hz, pushing either the 2445/2446 or 2380 down to 500hz is a real stretch - both are about 10db down at 500hz, and the power rating is also lowered down there.

Edit: I went back and looked at the specs, and the 2445/2446 actually do 500hz pretty well on a plane wave tube. It's with the 2380 that it's about 10db down at 500hz.

On another note - I just BIN'd a pair of 3110A's, (800hz), to try with my 2206H/2226H + 2446J/2380A/2385A combos...

John

jbl
10-29-2005, 09:14 AM
Cool, Ron: Do you have a pic or two for us? :bouncy:

Also, what'd you do for the UHF?

You're using 2425/6J on the 2370?

And which crossover? 3110A?
Hi Zilch,
Sorry, no pictures as of yet. I'll be getting a Digital Camera soon. Will post pictures.
I'm using the 2425 and 2370 for the HF response. A 2 way system. The HF response is very life like. Almost 3D! You can see the sharpe edges of the cymbal in your mind with the right recordings.
Yes. The crossover is the 3110A. Set to its MEDIUM position. The crossover is seamless between the 2225 and 2425.
Great sound!

Ron

Zilch
10-29-2005, 10:45 AM
Thank you, Ron. We'll watch for the pics!

I'm bettin' nestawasright has some good listening ahead once his system is operating properly.... :bouncy:

Zilch
10-29-2005, 10:48 AM
On another note - I just BIN'd a pair of 3110A's, (800hz), to try with my 2206H/2226H + 2446J/2380A/2385A combos....That sounds like a good option to try. 2225/2226 can play 800 Hz easily in that system, I'd think....

duaneage
10-30-2005, 06:34 PM
Hate to be nitpicky, but please do the math before quoting misleading values.

speed = wavelength x frequency

Speed of sound at sea level is 1,116 ft/sec

1,116 ft/sec / 30 cycles/sec = 37 feet (not 60 feet)

1,116 ft/sec / 15,000 cycles/sec x 12 in/ ft = 0.9 inches (not 1/2 inch)

(Sorry, I write technical noise and air quality studies for a living.)

wavelength(inches) = frequency / 13,500

I use this for aligning voice coils in a multiple driver system when vertical alignment of the voice coils is not possible.

I come up with 1.1" for 15khz

Not saying mine is right, just what I have used and it works fairly close for me.

Ron


Whatever.

Someone come up with the right exact formula and settle it.

My Point is still made.

jbl
10-31-2005, 07:11 AM
That sounds like a good option to try. 2225/2226 can play 800 Hz easily in that system, I'd think....
Seamless crossover. Fast attack and great bass awaits you.
Enjoy.
Ron

Zilch
11-03-2005, 10:02 AM
Rework these horn cabinets, maybe?

http://cgi.ebay.com/CABINETS-FOR-JBL-HORNS-AND-DRIVERS-2380s-SERIES-2445_W0QQitemZ7363265342QQcategoryZ47094QQrdZ1QQcm dZViewItem

nestawasright
11-04-2005, 02:27 PM
Rework these horn cabinets, maybe?

http://cgi.ebay.com/CABINETS-FOR-JBL-HORNS-AND-DRIVERS-2380s-SERIES-2445_W0QQitemZ7363265342QQcategoryZ47094QQrdZ1QQcm dZViewItem

Thanks a lot Zilch. I'm right on 'em. That was so considerate of you. Thanks a lot again-been busy lately.

From all the input thus far, I have decided now to begin looking for subs for this system. Primarily because I accept what most have said, and from my reading that the bass on the woofers need compliments.

Those who've seen these woofers or heard them before, would they please make suggestions on the subs.
Thanks.

nestawasright
11-08-2005, 03:15 PM
Rework these horn cabinets, maybe?

http://cgi.ebay.com/CABINETS-FOR-JBL-HORNS-AND-DRIVERS-2380s-SERIES-2445_W0QQitemZ7363265342QQcategoryZ47094QQrdZ1QQcm dZViewItem

Sent two sets of E-mails to this guy now about the size, etc of these cabs. No response. Maybe a good sign for me to pay heed.

I sent a PM to Ron today, maybe he will get those pics up for us soon.

I'm in the market for the 3115A crossovers (for the benefit of all) and also a pair of
2235H drivers.



Actually, what do people think of this: would getting a pair 'over-doing it' or would just one do the job? And it seems I would be needing another Amp to drive the one or two of these. Any recommendations for a power sub amp? Anyone, please. If you have these, what are you using them with? I thought if I'm going to get a 'em, I'd like something that is sonically 'warm'.



Now somehere here we thought we would go for the Altec look-with the introduction of these subwoofers, any ideas on what look we would now examine? Increasingling, it's looking to me as though the sub would not be cased together. That could be my young mind speaking. Ideas please...



I have decided to follow suit and follow Zilch to acquring the UltraCurve DEQ2496 ,except if I'm reasonably advised against it, for this system. One of my worries is that it will not compliment these antiques, though it seem to do for Zilch and others...

Zilch
11-08-2005, 04:50 PM
Sent two sets of E-mails to this guy now about the size, etc of these cabs. No response. Maybe a good sign for me to pay heed.For the kind of money it looks like those will go for, it don't look like there's much of a gamble....


I'm in the market for the 3115A crossovers (for the benefit of all) and also a pair of 2235H drivers.Yup, we're watchin' for those for you. If nothin' shows in the next month or so, we'll come up with some alternatives for you to consider.



Actually, what do people think of this: would getting a pair 'over-doing it' or would just one do the job? And it seems I would be needing another Amp to drive the one or two of these.Two's better so you can play them in stereo. Yes, you'll need another amp to run 'em, and a crossover unless your controller has a sub output on it. We'll have some recommendations for an economical (<$300) resolution of those matters.


BUT, it may be you'll be trying swappin' those 2235H's into your 2507's in lieu of the 2225H's there instead, when the time comes. Start lookin' for them now, in any case, or a thrashed pair of 2225H's you can have reconed to 2235H.


Now somehere here we thought we would go for the Altec look-with the introduction of these subwoofers, any ideas on what look we would now examine? Increasingling, it's looking to me as though the sub would not be cased together. That could be my young mind speaking. Ideas please.If you ultimately decide to add subwoofers, they'll be in separate cabinets. Box design instructions for B380 appear on the last page of this article:


http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm



I have decided to follow suit and follow Zilch to acquring the UltraCurve DEQ2496, except if I'm reasonably advised against it, for this system. One of my worries is that it will not compliment these antiques, though it seem to do for Zilch and others.It'll work fine with your system, but an RTA/digital equalizer is more like supplemental gear; it's not essential to gettin' your system up and running. I don't think I'd be getting one until everything was operational.

[I might be puttin' it on my Xmas list now, tho.... :p ]

jbl
11-09-2005, 08:30 AM
Sent two sets of E-mails to this guy now about the size, etc of these cabs. No response. Maybe a good sign for me to pay heed.



I'm in the market for the 3115A crossovers (for the benefit of all) and also a pair of
2235H drivers.








Actually, what do people think of this: would getting a pair 'over-doing it' or would just one do the job? And it seems I would be needing another Amp to drive the one or two of these. Any recommendations for a power sub amp? Anyone, please. If you have these, what are you using them with? I thought if I'm going to get a 'em, I'd like something that is sonically 'warm'.








Now somehere here we thought we would go for the Altec look-with the introduction of these subwoofers, any ideas on what look we would now examine? Increasingling, it's looking to me as though the sub would not be cased together. That could be my young mind speaking. Ideas please...








I have decided to follow suit and follow Zilch to acquring the UltraCurve DEQ2496 ,except if I'm reasonably advised against it, for this system. One of my worries is that it will not compliment these antiques, though it seem to do for Zilch and others...














I sent a PM to Ron today, maybe he will get those pics up for us soon.

Hi Mike,

At the moment I don't have a digital camera, sorry.
I'm using the 2425J compression drivers mounted in the 4507s. Your 2445s won't fit. The brace running from the baffle to the rear of the cabinet will prohibit this. You'll have to place the 2445 on top of the cabinet. I'll check today if I took any 35 mm photos of the speakers.
Ron

nestawasright
11-23-2005, 05:27 AM
how about this one.... complete with the lovely (and approving) spousal unit representation....

I like the looks of the Exemplar, has anyone hear heard them? Love my A7s...

think I may be selling my Model 19s -- a pair on ebay closed at over 2Gs recently..... :D

Has anyone seen or have access to the dimension specs to the Altec Lansing Model 19.

John
11-23-2005, 01:45 PM
Hi Post a email address or send one to me in a pm. I think I have a spec sheet for constructing a pair of 19,s Will try to find it. Someone sent it to me years ago and it seemed to be the real deal.

John
11-23-2005, 06:13 PM
I was looking at the picture of the horn, and it does not look like a 2380 to me at all? It does not even look like JBL?

johnaec
11-24-2005, 07:42 AM
I was looking at the picture of the horn, and it does not look like a 2380 to me at all? It does not even look like JBL?I agree - 'not a JBL. The 2380 has 3 mounting holes vertically, (not 2), with holes in the corners, and 4 holes horizontally, not 3.

John

Zilch
11-24-2005, 10:07 AM
Y'all are saying Nesta's horns are neither 2380 nor 2380A?

Looks like the 3115A's went for too much $$$.

Consider 3110A crossovers as a second option as discussed above....

louped garouv
11-24-2005, 10:22 PM
Has anyone seen or have access to the dimension specs to the Altec Lansing Model 19.



http://home.earthlink.net/~jmarkwart/index.html

check here... :D

nestawasright
11-25-2005, 05:34 AM
I agree - 'not a JBL. The 2380 has 3 mounting holes vertically, (not 2), with holes in the corners, and 4 holes horizontally, not 3.

John

John and Johnace I have no reason to say something IS what's it's NOT. Those horns, along with the rest of the system that started this thread were bought at University's summer/clear out sale. They have then been sitting at my friends garage coming to two years now. Myself, upon your comments about the 'holes', have gone back and counted them, against the pics of the 2380A picture I have, and yes, mine have two holes, NOT three. So, thanks to both of you for bringing this to our attention. We now have to figure out exactly what horns those are. I know they are JBL horns, that much I know for sure. Why? you ask. Since this is a university, I know that they would not have bought the horns and the drivers separately. They would have bought the whole system from a JBL distributor. I may be wrong, clearly, this is speculation. But I'll kiss the person's feet who would come up with the 'real' horns. I missed it, so thanks to the two 'John's' for bringing this to our attention. There is no question about the driver as the picture is very clear, so I suppose out first point of investigation is trying to determine exactly which horns JBL would have installed those drivers on. The first to solve this one gets a thumbs up! You saved me the frustration of building a project around an inaccurate system. Now we have to begin thinking of alternative to house the 2445J drivers (undisputed). I imagine looking for the horns will set the project even further as the 3115A crossover and the LF, or far LF, are presently doing. Ideas, Ideas!

johnaec
11-25-2005, 06:45 AM
There's also the possibility it's some kind of clone JBL horn, where they just moved the holes to avoid copyright infringement. It may be the acoustic equivalent of a 2380 in this case. Can you take some more pics and include some measurements? I'm sure we can get this figured out...

Also - 'looks like a nice set on eBay right now - they come up a lot, and usually seem to go for $150-$200 a pair in good shape: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7368520108&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

John

hwirt
11-25-2005, 08:54 AM
http://www.sengpielaudio.com/calculator-wavelength.htm

speakerdave
11-25-2005, 10:38 AM
Those horns may be a longer throw horn in JBL's 238X series.

David

Edit: No, you're right; the hole patterns are the same for the whole series. They appear to not be JBL horns.

Zilch
11-25-2005, 10:45 AM
How do we feel about using 3110A's as alternative crossover to 3115A, which seem to be a bit pricey at the moment?

John
11-25-2005, 10:53 AM
The jbl distributor could of used anything in that system, depending on what the customer wanted to spend? Every one has a budget even the U. of M. Those do not even look close to a 2380? Look into the throat it is compleatly different.

johnaec
11-25-2005, 11:30 AM
How do we feel about using 3110A's as alternative crossover to 3115A, which seem to be a bit pricey at the moment?I'm perfectly happy with the 800hz 3110A's and my 2446H/2380A/2206H, (soon to be 2226H), combination right now.

BTW, Zilch - I did rig up one of those padding filters you suggested, and balance seems to be much better. I haven't done any objective testing yet, though...

John

nestawasright
11-25-2005, 05:47 PM
There's also the possibility it's some kind of clone JBL horn, where they just moved the holes to avoid copyright infringement. It may be the acoustic equivalent of a 2380 in this case. Can you take some more pics and include some measurements? I'm sure we can get this figured out...

Also - 'looks like a nice set on eBay right now - they come up a lot, and usually seem to go for $150-$200 a pair in good shape: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7368520108&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

John

Yes, John I will try and get some more pictures up here. The only problem is I'm presently travelling, so I will ask a 'busy' friend of mine, who's hosting them in his garage now and see if he can take some more pics as well as get us the dimensions. Myself, I'd be very happy if we can figure this out.
I know that when I put those horns on top of the 4647 cabs, they go well beyond their depths. This was the reason, I was wondering just how the Altec 19 designs were going to work. But I trusted Zilch, and still do, for he was advising based on the assumption that I had what I thought I had. Anyway, the drivers are right, the horns are wrong. Now I have to solve this one, and then we continue where we left off. I'm going to spend the the weekend, in part, reading up on the 3115A alternative Zilch threw at us. My zest for everthing 'pure' on this project is now lost, once that 'detective' John has pointed out that the system is not as genuine as I'd thought. Oh! well, we all learn. Now we are going to make the best of it. Those who have seen the real horns and the 4647, do the horns hang on top of the cabs, or is the length on the cabs adequate?

Zilch
11-25-2005, 06:45 PM
PM Grumpy to post a pic, maybe. He's got 'em in his living room. :)

See also the data sheet early in this thread for 2380(A) dimensions.

Woofer box is 17.625" deep here. 2380A "Compact size" horn's only 9.28" deep without the driver. Driver's 5.188" deep, looks like. The assembly should not overhang.

Sounds like your friend is right about your horn, i.e., that you've got to be 40' back to listen. As Dave suggests, it looks like a long-throw setup, not the standard system. :(

O.K., we've got no crossovers, the wrong horns, and a LF system requiring subwoofer supplementation, all of which has to be repackaged.

Time to rethink this, maybe....

grumpy
11-26-2005, 03:25 PM
plenty of room front-to-rear. Bracket that came w/, puts front of horn in front of cab
by a few inches, but that's just how this pair was setup.

-grumpy

nestawasright
11-27-2005, 06:07 AM
plenty of room front-to-rear. Bracket that came w/, puts front of horn in front of cab
by a few inches, but that's just how this pair was setup.

-grumpy

Grumpy! thanks so much. You are the person with the right horns. The horns that I have run twice or even three times the length of the pictures you posted. Boy! how I love what your's look like. Now the trouble is to get rid of the ones I have. Any takers? Swap? (Ok, Ok, this is not the place for that-sorry) Anywho, thanks a lot Grumpy. It was like night and day. Your horns do not look anything like I have. I'm trying to get my bud to take the pictures, as I won't be by them not until Feb. Thanks a lot, what pretty horns! The drivers on them, are they the same as mine?

grumpy
11-27-2005, 06:28 PM
OK. I've never though of 2380A's as particularly 'pretty' (what was it someone
said the other day... "old, grumpy, and ugly" ?) :D, but yes:
if your drivers are 2445J's, then they are the same as in the photos I
uploaded.

I've a pair of 2380A horns that are almost as pretty (one missing the sticker
and is an early type w/o additional ribs on the backside, the other is newer
with a not very noticeable corner "repair"). If you eventually determine that
you need a pair that are not of museum quality, send me a PM and I'd be
happy to discuss terms.

-grumpy

jbl
12-05-2005, 10:19 AM
nestawasright, (Mike)
You have a PM.
Ron

Zilch
12-05-2005, 10:40 AM
O.K., we've got no crossovers, the wrong horns, and a LF system requiring subwoofer supplementation, all of which has to be repackaged.

Time to rethink this, maybe....
I've loaded 2235H's in 2507's and retuned them over in Q&D. Having heard these for two days now, I'd say the LF is done. No subs required.

Johnaec is loaning me a 2380A and 2445. I have 3110A crossovers for starters. We'll see how they play together soon.

Anybody have a spare pair of 2507's around? I want to cut PT waveguides into them. They are more substantially made and braced than L200's. Should be less resonances.

Watch for some for me, please....

johnaec
12-05-2005, 12:50 PM
Johnaec is loaning me a 2380A and 2445.Actually, it's a 2446, (though on paper, specs look the same...).

John

Zilch
12-05-2005, 01:10 PM
Actually, it's a 2446, (though on paper, specs look the same...)Would someone synthesize the difference(s) between 2445 and 2446 for us here, please? I know zilch about these drivers.... :(

Robh3606
12-05-2005, 02:17 PM
Phase Plug, 2446 has the newer Coherent Wave like the newer drivers

Rob:)

http://www.lansingheritage.org/images/jbl/specs/pro-comp/2446/page1.jpg

Zilch
12-15-2005, 04:37 PM
2446J/2380A on loan from Johnaec (new D16R2450 diaphragm) mates via 3110A crossover to 2235H in 2507 cabinet with two blocked ports. Plays fine "right outta the box," though a bit bright for me. I padded it down about 5 dB (bottom RTA curve) for a better sounding balance with the LF; in a normal listening environment, it might be fine without that. Mid on "MIN," HF boost on "MED."

Clean and crisp sounding, though not as transparent as the larger 2352/2435HPL combo I compared it to (rear) L vs. R. HF rolls off above 12.5 kHz, then dies above 16 kHz, per spec.

So:

1) Recone 2225's to 2235H,
2) Buy 3110A crossovers,
3) Buy 2380A horns,
4) Consider upgrading 2445J to 2446J (others here can advise), and
5) Retune your cabinets.

Gonna cost about $600 to make this happen, without the 2446J upgrade, and without whatever repackaging you contemplate.

I'd start lookin' for a pair of 4430's nearby, instead....

johnaec
12-15-2005, 06:27 PM
Thanks for running those 2446/2380 curves, Zilch. They really match JBL's published ones closely. 'Should be just fine for my little PA needs, matched with the 2226H.

John

Zilch
12-15-2005, 06:48 PM
Should be just fine for my little PA needs, matched with the 2226H.Yup, I'd say "No problem."

Soon's the forklift charges up, I'll move 'em in for an impedance measurement.... :p

nestawasright
02-04-2006, 09:49 PM
Hello People!
I'm back and ready to complete this project. Well, as far as ready is concerned, we will see if there needs anymore spending as this trip drained me bad. So, we left off knowing that the horns were not the 2380A horns they were suppose to be and also after not having any luck finding the 3115A network.

This weekend I removed the the 2445 drivers from those horns. I will take their measurements and post here. Some have said they would like to know to help me identify what they actually are. I may have to get a pair of the 2380As or based on suggestions, we will see where we could house those 2445s.

I'm proud to say that with some stroke of luck, I have come to own a pair of 2405s and a Behringer DEQ 2496 Ultracurve. We will see how these new acqusitions play out with the project. Especially with deciding on a network that will work best with all the other components. Just to refresh us, those are: the 4647 cabs and 2225 woofers and the rest that have been mentioned.

I have decided not to recone the 2225 after reading and considering the opinions of some friends. I am however very interested in a debate on why it could be considered a wise thing so to do. Who knows, I could be persuaded.

In brief, can we talk on putting the 2445s and 2405 into cabs/horns and decide on a network that will produce optimum output given the components.
Let's talk people. I'm listening.
Micahel



Yup, I'd say "No problem."

Soon's the forklift charges up, I'll move 'em in for an impedance measurement.... :p

Mr. Widget
02-04-2006, 09:57 PM
I have decided not to recone the 2225 after reading and considering the opinions of some friends. I am however very interested in a debate on why it could be considered a wise thing so to do. Who knows, I could be persuaded.It's simple really. If you want deep bass you will recone them with 2235 kits or buy different woofers. If you don't care about deep bass, you'll likely be happy with them as they are.


Widget

nestawasright
02-04-2006, 10:12 PM
The thing is I do want deep bass. In fact I dream of hearing much of it when this is done. I'm not sure who reconing would fit with especially the 4647 cabs. Making another pair of cabs, I must say, is not an option. Zilch has done a good job in letting me know who good these are.
Now you suggested buying different woofers. I would not mind that, but then again we may end up with the same problem of putting woofers in cabs they are not designed for, except of course if they can be found.


It's simple really. If you want deep bass you will recone them with 2235 kits or buy different woofers. If you don't care about deep bass, you'll likely be happy with them as they are.


Widget

Zilch
02-05-2006, 02:38 AM
Welcome back to the fray, Michael! :D

You want deep bass, put 2235H's in those boxes and close two of the four ports. Easily done with Zilch's proprietary port closure devices, available in the plumbing department of your local hardware store, plumbers' test plugs, 3". If you find the bass is TOO deep, you'll just close one of the ports in each cabinet, instead.

As you see, I played Johnaec's 2446J on 2380A with that configuration and it was fine, using 3110A crossover at 800 Hz. It was clear they would need help for VHF, but it seems you have that solved with 2405. So, you need 3110 crossovers (NOT "A" version, which has HF boost, which you don't need, since you're adding the 2405's,) and 3105 (7 kHz) or 3106 (8 kHz) crossovers to drive your tweeters. Your 2445's may play too "hot," and will require a simple L-Pad to balance with 2235H woofers. Your Behringer RTA will help you get everything working together correctly. Did you get the requisite microphone with it? You'll need a stand and mini-boom as well ($25 at Guitar Center) for accurate readings.

Regarding the woofers, several options come to mind: 1) buy a pair of 2235H, 2) recone your 2225H's to 2235H, or, 3) buy a pair of 2225 frames to have reconed and sell your good 2225H's after you're satisfied with the completed system.

Contact this seller, maybe, to find out what he wants for his 2225 frames:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7385229506&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

They come available every 3 months or so on eBay, or maybe a forum member has a pair to sell. Same for the 2380A horns and the crossovers. I may have a pair of NIB 3105 or 3106's here I don't need. I'll check.

It'll cost about $175 apiece to have 2225's reconed, but you'll get half of that back selling your 2225's, maybe more, and you'll have like new 2235H's. That's the best option, I'd say.

Where you gonna put the 2405's? Consider inverting your cabinets and cutting them into the baffle above (then) the woofer. Right size hole saw will do it. I wouldn't until AFTER you get everything working and decide you like the system, tho....

jbl
02-05-2006, 10:09 AM
Hey Zilch,

I have the 4507 cabinet and 2225H (same as the 4647, just that the '47 comes "assembled" with the 2225H installed). Wouldn't a 2235H in that cabinet decrease the "slam" that the 2225 offers? Did you still have the dynamic range with the 2235 as you did with the 2225? I would consider getting 2235Hs and replace my 2225s if I'm not losing that effect.
What were your impressions?

Ron

jbl
02-05-2006, 10:54 AM
Hi Zilch,

Here's my system;
JBL 4507 cabinets
2225H
2370 horns
2425J
3110A

I inverted the cabinets and cut out the necessary space to insert the 2370/2425. The 3110A is located in the rear cut out. The internal volume is appx. 4.5 ft3 with the addition of the 2370/2425J.
Would you be so kind and run some plots with the 2235H in this setup? My main concern is that if I do decide to get the2235H, I may need to pad down the 2425J. Something I'm not wanting to do. Secondly, what would the crossover plot look like? In my present system, the crossover is seamless. Again, something I'm not willing to give up.
As far as a separate subwoofer goes, space is limited at the moment. Others, please feel free to respond.
Thank's for your input.

P.S. Not trying to hijack this thread, just to contribute since the subject is now 2235H related.

Ron

jbl
02-05-2006, 01:24 PM
Some additional information on the 4507. The ports x (4) are;

3" in diameter
6" long

Tuned to 40 Hz

Ron

Zilch
02-05-2006, 03:00 PM
I have the 4507 cabinet and 2225H (same as the 4647, just that the '47 comes "assembled" with the 2225H installed). Wouldn't a 2235H in that cabinet decrease the "slam" that the 2225 offers? Did you still have the dynamic range with the 2235 as you did with the 2225? I would consider getting 2235Hs and replace my 2225s if I'm not losing that effect.
What were your impressions?I understand what you mean about "slam." The 2226H's that came in my 4647's now reside in my 4691B "Party" speakers tuned at 40 Hz. However, they are also supplemented with SUB1500's in retuned 4625B's.

There's a tradeoff, of course. 2235H is an extended bass design using the same motor as 2225. I've always considered 2225/6 more of a high-SPL sound reinforcement woofer, and 2235 as a monitor/hi-fi woofer. There's a substantial difference in the sound. Giskard and others with more knowledge of the actual technical differences may be able to offer more guidance here.

However, a virtue of the 4507 box is that it is easily retuned to use the 2235 in different ways. With two ports closed, it's more like B380 tuning. With just one closed, it approximates 4430 tuning, with "tighter," less extended bass. Giskard has suggested plugging one of the 4430 ports to give them more "Hi-fi" than "monitor" character. 4507 lets you do similar.

My recommendation is the same: Don't recone your good 2225's, rather, buy some thrashed ones to make 2235H's (your reconer may have some, actually,) and try the various options. If you find you've lost the slam you like, and don't like the new sound better (an important qualification, as you may discover it is actually more pleasanty realistic,) you may be able to sell them for more than you have invested in them.

Those boxes and some plumbers' test plugs afford you an excellent opportunity to discover and evaluate a range of bass voicings, and it's not going to cost much in the end to take advantage of that for your own pleasure.... :thmbsup:

Zilch
02-05-2006, 03:31 PM
I inverted the cabinets and cut out the necessary space to insert the 2370/2425. The 3110A is located in the rear cut out. The internal volume is appx. 4.5 ft3 with the addition of the 2370/2425J.

Would you be so kind and run some plots with the 2235H in this setup?Sure. I'll try to get to it this week, and I may have a UHF suggestion for you as well. Let me try it out, first, tho. :thmbsup:

Have you posted a pic of your system in this thread? I'm sure Michael and others would like to see what you have done with your 2507 boxes....

nestawasright
02-05-2006, 03:41 PM
I understand what you mean about "slam." The 2226H's that came in my 4647's now reside in my 4691B "Party" speakers tuned at 40 Hz. However, they are also supplemented with SUB1500's in retuned 4625B's.

There's a tradeoff, of course. 2235H is an extended bass design using the same motor as 2225. I've always considered 2225/6 more of a sound reinforcement woofer, and 2235 as a monitor/hi-fi woofer. Giskard and others with more knowledge of the differences may be able to offer more guidance here.

However, a virtue of the 4507 box is that it is easily retuned to use the 2235 in different ways. With two ports closed, it's more like B380 tuning. With just one closed, it approximates 4430 tuning, with "tighter," less extended bass. Giskard has suggested plugging one of the 4430 ports to give them more "Hi-fi" than "monitor" character. 4507 lets you do similar.

My recommendation is the same: Don't recone your good 2225's, rather, buy some thrashed ones to make 2235H's (your reconer may have some, actually,) and try the various options. If you find you've lost the slam you like, and don't like the new sound (an important qualification, as you may discover it is actually more pleasanty realistic,) you may be able to sell them for more than you have in them. Those boxes and some plumbers' test plugs afford you an excellent opportunity to evaluate a range of bass voicings.
Ron: Don't worry about "hijacking" this thread. You're actually asking some of the questions that came to mind having read Zilch's earlier post in which he suggested networks. Personally for me regarding this, I seem to be going back and forth. Yesterday Mr. Widget made is real simple: if you want extended bass, you'd have to do something about it. The 2225 simply would not do it. So since line Ron, space is a great issue, I'm thinking of getting some 2225 to recone to 2235H. Frankly, I'm scared to recone mine. I can't live without that promising bass, I simply can't. I am however not yet sold on the idea that 2235s will work great in 4647 cabs. I note Zilch did not mention about retuning these. Something seem wrong there. Not quite sure yet.

About those networks; is it not possible that we could find just one network that would do the job of two? For instance, I've been reading up on the 4355 and 4345 to see how well they may work. What are the opinions of others on the matter.

Also, any ideas on whether it's a great idea to build cabs for the 2445 or must I have to buy the horns.

With respect to cabbing the 2405, anyone out there with specs on building cabs for 'em sweet things?

Please find attached the pictures of the horns that some had said they would help to identify. The measurements are as follows:
The driver sits on a 5" wide circular space and has space for four screws used to screw the driver.
It is 2 feet 7" long.
The front end is 2 feet wide and 1 foot 2 inches high.
Sorrry guys, pictures are too big and they won't upload. Until I figure this out, you can look at the ones from earlier and use the measurements. Or send me your E-mail address and I will zip and send. Who knows, I may be sitting on millions :) Your help in locating the cash is immensely appreciated.

Zilch
02-05-2006, 04:08 PM
I am however not yet sold on the idea that 2235s will work great in 4647 cabs. I note Zilch did not mention about retuning these.Yeah, I did, very early on, in post #23:


I DO know the 2225/6H in that box, and you'll likely find you'll want to add a subwoofer to your system for best performance, or replace the woofer and retune the box as I'll be describing in the Q&D thread. 2226H will not provide extended bass, but that which it DOES provide is highly accurate and articulate. Read punchy and dynamic here.

And described it more here:

http://audioheritage.org/vbulletin/showpost.php?p=80359&postcount=71

Showing it done here:

http://audioheritage.org/vbulletin/showpost.php?p=81644&postcount=75

More info about it over in the Q&D 4430 thread with design curves, RTA plots, and all that COOL stuff.... ;)

http://audioheritage.org/vbulletin/showthread.php?p=80162&#post80162

jbl
02-05-2006, 06:44 PM
Thank's for your time, Zilch. I like what you did with those 4507 cabinets! By adding the horn and compression driver into the cabinet, the system is now a 4671 OK.
Mike should listen to his system first then decide what to do. It's interesting that some feel that even the 4430 needs help in the low frequency range. I guess everything is relative. There are major trade offs that need to be considered. The best thing to do is take your time and listen to all opinions from knowlegable members such as Zilch. His experience is top notch.

Ron

Zilch
02-05-2006, 07:12 PM
Anyone near Minnesota want to play along?

http://cgi.ebay.com/Pair-of-JBL-2225H-15-inch-Sub-Woofer-Speakers-8-ohm_W0QQitemZ7388430570QQcategoryZ47095QQrdZ1QQcmd ZViewItem

May hafta win the drivers to get the cabs, tho.... :p

nestawasright
02-06-2006, 02:43 PM
Have you posted a pic of your system in this thread? I'm sure Michael and others would like to see what you have done with your 2507 boxes....[/QUOTE]

Yes, Ron. Would you kindly please post pictures of your system. Zilch is right saying I'd, along with others, be interested in seeing them. Please do. I do listen carefully to what Zilch says act wisely on it aswell. Many thanks for the advice.
Thanks.

jbl
02-08-2006, 08:40 PM
Hey guys,

I don't have a digital camera, but I'll try with my 35 mm. Would that work?

Ron

grumpy
02-08-2006, 09:19 PM
Sure...if you have access to a scanner... even a crappy one.

Zilch
02-08-2006, 10:00 PM
Or get digital copies at the developer....

nestawasright
02-09-2006, 07:54 AM
...And Ron this is me at the moment :bouncy: Thank you so much...it will bring needed inspiration.

Zilch
02-11-2006, 05:03 PM
2425J on 2370A with UHF drivers requires 6 dB attenuation on the midrange driver (white resistors between red and black wires) to balance with 2235H as woofer in 2507 box.

Crossovers are 3110 and 3105, NIB. 3110 MF output set to "Min" to allow 2235H bass to dominate for these plots, but there's plenty of MF output available at "Mid" or "Max." 3105 is set to "about" the middle of the available range.

RTA said both MF and UHF drivers want to be out of phase with the woofer in this setup. Don't generalize from that tho; every physical arrangement is different. The "hole" at 160 Hz is room stuff. Ignore it.

NIB 2402H (top) and 2404H-1 with 2402 diaphragm (bottom). These particular tweeters are documented in the Ring Radiator study elsewhere in these forums.

I'll do the two-way study with 3110A next....

Zilch
02-11-2006, 08:06 PM
Today's testing confirms my dislike for these tweeters in this system: hissy, harsh, whistley.

OTOH, 2407H on OASR or PT-F95 is actually listenable.

AND, it goes well out beyond 20 kHz, for those who can hear anything out there.

See here: http://www.jblpro.com/ae/pdf/spec_shts/AM4200_95.pdf

Zilch
02-11-2006, 09:25 PM
Also wants some attenuation to balance with 2235H. Here, the same 6 dB. MF at "Min," HF boost at "Mid."

I don't see a down side to doing this. Impedance remains the same, and damping's not an issue with M/H compression drivers, I don't believe; there's already other stuff in the path.

Bottom RTA plot is with no attenuation, same crossover settings. Perhaps that's how some might like it. Me, I wanna hear that lovely woofer do its thing.... ;)

jbl
02-12-2006, 11:39 AM
Thank's Zilch. I'm not sure that I want to give up what my neighbor calls, "That exciting sound" my present system offers. Padding down the 2425 may leave me without that factor. It needs more study before proceeding. The 2235H in the 4507 alters the over all sound too much.

Ron

Zilch
02-12-2006, 12:15 PM
Hi, Ron.

Well, at least we know what the options are.

Specs say there's a 4 dB difference.

If you happen across some 2235's, give it a try.

Or build B380 boxes for them and augment your system with them as subs.

Gonna try the 2446/2380A with 2403H and 2407H now....

jbl
02-13-2006, 10:41 AM
Hey Zilch,

Thanks for your time. It's tempting. Perhaps Mike will try it first.

Ron

nestawasright
02-13-2006, 11:22 AM
Hey Zilch,

Thanks for your time. It's tempting. Perhaps Mike will try it first.

Ron

Frankly, I would not mind trying it. My only problem is space and limited funds. The system that Zilch et. all is helping me put together is being tested, the only thing I get to do is physically put the components together. This is the case, at least for now. At some point in time, I hope to explore a whole lot more. But after been in uni for a year, funds are tight at the moment for explorations.

There is no doubt that my present plan cries out for a pair of 2235, be they reconed or original. When I do get them, I'd put them in my 4647 and follow Zilch's porting suggestions. If they don't work out to my ears, and provided I'd kept the 2225s, I'd put them back on and as Zilch suggests to you, use them as sub. Though that may mean getting a different network if and when I do so. I would wish not, especially at this time. I'm, like youself, in the hunt for 2235H. But more for other much need components than them.

Zilch's recent posts are very revealing, in that they show the extent to which we could tweak and rework our systems. For that, I cannot personally thank him enough. The only wish here is that of money, and lots of it. But that's ok, none of us are going anywhere, anytime soon.

...are we getting those pictures Ron? No pressure. Just dying to see 'em.

Michael

nestawasright
02-22-2006, 06:54 PM
Hi there:
I recall a while back that some of you wanted to see pics of the horns I thought were 2380a. So, afer triying for days to get these in the right sizes but could not, I made them into PDF formats to be able to post. They are matter of fact on sale.
Here are some measurements:
The 2445 sat comfortably where you see the holes.
Length: 2ft 7inches
Width (From left to right at the front of the horn) 2ft
Height (on the same position) 1foot 2inches

If anyone can help to identify these, that would be great. As that was the reason suggested of me to gather and post this information.
Thanks all!
Michael

nestawasright
02-22-2006, 07:01 PM
....Ok. I thought I'd post this one. I just tried a tool that works great and very easy. So I'll post this one that I tried it with...

JBL Dog
03-06-2007, 02:09 PM
Hurry Twisted! You might become a Senior Member before the powers that be bust you!

:p