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Posted by homebuilder on
01-02-2008
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I am new to this interesting site, and am hopeful of getting some assistance with a project. I have purchased a set of TAD 1201 mid-bass drivers to begin a 4-way active system for critical home listening. (in a dedicated room, 21' x 25' with peaked seilings at 11.5') I already have the balanced x-over, and tube and solid state amps.
I plan on either the JBL 2226H or 2241H for the bass, and the 2404H for the treble. My problem lies in the midrange. I'd like to use the 2344a horns with 2426 drivers, but cannot locate any of the horns. Any help there? Or, I have considered using either one, or a pair of large cone midranges, such as the JBL 2012H. Is it practical to use large drivers such as the 2012 in an MTM arrangement?
The cabinet will be built of HDF, and will be multiple layers laminated on top of each other. It will be nearly round. Very heavy, massively braced. I have friends with a CNC router, so that is a huge help.
Does anyone have any suggestions for the midrange? Other horn combinations?
Thanks!
Greg
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Posted by Romy the Cat on
01-02-2008
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 homebuilder wrote: | | I am new to this interesting site, and am hopeful of getting some assistance with a project. I have purchased a set of TAD 1201 mid-bass drivers to begin a 4-way active system for critical home listening. (in a dedicated room, 21' x 25' with peaked seilings at 11.5') I already have the balanced x-over, and tube and solid state amps.
I plan on either the JBL 2226H or 2241H for the bass, and the 2404H for the treble. My problem lies in the midrange. I'd like to use the 2344a horns with 2426 drivers, but cannot locate any of the horns. Any help there? Or, I have considered using either one, or a pair of large cone midranges, such as the JBL 2012H. Is it practical to use large drivers such as the 2012 in an MTM arrangement?
The cabinet will be built of HDF, and will be multiple layers laminated on top of each other. It will be nearly round. Very heavy, massively braced. I have friends with a CNC router, so that is a huge help.
Does anyone have any suggestions for the midrange? Other horn combinations? |
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Greg,
So, it will be:
2241H for the LF
2404H for HF
TAD 1201 for mid-bass
MF channel
….the 4-way system. What kind enclosures are you intend to use? The 2241H is a ported-type driver, with somehow pro-like bass. Thos pro drivers are better in midbass then in lower bass. The 2404H is high-power SS-require tweeter, something suggests me that it might not be your finals chose if you consider “critical home listening”. TAD 1201 is a “terra incognito” for me but it looks like a very interesting driver. Still it is unknown how you will be using then: horn of boxed. If your go for no-horn-loaded MF and they all will be boxed then you might consider symmetrical double driver configuration with a tweeter in a middle and then two MF driver, two midbass drivers and two woofers. As MF might be anything you like, but I would start with JBL L8. I hope your rest of the driver will be able to keep up with L8’s tone (and you should not wary about the sensitivity as it will be active anyhow). You might consider even to put MF in open baffle in that case… If you go for TAD 1201 in horn then it would be a different game and you might look for a compression driver for MF.
I generally am very uncomfortable with recommendations unless a lot of specifics in play. At this point I do not feel that you have a clear and defined vision what you are trying to build. I might advise you to do what I always do - starting to talk with your driver that you already have. Connect your TAD 1201 to the amp that you know and play it full-range for a while. Use different music, learn how the driver reacts to damping, reacts to volume, reacts to crossover and etc, etc, etc… You need to get a feeling where are the strong and week moment in a given driver and then come up with an enclosure that will accent the driver best qualities and shadow out the driver weak qualities. Pay particular attention to the diver upper range as wherever you feel it will “slip” you would need to introduce a MF driver. Then, when you will try the MF driver you would need to look for the midbass and midrange driver TTH compatibility…
I call this approach a “Derivative Design” and it is the only approach in my view how an acoustic system might be planed. I have writhe about is many times. This method organically includes the person understanding of sound and the ability of acoustic system to present sound… The problem with this apprise that it takes time…
Rgs, the Cat
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Posted by el`Ol on
01-03-2008
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JBL developed the PT-Waveguides not only because they are easier to produce. They also have less harmonic distortion than biradial horns. Disadvantage: They look far less funky.
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Posted by Romy the Cat on
01-03-2008
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| el`Ol wrote: | | JBL developed the PT-Waveguides not only because they are easier to produce. They also have less harmonic distortion than biradial horns. Disadvantage: They look far less funky. |
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Why JBL developed their PT-Waveguides and how “better” it might be is very easy question if to look at the JBL objectives. The JBL-like companies, particularly in their horns development, do practically nothing that might be applicable for home listening. The PT profile with its stressed off-axis advantages is not really innovative or “developed”. More shallow horns act more and more as a direct radiator and has wider radiation pattern, it also provides less LF EQ. JBL make a family of compression drivers that meant to work in those low EQ environments and then they “invented” a bogus term Progressive Transition. Sure for PA allocations where DJ need with two speakers to cover wider area of a dancing floor the PT horns are better but who care about sound quality for DJ applications? Interesting that those contemporary “PT-compatible” JBL drivers when they loaded into the “full-EQ horns” do not do very well. Do those drivers do well in PT setting? It is hard to say. Certainly the top of the line JBL PA system do very well, much more interesting than many of their competitors. Still, how serious should we accept those results for home use? I do not think that they are usable at all.
The Cat
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Posted by homebuilder on
01-03-2008
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Romy:
Thank you for your response. You are correct that the vision is not completely developed for this 4 way. A bit more info is needed. I've had some experience with JBL woofers, but am relying heavily on the results achieved by a good friend who has a 2226 ported, 2344a-2426, and 2404H sitting on top in a heavy steel framework. 3 way active. He purchased the TAD 1201s from Nelson Pass to augment this system, but never built the new cabinets. I bought the TADs from him.
You are right on the money about the TAD...I plan to build the midbass cabinet first, and listen to it, probably with my ARC VT-130 tube amp. That driver is amazing, but I plan to restrict it to 200/300-800/1000 range eventually. For this, I will build a laminated constrained layer cabinet of 1-2cf sealed. We will use threaded rod and angle iron to bolt the sections together, so we can vary the internal volume by adding or subtracting 3/4" layers; as we listen. After the volume is finalized, it will all be glued up properly. My plan was to hold off on the 15" vs 18" JBL until the verdict is in on the TAD bottom end. The 18" has more severe breakup than the 15" past 200hz, but goes a bit lower. I'm also worried about midrange/tweeter height, and the 18" makes it just that much taller.
I plan to get the 2404H soon, and will start using them with the TAD 1201 as a 2 way, for awhile. All drivers will be in independent cabinets. The bass cabinet will be 4.5-8 cf range, by the way.
An important part of this project is the woodworking aspect...I'm not in a hurry. I have waited 25 years to get my dedicated audio room, I can take time to develop the right combo. Some of the JBl drivers such as the 2118, 2123, etc look very interesting for this aspect of the project. I am particularly interested in ideas along those lines. I've listened to several open baffle designs, and in general find them very appealing. I wanted to try an infinite baffle sub, but the rooms adjacent to my audio room just won't allow that.
Finally, my room has angled corners at the front, where the side walls slope down. They could house a massively braced cabinet, if that made any sense. The internal volumn is pretty large, could be as much as 45cf, even if sand filled
construction was utilized to brace it all. I have read a lot about various horn combos, but have no experience or idea of what would happen if something were built into the corners of my room. I suspect a subwoofer would be just fine. I am worried about the effect of the sloped ceiling. The ridge runs front to rear along the center of the room, tapering down to sidewalls.
Thanks for your help!
Greg
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Posted by Romy the Cat on
01-03-2008
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Greg, I see a regions of concerns that you might contemplate.
TAD 1201 might be good driver but how useable would be the 200/300-800/1000 range? Let pretend that you end up with 250Hz, then what next? You will introduce a bottom octave section but to cover a range from the very begging to 250Hz is practically impossible with one driver. To reproduce 30Hz and 250Hz is require VERY different type of drivers otherwise it will be a compromise in one of other extremes. In your room of 21’ by 25’ I would like to see driver with Fs of 20Hz in 25-30 enclosure – those types of the drivers will never go up to 250Hz. In a contrary if you go for 35Hz bass drivers (typical JBL) in 45Hz enclosure then in your room you will not get the lowest octave. BTW, did you consider to EQ down the TAD 1201 with a horn? It is 52 Hz driver and in a horn you might easily to push the driver to down to 100Hz or even lower. Do not forget that horn wills EQ the driver + it will have add a few dB at LF that will minimize the excursion…. They are 12-inchers so, 7-8” throe would do most likely… Though I have to warn you that I am generally horns-biased… What I mean was that if you already have 4 of those 1201 drivers (you intended to use then in MTM configuration) and if you found them “amazing” then it might be a plausible direction:
I would encourage you to think about the “MF Island” separately and then just add a complimentary LF sections - it might help you to deal with the issues of your room.
The caT
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Posted by homebuilder on
01-03-2008
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Romy:
Thank you for the reply. First, a correction: I have a pair of TAD 1201. The MTM idea would utilize other drivers, such as the LE-8, 2118, etc. I'm certainly not against buying another pair of TAD, however.
The 1201 will definetely go lower, such as you suggest. And, active EQ will be a part of this project, along with in room measurement. My friend will do the honors on that. I have not purchased an EQ yet. On your idea of horn loading the TAD: how critical is the shape of the horn? I've seen billions of ideas, but don't know where to start. If we horn loaded the 1201, would we not also need to do the same with the bass driver? Or would your 25-30 (cf?) do the trick? I assume that is ported? Everything considered, if necessary, I would first sacrifice the lowest octave, since I have little music that contains much in that region. However, building a pair of subs in the corners of my room would be very simple, and can easily accomodate even multiple drivers. The mains need to get to 35/40 hz, and do it well.
Do you have any experience with drivers of this type in OB configuration? What is to be expected?
Greg
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Posted by Romy the Cat on
01-03-2008
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| homebuilder wrote: | | ...active EQ will be a part of this project, along with in room measurement. My friend will do the honors on that. I have not purchased an EQ yet. |
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You might eventually revise your view about the active EQ and presumably crossovering. If you go for an active system (will have) then you do have 4 amps and therefore I see no needs for active EQ. The necessary for you EQ and crossovering might be done passively at line level. You might buy or borrow an active unit, perhaps digital unit to plat with it but after you defend the necessary slopes and cut offs than you can replace the active unit with fixe line-level filter for each power amplifier. With EQ is the same but it all depending: for what you will be using your EQ. I hope you will not correct with it your room problems… If you need EQ to push a little the edge of one of other channel then it is fine (as lond as the filter was not closed in this channel) and you might do it very easily at line level.
| homebuilder wrote: | | .… On your idea of horn loading the TAD: how critical is the shape of the horn? I've seen billions of ideas, but don't know where to start. If we horn loaded the 1201, would we not also need to do the same with the bass driver? Or would your 25-30 (cf?) do the trick? I assume that is ported? |
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Well, I personally do not accept any ported enclosures, but it is me. The horn for 1201? I really do not know. I never saw or heard this driver. It would be too brutal to advise you to experiment with it yourself. Try to found some your local guys where you would be able to listen some upperbass horns and to try your drivers in some kind of horns. In your part of the country you might have difficulties to find anyone horns-civilized. You are from Iowa if I am not mistaken. Indians should be somewhere near you, one state over. Try getting in touch with John Hasquin, he was semi-retired few years back unit his wife finish her school be you might wake him up. Right across Missouri will be Tennessee. In there, in Memphis there is Jeffrey Jackson. I did not see or hear his speakers but he had popped up a few time at this forum and in conversation about horns he sounded surprisingly inelegant. I said surprisingly because you might discover that many people who talk about horns should not be doing it. So, perhaps Jeffrey or John deal with those drivers and they might inspire your to look into a horn direction or might introduce you with their local customers where you might get familiar with upperbass horn opportunities. To design the final horn for that driver is very-very simple task but you would need some kind of prototype horn to learn about the Sound of this diver horn-loaded.
| homebuilder wrote: | | Do you have any experience with drivers of this type in OB configuration? What is to be expected? |
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Nope, I have very limited building experience with non-horn speakers. I comment only upon the things that I personally did and was able to obverse the success/failure patterns. Although many drivers that I have used sounded fine in OB configuration but I never use OB in context of complete system. So, I truly have no experience with it. There is a guy out there: Duke LeJeune. He runs a sweetshop somewhere between you and the west coast; I think it call Audio Kinesis. He being a dealer compromises himself by socializing with many audio idiots but all together I found him being a positive character. He knows what he needs to know in his business and he is TAD dealer or respective - I do not remember already. Anyhow, he does know TAD line very well, including some uncommon drivers and he might used or know somebody who use your drivers. The caT
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Posted by Wojtek on
01-04-2008
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of MTM arrangement of two TAD 1201 in <100 Hz Horn ? I assume they would both work in the same frequency range . Also JBL LE8 is only 89 db driver and it doesn't look like it can take any power . Difference in efficiency within the channels would be huge.
Did any of you guys tried altec 15" biflex driver (420A-Y )? It is alnico 97 dB with o.4 QTS and ~20 Hz fs . I read that in 10Cu.ft sealed enclosure it reaches comfortably 25 Hz and because of kinky fulrange construction should not have problem with 350 Hz.Many people disregard this driver but I gues most of them used it full range with tweeter helper. I wonder how it would fare in bass low-mid bass range. (I'm not very anxiuos at the moment to build 10cu Ft boxes just to check it out .
Roman ,
could you (or enybody ) elaborate a little bit on JBL L8 and its application ? Not so much sensible info on the net besides that its a fullrange usefull in 40Hz-8kHz . I have a pair of JBL Lancer 33 speakers -~1.5 ported with single LE8
with recently changed surrounds which have not been played for a long , long time . I remember some remark on this site on the question " what if not Mid-bass horn ?"and the answer was ported enclosure with low tunning -anybody tried this with LE8?? So far my drivers are sounding a little "hollow and dark" in midrage but the low midrange -midbass have strange -not sure how to describe it "ambiance " .Regards, Wo
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Posted by Romy the Cat on
01-04-2008
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| Wojtek wrote: | | Roman, could you (or enybody ) elaborate a little bit on JBL L8 and its application ? Not so much sensible info on the net besides that its a fullrange usefull in 40Hz-8kHz. |
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I do not know, how can I elaborate if I never tried to build any seriously sounding direct radiator speaker? Back in 200-2001 when I was experimenting with a driver for Avantgarde’s Trios upper bass horn I played a lot with all imaginable 8” drivers. Sine I had no knowledge and generally do not believe to what other people say I went for empirical evidences, buying all interesting 5-8-inchers and experimenting with them. The JBL L8 impressed me as a driver with surprisingly-serious tone, though it was not horn-type of driver of course. It has a ringy dust cap but it is possible to deal with it damping it with Aquaplus or with table tennis glue.
| Wojtek wrote: | | I have a pair of JBL Lancer 33 speakers -~1.5 ported with single LE8 with recently changed surrounds which have not been played for a long, long time. |
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Well, those old cheap JBL speakers with LE8, with all their problems and with very moderate volume were very nice. Borrow somewhere Lamm ML2.0 to drive them (very critical) and you with those old and crappy JBLs will get a quality of Sound that will be more superior than anything else about which “The Absolute Sound” has wrote for the last 10 years, particularly in midrange
The Cat
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Posted by Wojtek on
01-04-2008
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"Borrow somewhere Lamm ML2.0 to drive them (very critical)
and you with those old and crappy JBLs will get a quality of Sound
that will be more superior than anything else about which “The Absolute
Sound” has wrote for the last 10 years, particularly in midrange"
..to breadboard your Melequiades full range amp with Czech 300BXL for me than try to find Lamm ML2.0 within 500 miles radius in Midwest . The only concern being that ML2 is a feedback amp and Mel not.
Thanks!
Greg
Small Lowthers (DX5 or its alnico version ) may be an interesting option for midrange driver in you project .
Regards, L
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Posted by Romy the Cat on
01-04-2008
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| Wojtek wrote: | | " The only concern being that ML2 is a feedback amp and Mel not. |
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And it is exactly why Lamm is able to drive more or less successfully those sub 90dB loads but Melquiades is not. The SETs with no-feedback are VERY sensitive to loading and to many other sings. Also do not forget that ML2, due to the output stage regulation and the dual triodes in second stage should be able to drive 6C33C closer to A2 – the mode where the amps will be operating when it drives those sub 88dB loads. I still would not use ML2 for sub 90dB speakers and would advocate it use with them ONLY for the sake of illustration. The 6C33C is 5W-6W of “good watts” tube, but it is a whole other subject…
The Cat
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Posted by Romy the Cat on
01-11-2008
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Greg,
BTW, if you go for direct radiation and would like to go for Dunlavy-like symmetric configuration (perfect for along wall) then here is for you an idea that I do like very much. I took that idea from old version Kharma Audiocritique and made it more swallowable-visually. This year the Evolution Acoustics MMthree did (shape-wise) almost exactly what I envisioned: water-dropped Dunlavy. I LOVE this design and if I live in a world of direct radiators then I would do something like that. Add to the speaker one more layer of upper bass drivers - making it MMfour and use the real MF drivers (not the ceramic crap as the Evolution Audio uses) and it would be it.
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Posted by Paul S on
01-11-2008
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That sure looks like an interesting configuration for a change , all right, but are those "ceramic" drivers, or what? Does anyone know?
What's with all the "space age" materials these days? I mean, are people actually listening or do they just "specify" and then build and then use the stuff based on "computer modeling" and "engineering briefs"?
After those unholy (and now ubiquitous!) Be tweeters you'd think they'd learn a lesson and give it a rest.
I heard some big Dunlavys years back that were actually promising, among the few comercial speakers of interest, IMO, at least at the time (along with the big Avalons, and maybe a couple more). Not cheap, but some shoppers have more money than time but nothing worthy to buy.
It almost seems like real sonic acceptability on the commercial front is pretty much accidental, and then "designers" tend to drift away from their sonically interesting "products" and move on to bad-sounding "improved" stuff.
Tip to Shoppers: When you run across something good that is offered comercially, don't wait for the next "upgrade", and don't wait to chisel the price if you don't have to; just jump on it because it might not come up again for a long time.
Otherwise, your fate is DIY...
Best regards,
Paul S
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Posted by malinowski on
01-12-2008
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Hi Greg,
link
Search the site and you'll find that Ulf has created a upper bass horn using the aforementioned TAD 1201's.
I also own a pair still in boxes waiting for the weather to warm up enough for me to start some enclosures and horns for.
My original intent was to build a direct radiator setup as follows:
ScanSpeak 25W/8565 - lower bass - sealed enclosure.
TAD TL-1102 bass.. sealed enclosure
TAD TM-1201 upper bass- mid sealed
supravox 165 2000 upper mid
raal 70-10 highs
i'd active crossover with 2 behringer ultradrives and a handful of cheap t-amps until i could build something more akin to the super-malq
however that started to seem like a lot of money and work for a "temporary" rig.
Now leaning towards following Ulf's example.
Horn load the TM-1201 and put a pair of JBL 2441's or something like that over them for a start.. wouldn't be too expensive..
listen until these are integrated properly and then add the lower and upper drivers.. an array of 25W/8565 below, a 1" cD and horn and Raal tweeter above... something like that.
Anyhow those are some ideas.
Also I would second Romy's suggestion to contact Duke LeJeune I have purchased from him in the past and he is one of the few persons I find interesting and trust.
He was able to send me some of his own measurements for some drivers which was helpful.. he's also not a fan of compressed sound so...
Good luck.
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Posted by Romy the Cat on
01-12-2008
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I do not have lot of experience with TAD cone drivers but there is a thing bout then that always afraid.
A few years ago I was at demonstration of Model-1, the TAD’s $50,000 flagman model and it had very strange feeling – the speakers sounded surprisingly pleasant but at a certain dynamic level everything stopped. It was some kind of threshold compression and further then that abstract “dead point” nothing was able to move: dynamic, tone … everything was literally stopped there.
I still have no ides what it was – perhaps it was not the TAD drivers, but I never seen this effect so strong in any other speaker. I spoke with the designer and learned that the Model-1 did not use standard drivers but custom made by TAD drivers. When I sled him about the “threshold compression” he began to express doubts that I am in a sane mind as he thought that that sound he was presented is flawless. I left him alone as I generally avoid people who have no capacity of critical thinking about sound or can not effort the critical thinking.
The negatives outflow was that I still do not know what it was in case of the TAD’s demonstration. Was it the crossover, the divers or the electronics that introduced the “threshold” – it is unknown to me. Still, if I touch the TAD cone drivers I would test them for the presence of the “brickwall effect” The Cat Romy
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Posted by Romy the Cat on
01-29-2008
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Thanks, El, an interesting driver indeed. It would be interesting to listen the thing though I have personally no use from that type of driver. Purely on the specs there are some moments that I would like to see different. The 250Hz resonance frequency with 300 power handling and excursion of 9mm? Take a look where I see it doing: how about the 100Hz resonance frequency with 20 power handling and 9mm excursion? Also the size. It looks like 7-8 driver to me it is too big to load into a MF horn. It might be good direct radiator however. Sure it should be heard to make any accurate comments… BTW, the company has a lot of compression drivers, did you have a chance to use them? Are they interesting?
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Posted by el`Ol on
01-29-2008
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I didn´t have a chance to listen, but I am very interested in the lower cost polyethylene drivers. When I first read this I thought it is a joke. I wonder how that sounds.
Seems that in home audio the horns are currently more popular than the drivers. I am currently thinking about a fun project with them: Take some pairs of NOS B.I.C Venturi drivers from the seventies, combine them with the smallest Eighteensound horns, take these seventies style orange cubes as enclosures that are currently modern again (two way speakers) and sell them off at Ebay (in the furniture section). Not for earning money, I am just interested whether there is a demand for something like that.
For normal (even pro) use I find the 6.5"er more interesting than the 8"er:
http://www.eighteensound.it/index.aspx?mainMenu=view_product&pid=244
I just thought 31Tm for a midranger, that´s sick.
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Posted by Romy the Cat on
01-29-2008
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I never seen the polyethylene drivers but I would not say that it would be a joke, I would rather say that I have no idea what to expect. The SL600 MF driver is a polyethylene-like driver and it does have some interesting qualities, Sure it you drive it under 120Hz then the SL600 MF driver begin to sound like shopping back trembling from wind gust but above it does very nice. There is another consideration why I would not consider a polyethylene driver as a joke. With my horno-snobbery I hardly see a driver as a potential direct radiator but I see them only a candidate to be horn-loaded. There are absolutely no rules of prediction what will happen with sound when a driver is horn-loaded. You can put a farting porcupine in the throat of a horn and it is suddenly might throw a good tome out of horn, I have seen it, so go figure…
Regarding the Eighteensound 6.5"driver – it looks good, however I have some concerns. You see, the Eighteensound driver is a pro driver that made for higher power handling – it is never good and there are a lot of reasons why. There is another aspect. Those drivers have the cone treatment that makes the cone suitable to work outdoor in moisture weather conditions. Usually it is done with different propriety treatments; all of them impregnated rubber-like minerals into the body of the cones. Those rubber-like deposits are not good for sound as they overly dump the cones… There is a catch however. If you buy 30-40 years old Altec, JBL, Vitavox and so on cone drivers, that mostly had the similar impregnation then the rubber-like mineral are faded away and become less contributive. Those “dried out” drivers as VERY sensitive to moisture outside but they do have way better tone then the “new” cones. I made some experiments in past, comparing the 30 years in air good cone driver and reckoning then with identical original come that was sitting for 30 year in a sealed plastic back – the difference was VERY notable. You do not need to listen the driver and can juts scratch them with you nail – you will immediately feel the “dryness” of the cone… The caT
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