"Best" Woofer 50Hz - 300Hz & Hi eff, maybe 15" ??

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Yes CLS,

Indeed, you are spot on about the beauty of his design.

However, I wonder if a single coaxial playing 2-3 Khz surrounded by other mids is conceptually the same. It looks to me more of a 3 way where the midrange is helped at the bottom by other midrange borrowing the surface area.

What I mean, is that the overall sensitivity of this system won't scale up as nicely as the one proposed by PaulW. The max sensitivity will be the one of the center driver.

@CV,

Believe it or not I was thinking the same a couple of days ago. TD15M looks to be a terrific candidate for a field coil. The massive shorting ring (that's a thing of beauty), the length of the motor capable of accepting lot's of cooper wire, curvilinear cone, all this makes it a great midrange. Potentially the best 15" midrange ever.

Modding it to be a field coil might even add some decibels in sensitivity, maybe up to 102db. But it will still remain a midrange and won't have much output at 50Hz unless the stifness of the spider, surround decreases (or the mass of the cone increases at expense of sensitivity).
 
Changing a driver to a field coil, one that already is at or near the max flux possible with a permanent magnet is not likely to jump it up a very large amount in terms of efficiency or sensitivity since the magnetic circuit is likely already just about saturated anyhow... usually the only way to get more output is to make the gap smaller (tighter) or to put more turns into the gap... all of these things tend to reduce the max output and excursion, and limit the LF extension, as this causes the cone to move too much and can rub... it's a tough world in there!

At least this is what I have been led to believe...

_-_-bear
 
Bear:

You are presenting a tough (impossible?) situation for the people responding: you are asking for suggestions, but then imposing judgements of their sound on the answers. No one can give you an answer you want, because they are not listening with your ears.

I second the suggestions about the JBL 2226, and the TD series, epsecially the TD-X. Contact John @ Audio-Video Logic about a 2226 in a custom built cabinet, flat within 2db of your range, and with felt on the front to tame a reflection. He has a pair for sale.

If you don't like the sound of JBL, go for the TD. Or, try the TAD 1201. 100db @ 1 watt. I ran mine from 100-300, great sound screaming loud. Never tried to go lower, so don't have any idea of what it would do. Mine was in a 1.7cf sealed box, but the driver will work in 1.1 cf. I found a free hunk of 5/8" thick plastic sewer pipe I'm going to stick the TAD in next to see how it sounds. I'd like to try to get the driver down below 60 hz to see if it could work as a nice (not huge) monitor.

Good luck with your project!

yes, it is somewhat impossible, I agree... but not for the reasons you state!

The TAD 1601 works nicely in an isobarik... a bit expensive though... that's to get it to go low in a reasonable size box.

Thanks, but I don't need anyone to build or design me a custom cabinet... :rolleyes:

The idea is to get some feedback regarding folks' experience with a wide range of drivers. Obviously there's no way for me to audition all the possible drivers out there.

But if you read my first and early posts here I think I made it rather clear what sort of thing I am interested in, and the subjective aspect of it as well...

The 1201 (I think discontinued) when I tried them out about 20 years ago I think had the *best* drum impact sound I ever heard from a driver. But I don't know if it was due to cone breakup or not - of course TAD claimed not but I am not so sure... very nice in that regard. I'd advise against a pipe... but you have a go at it if you wish...

Try a TQWT with it? :spin: Of course it won't be compact...

_-_-bear
 
In general, the idea (again) is not a wide range solution - looking for a high output, high sensitivity solution for the ~60 to ~300Hz. "filler" upperbass lower mid range ONLY.

The small driver arrays that go high are another thing entirely.

I did small driver arrays in 1971... with Goodman's Maximus drivers. Look 'em up? Of course newer drivers out perform them in the HF...

I think Bessel Arrays are important for PA/SR and for situations where you just absolutely have to go to some maximum high frequency with an array of rather small drivers... and you can't get the inter driver spacing low enough... tsk, tsk... another design problem! Not so sure they are what you want for a high resolution home system at all. There are better ways to go that have other compromises, but imo represent better total overall results. Or, why that idea isn't commercially popular at any price point?

Anyhow, I think I've restated the aim of this thread... a "to die for" ~60-300Hz. (and I really do drop it out at <300hz. like a cliff) high sensitivity... of course we could discuss the sonic effect on a given driver(s) of a sealed vs. ported enclosure too...

How about a vertical array of 5" TV paper cone speakers, about 24 of them?
(ie. cheap "Fostex" sort of thing?)

_-_-bear
 
How about a vertical array of 5" TV paper cone speakers, about 24 of them?
(ie. cheap "Fostex" sort of thing?)

Well the Alpair 6 I've initially recommended is smaller than Fostex FE126 and have very good comparative reviews. It also has higher excursion.

And in the range you need, 60 to 300, I believe 2x2 or 4x4 arrays won't exhibit the nasty behaviour they're having about say, 800Hz.
 
An array of expensive small drivers is well, expensive... I know that i didn't say that there was a cost limitation, but it would be nice to not have to spend too much on the thing... :D I was talking about a large array of cheap drivers for this narrow range... not a wide range array...

The other thing is not just throwing up drivers, but if you've heard them and they sounded really great! That's the thing.

This range is frequently called the "mud frequencies" - usually avoided, forgotten or not talked about.

_-_-bear
 
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Well one that I own and like a lot is the good old Peerless SLS 830669. Not the fanciest looking driver you'll ever see - but very well engineered and built. Very clean thru, and beyond, the range you want.

It's only a 12", but it's a very good one. It can play darn loud, too. Nice clean driver.
 
AE TD15M/TD18H+/JBL 2268H

It only gets better with a pair of whichever one you pick. Preferably wired out of phase and mounted in-line for reaction force cancellation, 2nd harmonic reduction, lower overall distortion and higher SPL capability.

EDIT: If price is a concern, how about an array of Dayton RSS390HF-4 15"? Great bang for the buck.

EDIT2: Didn't see your sensitivity requirement. The Daytons won't work unless you get lots of them. You'll definitely want to go with pro woofers.

Honestly, I think you might be overkilling things here. This is a very easy range to reproduce as directivity is easily set, distortion can be taken care of simply by adding drivers (and there is no shortage of good ones) or working with the enclosure size, and frequency response can easily be modeled to suit your application.
 
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