Search for the Best Driver (1 Viewer)

[Brian Bunge]

Allen,

Non-parallel walls is a waste of time for a subwoofer as standing waves will not be an issue. The wavelengths being reproduced are significantly longer than any of the enclosure's internal dimensions.

And yes, what Jack is asking is what are the specifics about the enclosure you plan to build. What internal volume, tuning frequency, port size, etc.

Brian

 

[Allen Ross]

well from what I have heard a nice things from a 13ft^3 with dual 4" ports, or should I opt for a 6", I don't know much about tuning, other then it is adjusting the lenght.

so if i went with the tempest with a rectangle base, to include the dual ports, of 20"X24" and a hight of 50" would this be too big

Can I reduce the box foot print if I make it front Fireing, and just making it taller

 

[Tom Brennan]

Allen---High efficiency 15" drivers with light paper cones and large edgewound voicecoils working in overhung gaps, Altec 515s and 416s say, do make the best woofers, alas they're not good at all for subwoofing. Even in huge vented boxes one is hard pressed to get such drivers to respond below 40hz. That's the nature of things, the very attributes that give them their high efficiency, hair-trigger dynamics and excellent midband response keep them from plumbing the very low bass. Tradeoffs.
One can get good low bass and high efficiency by ganging-up an array of medium efficiency drivers and using a little EQ, my 4 JBL 2226 15" woofers respond flat to 25hz with about 100db 1w1m efficiency (106db before subtracting for the EQ used); the downside is 16 cubic feet of enclosure, $1400 worth of drivers and the inelegant practice of 6db of boost below the driver-enclosure tuning frequency. With lesser drivers than the stout 2226s I doubt this approach would work.
Had I not scored the JBLs dirt-cheap from JBL Pro's online tent-sale I would have gone with Bruce Edgar's Seismic horn subwoofer which is only $1000 as a knock-down kit but is the size, literally, of a Frigidaire.
Nope, high efficiency AND deep bass don't come easy.
www.chicagohornspeakerclub.org

 

[Greg Monfort]

>Nope, high efficiency AND deep bass don't come easy.
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Sure it does, it just don't come small/cheap. IIRC, TW's Twelve Dancing Shivas IB is around 100dB/2.83V/m/20Hz.
Interesting that you use EQ below Fb, down where the cab has no control over the drivers and are out of phase. I tune low (16Hz), then let the room help, along with a bit of EQ above Fb to blend the driver to the boundary gain. I hear you WRT the size issue though, two 20ft^3 cabs to hold two 515Bs each really fill in the room corners. I recently bought a large RPTV and didn't have to pull the speakers forward at all to line them up with the screen.
GM

 

[Allen Ross]

thank Tom great information, I am still going to have to think about it.

But are there any other drivers that compare to the Tempest, Shiva, Dayton DVC, Stryke, or are these my only option

 

[Dustin B]

There is BluePrint. The rest are no or little gain over these for a lot more money.

 

[Anthony_Gomez]

But you WILL have to actively EQ with the BluePrint 03 series.

 

[Bill Fagal]

Don't overlook the Aura or its Leviathan derivative, as Anthony mentioned. If you can afford them, they really push the limits, efficiency and performance-wise.
Bill

 

[Anthony_Gomez]

I think one of my ultimate single drivers would be the leviathan (or the likes), or perhaps one of the cost no object. SuperHE drivers that John J has in the works (won't be released for some time).

 

[Tom Brennan]

Greg---Well I kinda arrived at things by accident. I use Altec 515Bs in 825 cabinets, A-5s. As you may know these cabinets have a stepped response with the reflex loaded area below 100hz several db down in level from the horn-loaded area above 100hz. I bought a couple of the JBL 4648 theater bassbins with the idea of fleshing out the bass below 100hz. The 4648s have an F3 of 40-45 hz in half-space and I figured with room gain they'd go a little deeper but response down in the 25-30hz area was not on my mind at all.
So I bought a PE plate-amp to power the 4648s, an amp that has 6db of boost at 30hz. Knowing that boosting a vented box below resonance is a no-no I'd planned on removing the boost circuit as is outlined in the tech sheet that comes with the amp. But on listening there were no ill effects and on measuring with my RTA, lo and behold, 3db down at 25hz. This was a happy surprise and not my intent. But it's working. I'd be loathe to try a single driver like this but with the load spread out among four 15" drivers (and the 515s are still helping, the A-5s are not high-passed) and with the incredible stoutness of the 2226s all is well, indeed I see very little cone movement even at very high levels. A happy accident I suppose.
www.chicagohornspeakerclub.org

 

[Greg Monfort]

>I use Altec 515Bs in 825 cabinets, A-5s. As you may know these cabinets have a stepped response with the reflex loaded area below 100hz several db down in level from the horn-loaded area above 100hz.
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Yeah, I had A7s back in the '60s and just looking at an old plot I did, they dropped ~10dB from 250Hz to 60Hz, rolling off at 24dB/octave below this. And to think these used to be considered as having kick-ass bass. Technology can be a Beautiful Thing.
====
>But it's working. I'd be loathe to try a single driver like this but with the load spread out among four 15" drivers (and the 515s are still helping, the A-5s are not high-passed) and with the incredible stoutness of the 2226s all is well, indeed I see very little cone movement even at very high levels. A happy accident I suppose.
====
Indeed. For sure, having six 15" to share the load helps a bunch, even with just four I only get obvious cone movement when playing movies with LF snyth tones or organ music. It's the organ music that made me initally tune lower (32Hz) to get all of a record's response, and finally down to 16Hz to get all but only a few CD's currently have.
GM

 

[Allen Ross]

Bill thoses are the nicest drivers I have seen, but too big for my tastes, 15 is the max. do you know of any smaller subs from Aura?

Well as I have scoured the internet it seems that I am looking at either the Tempest, or the Dayton DVC 15" I am leaning twords the Dayton because of the higher SPL but I am still not sure I will try and plug the T/S into my freinds program and see how they perform.