Trying to build dipole sub - a la Celestion 6000

Should add that Madisound offers a service to precision cut the wood.

For this purpose, there are some pro amps that offer gain control, delay, crossovers and DSP along with gobs of advertised power for between $500 and $1000. Crown XTi series, Peavey, Powersoft, etc... Even saw that one had RCA's.

Wow,

Thanks a bunch for all the tips.

I was looking into direct drive woofers to deal with potential ringing problem of the drivers.

I have the behringer dcx2496 serving as the active cross over in my setup. So it can do some degree of DSP and filtering if need be.

I currently have more great amps than I should. I'm using my mccormack DNA 500 for bi-amp for my bass currently. I also have another pair of VTL 450MB and nuforce amp on standby as well. My primary amp is a pair of Ampzilla 2000 MKII driving my electrostats right now.

I probably will go with with a crown or peavey in the long run and sell the other amps if this sub arrangement works out.

I don't know if any of you has seen/heard the Celestion 6000 bass system. It is configure with the woofers firing directly into each other with only about 6 inch gap. Haven't figure out how all that works, but what comes out is clean tight bass that can really rock a room. My friend drives his system with just a old Krell 100 watt KSA amp; and that 100 W was more than enough totally roch his music room. Although the 100w krell can be deceiving as it can pump linear amount of juice as impedance goes down; all the way down to 1 ohm.

Does anyone know of a design for dipole sub where the woofers fire into each other like the celestion?

The reason you don't see much of this is because there's not many crazy enough to try. "Dipole subwoofer" is about as close to an audio oxymoron as an unbiased opinion.

NgJockey,

Interesting point you raise there...

I am amazed at the results the Celstion 6000 subs have been able to produce.

I'll have to look into the links provided above to research this better.

I built Siegfried Linkwitz's Orion design, have run them in three different rooms so far, and have heard a handful of other Orion setups and other dipole bass/sub-bass setups in different places. They work great.

I've also heard Martin Logan's attempts to integrate monopole woofers with dipole main panels and that doesn't work well.

Ngjockey writes
>The reason you don't see much of this is because there's not many crazy enough to try. "Dipole subwoofer" is about as close to an audio oxymoron as an unbiased opinion.

As long as we're being relaxed about defining "sub woofer" like the original poster that's extending the headroom and extension of his electrostatic main panels or the consumer market definition which extends to 80Hz or beyond:

Compared to monopoles there are significant perceptual and measurable differences in how dipole bass couples to room modes (with adjustments possible through source rotation), has no gain below the space's fundamental resonance (why you can't put "big" conventional speakers in small rooms), has a different energy time curve, and has a more accurate modulation transfer function resulting from the speaker/room interface.

People don't do it because it's expensive. In a domestically friendly 14" deep enclosure you need four times the displacement of monopoles for the same SPL at 40Hz and 8X at 20Hz. For music the 40+ Hz output is the issue since even "bass heavy" music has last octave peaks 10-20dB down from the rest of the spectrum with the IEC musical power spectrum approximation specifying a second order high-pass at 40Hz. For mixed home theater use you also need a separate monopole sub-bass system for the lowest frequencies and probably LFE unless you take the Monte Kay approach using 24 15" drivers split into two 9' tall W-frame stacks with a total 1400 pound weight (That does yield 103dB @ 2.83V / 1 meter sensitivity at 18Hz with a 1% second harmonic and 1.5% third harmonic).

That's not very viable commercially in a world where designers lament that $8000 per pair MSRPs only allow for $80 midrange drivers and consumers would need to buy both dipole woofers and monopole sub-woofers for home theater.