Do audiophiles hate large subwoofers?

@bdp24 

Yes, thank you, I must confess I did think long and hard about Danny's servo subs. They were quite attractive to me.

I wound up going with going with Crown XTi 2 amps and a pair of Acoustic Elegance 18" Dipole woofers (on order) for the mains and a single 18" Infinite Baffle woofer to be mounted in the front wall behind the main speakers. The Crowns for their unlimited crossover, delay, EQ options (which buys me future integration with any conceivable change I might ever come up with in the future in the way of woofers, subs or placement), and the Acoustic Elegance woofers for their efficiency at lower frequencies and their unique "lambda motors"...very low impedance for an easy load for the amps.

But when I looked at Danny's Rythmik plate amp, according to its specs, while the upper crossover control went fairly high, the response of the amp itself was terminated in such a way that if I ever needed a relatively high crossover point like the one I was already contemplating, then the upper roll off in the response of the plate amp itself would leave me a slight "hole" in the crossover zone up toward the hand off point to the midrange...the very kind of response error in my setup (with smallish midrange drivers [MMTMM]) that I could ill afford to have. (I find myself currently and happily wedded to a version of Danny's superb "Wedgies" main speakers that are Well worth all this fussing over them!).

BTW, for my money, Erik nailed it when it comes to subs: integration is king!...and yes, it can be a tough thing to find.

Speed doesn’t matter. Integration is a misleading misnomer. There’s more out of date thinking on low bass than anything in audio. And that’s saying something!

Speed doesn’t matter. If speed mattered then my Talon Roc would be the King of subs. Why? Its isobaric design guarantees the driver moving the air sees no pressure variance behind it. It is indeed a very fast sub. Which does not matter. Why? Because with low bass unlike higher frequencies we don’t hear the sound coming off the driver. We hear only the waves that have been bouncing around the room many times already. Low bass waves are so long they create many modes and cancellation areas. In the modal areas the bass is so strong it takes a long time for this energy to dissipate. We hear this long slow dissipation as slow bass. So the answer to fast bass is smaller modes. The way to get smaller modes? More subs! So its not the speed or power of the subs that makes for fast bass. Its the number. The more subs the better.

The whole concept of integration is misleading. Integration creates a false impression. Integration makes people think the subs need to be similar to the mains, or aligned somehow, or that timing matters. No. Wrong on all counts. Sure levels need to be matched. Yes its nice being able to adjust phase. But nothing remotely like the way the mains require precise placement. Low bass is a whole different animal.

Big subs are great. When it comes to the lowest frequencies, you probably cannot have too big. But you sure can have too few. Until you get to four, that overshadows everything.

"Low bass is a whole different animal."

Yes! I'll grant you that. It's only where I (or others) try to integrate at a bit higher than typical frequencies (like 170 Hz and at 1rst order) does it seem to complicate things. In my own setup, if I deliberately mis-adjust the delay, for example, I can Easily hear it at the lp.

Ivan, while the controls on the Rythmik Audio plate amps (Danny sells the Rythmik A370 amp for use with his paper-cone version of the Rythmik 12" aluminum-cone woofer, but the amp was designed and is built by Brian Ding of Rythmik) indicate that low pass filtering is possible up to "only" 120Hz, the amp is also available in a special version which has been modified by Ding for use in the OB/Dipole sub; that is the version of the amp which provides output up to 300Hz. Kind of confusing!