Subs and the quest for bass.

I see that I dropped one sentence re: my specific set-up.
I always sit in 1 spot - no variation. If you move around in your listening room, the second sub will definitely provide benfits vis a vis an EQ'd single sub.

Marty

Nemesis,

As you probably know, I use exactly the same set-up, but with 2 Rythmiks. If you go this way, you will definitely reduce the amount of EQ you deploy but:

1) I didn't hear much/any difference between a single sub and dual subs with the SMS. The amp in a single sub never sounded remotely taxed by the EQ'd signal, so I was never aware of the EQ being applied. Partly, of course, this is the result of the EQ needed for my room which may differ dramatically from yours. If so, all bets could be off.

A single sub just sounds neutral, powerful, and perfectly integrated in my set up. One sub was enough, but I started with two and decided to stay that way. Doesn't hurt, but - honestly - it might well be overkill.

2) The SMS is still a great tool for dual subs. Even though the "native" response of dual subs is much, much smoother, I still use 3 bands of EQ to address meaningful deviations in response. However, it's the "fine tuning" with the SMS right at the x-over point that really makes a difference. One sub, two or even four, the SMS (or equivalent) is still the best customizable subwoofer high cut that I've found.

The good news is the the Rythmiks are money back - so you can try a second one on their dime. Just don't expect a lot of impact.

Marty

PS Make sure that you experiment with the Q setting on the Rythmik - it does make an audible difference.

Nem,

If you're looking for the least EQ, my guess is that the corners wide of and behind the speakers will work well. I tried pretty much every combo of corner/corner, corner/midwall, and midwall/midwall (note: my room has no wall behind the listener). Some were slightly better than others, but there wasn't a ton of benefit (as measured by the SMS' RTA function) to any other location and the corner placement is symmetrical and eye appealling. OTOH, you will almost certainly see deterioration in the native (non-EQ'd) response if you pull the subs away from the wall and place them near the speakers.

Good Luck

Marty

Nem,

I understand your point. Take a listen. Take a look (at the SMS-1 readout). Both will confirm that near wall placement (at least IME) yields much smoother response (pre- EQ).

If you don't care about the amount of EQ, it may not matter. Put the subs where you want and EQ them to your preferred response. If you want to minimize EQ, the subs will (probably) have to be against the wall. Corner placement raises the overall output level of the subs, meaning you'll be optimizing response for reducing peaks rather than boosting troughs, generally IME a good thing - though probably not essential with dual Rythmik 12 inchers in your room.

BTW, if you're crossing below 100hz, I don't think you'll hear any impact on imaging (at least, I don't) relative to sub placement. As your crossover point moves north, well....

Best of luck with the project.

Marty

Nem

Subs are behind and wide of the mains and crossed at app 75 hz. No delay applied. Overall, this is the best bass I've ever managed to achieve. Zero complaints and integration is seamless. Blind, I would never guess that there were subs in this system

Good Luck

Marty

Sorry I should have mentioned that the subs are app 3 feet further from my listening position than are the mains (13 feet vs 10 feet) and maybe 4 feet wider apart in total.

Marty

Nope.
Summed with common EQ. Works fine (for me, anyway) when crossed at 75 hz.

Marty

Nem,

I've thought about the "how to" issue with stereo subs and a pair of SMS-1s, but never actually tried it, so I can't really say. At these low frequencies (i.e. crossing below 100hz), I really don't think that you'll hear any impact from stereo subs.

If you want to test that theory, find a highend HT store that will set up a pair of subs for you in a way that allows you to kill the main speakers and listen to the subs alone. Then have a shot at the balance control. I tried (a variation of) this test and decided that stereo subs didn't matter to me. Of course, YMMV.

BTW, I'm pretty confident that the SVS/Audyssey does true stereo/independent channel sub signal EQ which solves the issue.

Marty