Two Subs?

As one who lacks PSM ego (tho I've got more than enough of the garden variety sort to offend most folks), I do use room correction. Attendant to that task, I've generated tons of readouts from my RTA that show FR at the listening position. Two subs generally produce notably better "looking" readouts at the listening position than one sub, prior to EQ. After EQ, two EQ'd subs probably produced better results than one EQ'd sub over a wide area - tho results at the listening position were awfully close. I say "probably" because the comparison is really dependent on how you define the "wider area".

I also emphasize "better looking" than "better sounding" only because the latter is subjective. However, to my ear, the results definitely correspond to the readouts - I much prefer the articulate bass sound of smoother FR at the listening position. IME, smoother response comes with multiple subs and/or room correction.

Just my own experience, FWIW.

Marty

PS - re: Bob's comment on the high level REL x-over scheme. There are advantages to inserting an active x-over that you forego when using REL's scheme. Believe what you will regarding the claimed benefits of REL's scheme, I'm pretty sure that Bob was expressing his own strong preference for actively crossing to the subs ahead of the power amp.

Sub measurements schmeasurements! I get lots of clean bass, because if I didn't I would be unhappy. Unclean bass indeed! Not sure what "smoother" sound means, but whatever I'm getting from my little REL seems smooth...I think it's dialed into maybe 58hz or something so it's actual low end only to maybe 25 hz (I measured it...so sue me!) before it gives up the ghost. I've measured my listening room using digital real time analyzers with various serious stupidly expensive pro cardioid mics, active and passive pro EQs both graphic and parametric notching types, and other stuff to play with my room system, and I prefer none of the above in the system as it seems cleaner without it. I simply turn the REL up or down...a teeny bit...ahhhhh...perfect!

Back when I had the REL Storm I was getting much better bass response than when I didn't have the sub connected. No question it sounded, and measured better with the sub on. But there was no way around certain room modes, despite trying several diferent locations within the room.

With the two Rythmik subs well placed and dialed in I get much better sound than with the REL, at least for my taste. It took many iterations of placement and dialing in all the variables in the sub's amps, but well worth it for me. Frequency response is much smoother as well, and I was able to significantly reduce the impact from those room modes that were affecting the response so much. To me, this configuration sounds much better than the one with one REL.

But I don't have experience with active crossovers, although I've been toying with the idea of actively tri-amping.
Bob, what crossover do you use? Conceptually, having one amp for mid/highs, one amp for the bass drivers, and then the two subs running in mono makes sense to me, but trying it at home would be expensive.

I've always found room modes to be an issue with a single sub, ie very noticeable by ear variations in bass levels at different room locations. Also I find that it is possible to address to my satisfaction as long as listening position stays the same. I am confident the more sophisticated and complex eq solutions have up side as well, but not critical for me personally. I would prefer to have two subs rather than one though to help smooth out things within the room better and would probably go down that route next time, though I could probably live without it quite fine just as well as I have managed to do in the past.