Single vs. Dual Subs

For two channel stereo the best to the worse is: A pair of woofer towers, a pair of front firing subs, a pair of down firing subs, a single front facing sub, one down firing sub.

I would say that with dual subs you can have stereo bass if you mount them in the same plane as the main speakers if you use a single sub you need one with a blend circuit and again mount it in the same plane as the speakers both types work well for music but finding a good single sub with a proper musical sound is more difficult. Same plane is no more than two feet forward or back from the main speaker baffles.

Thank you all for sharing your experiences, seems like a majority of people have seen great benefits going with two instead of one. I will go for two for my 16x23 room and report back.

carlsbad, I have been using ESLs for over 40 years and am very familiar with the CLS. When you get the second subwoofer get a two way crossover. Rolling the bass off in the CLS's will result in a very large improvement in distortion and headroom. You will easily get another 10 dB out of the system. Cross up between 100 and 120 Hz. I would use a Mini DSP to do this. That way you can use steep slopes and you can time align the subs to the CLS's which is very important. You will soon realize that the crossover is the single most important piece of equipment you have. Also, do not put the subs behind the CLS's put them outside the CLS's preferably in corners right up against the walls. They are an easy 6-9 dB more efficient in this location, the sub does not have to work as hard and this lowers distortion.