Using two subs

I went form using one to two subs. The obvious benifit is of course more power and more apeaker. But I really can't explain it. With one sub I had bass. With two subs I have the instruments that are covered by subs. The bass appears to come form my main speakers.It's like they are not here.

Thanks for the responses so far. A little more information about my system and the potential additional sub.

Room:15W x 20L x 8H
Full 5.1 currently: All full range (Klipsch 3-way towers)
Current sub: Klipsch RSW-15 (650watts 15" passive rear firing)

I am thinking about adding a REL Stadium III for the second sub. (200watts 10" ported down firing)

A few things I like about the REL: local purchase, can be integrated easily with my 2 channel setup, and hopefully will strenghten my lows for HT.

One reason I'm doing this is because I know that Klipsch speakers/subs aren't the best at the very low end.

Am I on the right path?

Gregadd,

Setup caused the problem you experienced with a single sub. A single sub, properly setup, should disappear as well. But setup may be easier with two subs. Don't know about your subs, but I have mine turned down to a quarter scale at the sub and use the pre attenuator to match the 5.1 levels with white noise and my RS SPL meter. It can generate that felt vibration with a low pedal note or make you feel your chest is compressed with an explosion in a movie. So I doubt adding power is the reason for a second sub.

db

I went from one revel b15a to two and the difference is FAR from small.
Even though I could not hear where the sub was I could always feel the "pressure" on one side of the room was more. Adding a second sub has evened the pressure as well as aided me to level the bass response out in the lower registers.

I would never go back to one sub having lived with two now.

GO HERE:

http://www.harman.com/wp/pdf/multsubs.pdf

I run a pair of subs and won't ever go back to single. Once my system is set up as I want, I will set up my subs to carry the LF of my mains and LFE at the same time. I do not hear my subs at all but definitely feel the LF. One day I may even EQ the subs for optimization.