Dual subs and room size

What wattsperchannel said.

Get two used subs . For a g you can score rythmics,svs  little more and you can get two hrs sunfires i love mine . I started with one and honestly the places i could place it i heard it or i had bass issues. Added another and its less placement oriented .  I run pre outs to mine and once again that interconnection choice made a difference.. jmho 

While we're on this subject, I have a question. Did I read someplace that newer stereo releases are being mix/mastered for separation down to 20Hz (and below)? Would this be a good reason to go for two subs?

There are several industry experts which will only recommend 2 subs in a 2 channel system.  George Vandersteen and Jim Smith to name a couple.  To the point they state, for a 2 channel system,  they would not add a sub to the system until they had 2.  In my own experience,  I owned a single JL Audio F212, and I was never able to get it to blend right with my speakers,  and I felt it took away from the imaging of the main speakers.  It wasnt,  due to lack of trying, I worked for weeks on sub placement and in different rooms with different speakers,  B&W 802D2,  Revel Salon 2,  Aerial Acoustics 20T V2.  Rooms all treated.  After researching,  ultimately bought a second F212 and was blow away by the improvement.   In fact,  I didn't tell my wife I bought the second sub and was playing the system, she said,  "wow,  that is sounding really good".  What did you change?"

Corrcting myself.  It is Richard Vandersteen, not George.