Subwoofer for classical music listener

I just fine tuned the bass of the sub by a method that some people might find useful.  Like, I'm sure, most new subwoofer owners, I had  the bass tuned higher than I should have.  Then I listened to two records of a classical symphony
 ( Mozart's 39th in Eb.)  By finding the balance (equal volume) between upper (violins) and lower strings (cellos and basses,) I got the best quality of sound.
I then tested many other combinations of instruments (including organ) and styles  (including jazz) and found everything to be in balance.

rvpiano-

I too, have the constraints of the system among a living space(no dedicated room)

My 2 sub configuration has BOTH subs equidistant to floorstanders  BEHIND the listening sofa-long walls. 
This pressurizes the room in a convincing manner. Bass envelops the room-but not is an obstrusive way. You end up dialing back the settings, as the subs work less.

As an aesthetic benefit, no unsightly giant boxes behind the floorstanders.
I have them on brass footers/4" maple slabs also brass footers(Mapleshade)

A single sub in my room was fine, but the second eliminated a room mode,also changing the very lowest of bass tones(slightly mushy) to a clearer,defined more convincing presentation. Finding the 2nd sub for cheap was the only reason for even considering the sub. I was happy with the single REL.

As a side note,  the 1812 Overture WITH cannons is glorious. A visceral experience-almost as if you're standing next to them!

Happy listening.

Tablejockey:  When I'm ready, I'll start experimenting with two subs.
I can see I'll have to get creative in setting them up.
It would probably be an improvement over one.
So far, though, I'm delighted with the one I have.

Happy listening to you too!

Upon extensive listening, I've discovered that, although I love the sub, there is a definite coloration and lack of precise imaging when listening with it on. It's wonderful for selections with low bass, but in pieces with complex harmonics it doesn't quite have the "magic" that the unadorned system has.
But, it is a lot of fun and quite exciting and I'll be listening to it much of the time.
I can see an integrated system with both qualities would require me to get a whole new setup and cost big bucks.
 I'm very happy the way it is for now.
Its giving me options I never had before.

You might not have it  dialed in quite right. Some of the imaging problems come from the single sub. you have both channels mixed together which cancels the ambient and phase signals coming from the low frequencies for both Left and Right channels. Contrary to popular belief, there are signals down in the low frequencies that will give clue to direction and space.