does a subwoofer kill stereo sound?

Ohjoy40...I respectfully disagree with your comment. The bass that comes from a sub IS perceived as mono..whether stereo recorded or not. Bass is non=directional. What makes it seem like stereo, are the overtones, not the 30 or 40 cycle fundamental. These overtones are reproduced by the regular speaker, and thus seem directional. There is no need to spend lots of money on a "state of the art" amp to drive a "state of the art" sub. The built in "usually" class D (big power vs small size) is very good...the sub has a very limited range, without need for those subtle nuances we all love to listen to on our full range speakers.

Regarding soundstage... In my own experience adding a subwoofer seems to perceptually expand the soundstage, particularly the depth. Larry Greenhill has mentioned the same effect in his subwoofer reviews for Stereophile.

This is exactly my experience.

Further, some of the assertions made in this thread seem to be based on a "perfect world" basis where we have unlimited funds, and unlimited flexibility in our listening environment. I think when you allow for the fact that this is rarely true for most of us, a subwoofer will provide a more optimal imaging than the alternative full range floor standers that may have limited low end due to budget, or sub optimal placement due to room limitations.

Re: expanding soundstage.

I've heard the same effect, but not consistently. Most recently it's become quite apparent on Allen Toussaint's "The Bright Mississippi" which I believe - and I am speculating here - features a very large bass drum. With the subs on-line, the recorded acoutic sounds much larger when that drum is struck.

However, I rarely hear this type of dramatic evidence of this effect on most other recordings.

Marty

OhJoy,
Isn't bass mixed to mono below.....say 80hz?
Also:
Given that bass wavelengths are longer than the longest dimension of MOST rooms, I'd say a sub was not locatable, eyes closed.

In large rooms, this may change.