What percentage of audiophiles use a sub ?

Tigger,

I will just add that I do think adding a well matched powered sub or two to monitors is quite capable of doing it all well and often at considerably lower cost than most single box full range speakers combined with similar suited amplification needed to match a powered sub.

Plus from the perspective of setup flexibility and convenience, a separate powered sub for the low end helps a lot. Proper setup in the room is key to performance. Often there are things that prevent people from accomplishing optimal setup with big massive single box speakers in many situations. They are just too heavy to move or experiment with easily so people do not bother as much or the placement options within the room is just too limited to get it all right including the low end. When this is the case, there is a very strong case to be made for offloading the bass performance to a dedicated device (a sub) designed to handle only that.

Also, yes, good monitors (and also perhaps a good set of headphones) are often just what the doctor ordered for apartment dwellers.

It is all a matter of critical system matching between components and taking the time with the room set up. There is much music in the 80hz region and below, not just movie soundtracks. For those who have a powered sub(preferably 2)that has the connection choice of rca in or speaker level in, I find the speaker level in is much more coherent with the mains. I learned this from Pierre at Mapleshade many many years ago. The quality of the speaker cable is as critical here as with the mains. Crossing over the mains or running them full range is also very system/listener dependent. I run my mains full range and have the bass systems from 60 hz down. Adds another level of musical realism to these ears......

Eliz -- I can vibrate my internal organs with frozen section tacos !!

I believe there are a couple of issues with subwoofers in a 2 channel configuration.

First, many people don't purchase subwoofers that match the sound quality of their main speakers so it's essentially putting a $200 bass driver in a $3,000 speaker (just an extreme example). The salesman at the store that I deal with indicated that the current JL Audio subwoofer were on the short list of "audiophile approved" subwoofers and is about all they have in the store for the high end customers.

Second, every amplifier has its own sound and if an active subwoofer is used it isn't likely that it will perfectly match the sound of the main speakers. An audiophile isn't likely to hook up left and right channel speakers with different mono-block amplifiers and many, I suspect, wouldn't bi-amp speakers with different amplifiers either.

In my case, my receiver forces me out of direct mode to use a subwoofer so for 2-channel critical listening the best configuration is two full range speakers. My Focal 836v speakers can reproduce 30 hz, but not at a loud enough volume to support home theater applications. I have a subwoofer that isn't an equal with my main speakers, but does a wonderful job of the .1 duties and for heavy bass non-critical listening.