1 or 2 subwoofer for small room & placement


I have read that 2 sub-bass systems will yield better results compared to one in 2-channel stereo setups. Is this applicable to a small room of say 11.5'x17'x9'? Or one sub will probably be more than adequate and yield better results compared to 2 subs which may be too much for a small room?

I know experimenting is the key, but if sticking with one sub, which is the most preferred placement that will produce the best results? At the extreme corner of the room close to wall boundaries, or in between the main speakers at the middle in almost free space? I have tried both and slightly prefer the sub in between the speakers in free space. I'm curious to know which configuration is mostly adopted.

Lastly, are the active crossovers in the REL Stadium/Stentor subs made of high quality parts for use in high-pass configuration(in rolling-off bass to the main speakers)? Concern is with the sub's crossover inserted in between the preamp and power amp that may sacrifice sound quality if it's of inferior quality.

Any advice from knowledgable folks would be most appreciated.
ryder
Corner placement of one sub can smear the soundstage; the higher the crossover freq the more it can imbalance. For my room the most musical location is centered between the speakers and with almost same distance from front wall as the mains. This enhances soundstaging and still good two channel bass. For home theatre and movies corner placement will give most impact. For music best arrangement for corner placeemt is two subs.
2 subs will load room better than 1.Most of my subs end up between the loudspeakers.
Thanks for responses. Looks like I'm not alone in getting better results with the sub in between the speakers. Just purchased a Radio Shack meter and would be curious to know how things can be improved even further.
I use a pair of Vandersteen 2WQ subs with Thiel CS2.4 mains. I don't know about other subs, but the 2WQs are tunable (volume and Q) and they mate very well with the 2.4s.

The effect in my system was not subtle. Yes, the low frequency material was there with good authority, but the sound all the way up through the midrange was cleaned up and tightened up; better timbral accuracy. Also, which was a surprise to me, the overall imaging and soundstage were much improved. These are qualities that Thiels are known for on their own anyway.

With the 2 subs its a whole new class of speaker system. Like I said, my impressions are solely in reference to the 2WQs.

In regard to placement, I think just put them where they fit best and tune them to that position. Mine are a couple feet behind my mains.
In my large room, with 7 channels, I have the main L/R mounted on top of 15" subs. This, in effect gives me 4-way mains. Works great for HT and multichannel music.

But in my smaller room, that has a turntable setup I only use one sub, which is in between the two speakers.

In the first room that I ever used a sub I had the sub in the front corner. That room had bad standing waves, due to a steep vaulted ceiling, that topped out at 15' and the wall then dropped down to the 8' level.
So it really comes down to what the room needs.