2 Channel Sub Woofer, 1 or 2 Sub-woofers?

Hi All,

I am thinking of adding a sub woofer into my 2 channel system. I am looking at REL. Should I be thinking a pair of subs, of should I be thinking of a single sub?

Thanks guys for your ideas on this one.

If you were designing a (cost-no-object)speaker system having response to 20 Hz or so, would you choose to put one of the drivers in a separate enclosure located several feet away from the rest of the system? I think not. IMHO, each main speaker should have its own subwoofer...the driver which the manufacturer left out to lower cost.
two subs......there is a no brainer experience when you hear the difference, i waited a long time and wasn't going to do it, a friend who knows quite a lot said the bottom end was always in mono, but after adding the second one, wow , no going back unless as eldartford said....one speaker with proper crossover and all bottom end....do it....
Not to hijack the thread, but a related question I've been wondering for a while is if it came down to getting one very good sub vs. two decent subs for similar total cash outlay, which would you choose? Let's say one $1000 sub or two $500 subs?
Assuming you have freedom of placement, a pair of subs can yield a smoother frequency response. See the Harman papers:

Click on White Papers and then these two papers:
"Subwoofers: Optimum Number and Locations"
"Part Three: Getting the Bass Right"

Now whether you want to run them Left & Right summed mono or separate Left & Right is another topic. Actually, the first paper cited makes mention of this as well.
I tried both options described here almost exactly. One $1500 sub and 2 x $700 subs (same brand used all round) and went with the 2 subs. In my room and for my tastes, the 2 sub option sounded better, integration seemed more "right" and set up was easier - just put one beside each speaker.
I vote for 2ch stereo subs --like above have tried both ways and prefer the subs this way also for Soix if it was me I would get the better sub then save money and buy a second better sub
Take two.
Another vote for 2 subs. However, for me, the key was proper integration - hard to do without help. In my case, I use a Velodyne SMS sub controller for this purpose, but there are also other products with similar functionality. For instance, any of the Audyssey enabled products will help optimize X-over and eq.

After reading all responses here now I'm wondering whether to fork out another $2,500 for a similar subwoofer for my 2-channel system.

I have another $600 subwoofer currently relegated to HT duties due to its incompetence when compared to the $2,500 sub. Although I have not tried it before, I was wondering whether there would be a slightest chance that both subwoofers can be hooked up together as a stereo pair and give better results. Any advice would be appreciated.
I have used two subs for the last thirty years. Try to wave launch [time align] each sub to its respective left or right main partner. Its all about proper phase control. Tom
I like two also but if you have a chance at a single one used take it and wait for another. I have used one REL and it worked quite well. Also one REL Studio would do an excellent job if you wanted to put that much money into one.