one or two Sub-woofers?

I would recommend getting one of the better one. The quality of the bass is more important then the quanity.

But then down the road I would upgrade and add a second one. Of all the upgrades I ever made to my system adding a second sub was one of the best. Better imaging and seperation and was more like a cable upgrade then just adding more bass. I was also suprised in how much it cleared up the sound.

One of the most important qualities for a sub is good intergration. The key in getting this is to at least match the quality of the bass with the quality of the treble. Anything less will make it sound like you added something and not just made everything better. Your system is only as good as its weakest link.

Martin Logans have some of the best treble I have heard and if you really want the subs to work well you are going to need great quality bass. Two subs do add a lot of benefits but what good is this if the quality of your system goes down.

I tried to add a $800 center speaker to a $11,000 pair of mains. The center sounded great when matched with equvilant mains but in my system the quality was so different it was more of a distraction even though it added a lot to the overall sound feild. Although this example is to the extreme I think in a much lesser degree it works the same with subs.

I tried many subs and the only one that wasnt a distraction was a Rel Stentor 2 even compared to two lesser rel models. Later I added a second Stentor and got the best of both worlds. Dont sell yourself short on a sub especially after buying such great speakers.