Re: Subwoofer poll
Sorry for such a late reply, but I was involved in leaving my job, selling the house and moving here to France!
In the UK listening room 4.7m x 4.7m x 2.3m the wall-installed subs were built to help me to enjoy organ recordings. They extended the bass down to around bottom F which improved the overall sound but due to my crude attempt at an active crossover, fell short of my ideal. I don't have that problem with the B&Ws and my new Bryston Amplification.
In the French house, the room is not much different in volume being wider but less deep and has a much "brighter" acoustic. It has a suspended wooden floor instead of the UK concrete. This makes the floor almost acoustically transparent to deep bass, which can be felt as well as heard. With the ASW750s there is a reasonable output down to around bottom D which is fairly awesome at times!
The quality of the extreme bass is very good, there being very little "hangover" on transients which allows a good reproduction of orchestral bass drum and suchlike, and of course 32 foot organ pipes! The built-in crossover in the ASWs I've set at 80Hz which seems to work very well. and until something very deep sounds, the subs are un-noticeable.
The integration between the Harbeths and the B&Ws seems, to my ears which are ageing a little now, very good.
"If all else fails, read the instructions"