I had the same with my M100's where the filler driver rattled - I took it to a repairer in Norfolk and they were very good, although it did take some time - but whatever you do don't through it away. Like you I was astounded when I switched from a Beomaster 6500 diriving them to a tube amp - now they are driven by a BM4400 as I found having no control over the bass to be a problem - they sounds amazing now, so I imagine a BM8000 on yours would also sound brilliant.

It may have been this company http://www.audioloudspeakers.co.uk/aboutus.shtml

Interesting - so are you saying the 4400 sounds better than a 6500? What tube amp were you running - were you getting enough volume and bass?

I'm running the MS150s with a tube amp I bought new in Hong Kong some years back - all of $120 worth. It really does sound fantastic other than a lack of bass, which is something I'd like to address. I have tried various solid state amplifiers and the sound overall just doesn't sound close to the chinese tube amp.

Hi - I can't remember the make of the tube amp, but it was Chinese and very substantial - the bass was amazingly deep - a bit too deep though as I have wooden floors and you could feel the bass in the other rooms. It output 40watts which is plenty. The bass was too much hence moving back to a B&O amp where I can control it. The 6500 I always sounded slightly wooly, not bad sound but not full and engaging. The 4400 to my ears anyway is much just so much better. The other problem I had was humm from the turntable as I tried several different preamps, with the 4400 there isn't any and the 4400 also has tape inout and outputs whereas the tube amp didn't.