Hi everybody, I have 4 Tannoy Mercury M 2.5 speakers all round ( not sure if done the right thing having back speakers the same as front?) Now I need to upgrade to go with new amp (when bought, cant decide which one) Is it too much at the back to have 4 M2.5,s. Should I go for a different type for the extra 2 needed or new type for all the 4 back speakers? Last question is, do I definately need 2 back speakers for EX or is one enough. To use 2 I will have to keep moving to and from door position when in use. ( amp is either Pioneer ax-10 or the new Denon A1SR) Your help will be very much appreciated especially after getting through all the above questions. Phill.