My current amp is a Yamaha DSP AX620, DVD player ia a Denon 1400 and these worked very well with my old speakers which were Eltax Millenium. My problem has arisen since I bought a set of Bose Acoustimass 6 speakers to replace the Eltax. No matter what I try I cannot get the dialogue through the centre speaker as loud as my previous set up. So far I have decreased my main speakers to -10db and the centre speaker to +10db and still the speech lacks impact. Does anyone have any ideas?