I have the following setup : Fronts : Eltax Symphony 8.2 floorstanders Centre : Eltax Symphony Centre Rears : Mission 760i Amp : Yamaha DSP-A5 When I use the test tone to check my speaker levels, the tone travels from front left - centre - front right - rear right - rear left. When the tone reaches the centre, there is a slight increase in pitch when compared to the other 4 speakers. As the fronts/centre are from the same range, I would've thought that they would be well match tonally. Is there something I can do about this ? They are currently wired using different speaker cable, although I wouldn't think this would make a massive difference to tone/pitch.