Thanks Ajax,

The receiver in question is a Marantz SR8500 and it has 3 settings for the lowpass/ highpass filter that affects all speakers set to "small". 80hz, 110hz and 120hz.

Just so I understand, how do you relate the +/- 3db to an actuall frequency number ? for instance, if my mains are rated for 40hz, how do I calculate what + or - 3db is from that frequency ?

Thanks
Stephane

Acoustic Zen Adagio, Veritas center, Axiom EP500, QS8s, Anthem AVM20, MC20,Adcom GFA7400