If you'll click here you can find the frequency response graphs of each EQ setting. This was measured coming out of the radio (at the Bose amp connector) with the tone controls flat and the volume at maximum.

What the graphs will show you are the center frequency and the amount of maximum boost or cut at that frequency. Keep in mind that this omits the EQ that's located in the Bose amp.

Robert Cheng
'00 S4, 6-spd, Stasis Tracksports 650/750, MTM Exhaust, Autospeed DP's, Stoptech 332mm, UUC SS, UUC ADS, 19mm sway bar, SSR Comps 17x8.5, Istook camber arms, AWE Stage 3 (GIAC, K04's, AWE intercoolers, AWE exhaust manifolds, AWE LWFW, hybrid RS4/Spec clutch, AWE fueling), Stasis 4:1 center diff, Samcos