When using the Side-chain HPF for example, the manual states that "a cut filter offers attenuation down to -15dB". Does that mean that the filter drops the level of the signal 15 dB at the selected freq? IOW, the roll-off starts at a higher freq than the selected freq and reaches a drop of 15 dB by the time you get to the selected freq?

Also, what is the slope of the filters?

Please clarify...
Thanks.

Those s.c. filters are shelfs, they can attenuate by 15dB in the stop band, not in the pass band.
As they are shelfs there is no usual slope like for high/low cut filters, however they are usual 2nd order IIRs.

Regards,