Mix Bus EQ

Many mixers typically use a HPF to roll off <30Hz on the mix bus. Some also roll off 30Hz on submix buses and individual instrument channels. So my question is, if I've rolled off <30Hz on the mix bus, why do people repeat that on group buses and individual channels....is the mix bus cut insufficient to cover everything? This is a point which may well reveal my ignorance of electronics! Thanks.

It's often beneficial to remove lower frequency from an instrument that doesn't contain them naturally (such as, say, a vocal) to make sure they don't trigger dynamic processing such as a compressor. So for example you wouldn't want low frequencies generated by the singer softly tapping his foot, or his t-shirt brushing against the mic stand, or some weird breathing .... to trigger his compressor.

Ok that makes sense, thanks David. So what I think you're saying is that a mix bus EQ cut will not feed individual channels before they are subject to other processing.

Ok that makes sense, thanks David. So what I think you're saying is that a mix bus EQ cut will not feed individual channels before they are subject to other processing.

 

Mix Bus EQ is the last bastion of filtering. doing a high pass on it can change your mix radically.

It's better to do a high pass on individual channels that contain low frequencies you don't want. That way everything that gets to the Mix Bus is already "pruned".

Ok that makes sense, thanks David. So what I think you're saying is that a mix bus EQ cut will not feed individual channels before they are subject to other processing.

Yes, exactly.