High-Pass in Daily Practice

Set the corner from the lowest useful note of each part instead of cutting every track at 100 Hz.

Related

EqualizerBusVoiceDrum Kit

The problem

High-pass filtering has become a reflex: cut every track at 100 Hz. The wrong corner thins a male vocal, removes the floor from a piano, and leaves drums with nothing but clicks.

Goal and judgement

Find the lowest frequency the part actually uses, then remove rumble and unused lows below it. Judge by sweeping and matching level, not by preset. Vocals often start between 70 and 120 Hz, guitars between 80 and 120 Hz, cymbals between 200 and 400 Hz, but arrangement decides.

Method

With a 12 dB per octave slope, raise the corner until the sound clearly thins, then back off 20 to 30 Hz. Keep Q near 0.7 and match level before comparing filtered and bypassed. Be careful with a master high-pass unless the whole mix has DC or subsonic content. When fighting bass, filter the accompaniment before filtering the bass. After filtering, hear the full section to ensure the low end does not drop out when bass enters.

What to listen for

When chest weight disappears as the corner rises; whether the mix turns muddy when the bass enters; whether bypassing the filter only makes things louder.

Common misconceptions

That every track needs a high-pass; that a higher corner is cleaner; that the filter only affects low frequencies.

Sources

• Bobby Owsinski, The Mixing Engineer's Handbook, EQ chapter — background checked, not quoted
• Udo Zölzer, DAFX — Digital Audio Effects, filter section — background checked, not quoted

Used for fact-checking only; all prose is original.