The High-Pass Filter: A Church Sound Board’s Most Underused Button

Why should I use a channel’s high-pass filter?

There are mean nasty ogres that live in the lower frequencies. They walk around the stage speaking in tones so low…”how low are they?“

They are so low that they sound like deep earthly rumblings. And when the hpf isn’t engaged, you get all those rumbling in your sound system.

Wait a minute, that’s not the whole truth! If they were there all the time, wouldn’t there always be a filter at that frequency? True indeed.

Frequencies in that lower range can be both good and bad. Kick drum, bass guitar, Froggy from the Little Rascals – those all work around that range.

However, a tenor’s vocal microphone that picks up the kick drum on the stage…not good. It’s in these areas you start using the high-pass filter.

Rules for using the high-pass filter.

Rules in audio mixing are few and far between. Guidelines are more the terminology but when it comes down to it, if it sounds good then it’s right.

With that in mind, there are times when I’ll engage the hpf for a guitar and times when I won’t. There are some simple guidelines you can follow;

—If the microphone’s source sound doesn’t use those lower frequencies, then engage the hpf.
—After setting your basic mix, engage the hpf on channels and listen to the difference. Pick the best setting.
—Experiment. What if you engaged the hpf on a bass guitar and it gave it a unique sound that fit the song? Try it!

Conclusion

The high-pass filter channel button shouldn’t go untouched. It’s one more way you can clear up your mix and provide the best sound possible.

Chris Huff is a long-time practitioner of church sound and writes at Behind The Mixer, covering topics ranging from audio fundamentals to dealing with musicians – and everything in between.