HPF (High Pass Filter)

As the name suggests this switch cuts out the
very lowest frequencies of a sound whilst
allowing the higher frequencies to “Pass
Through”. It’s particularly useful in live
situations to reduce stage rumble or microphone
‘popping’, which can produce a muddy mix,
or to ‘clean-up’ male vocals and filter out low
frequency hum. Some manufacturers may
also use the term “low - cut” filter to describe
the HPF.