Where your low string actually lives.

Every heavy tuning puts the lowest string's fundamental somewhere between about 49 and 82 Hz. That number matters every time you reach for a high-pass filter.

E Standard	82.4 Hz
Drop D	73.4 Hz
C# Standard	69.3 Hz
Drop C#	61.7 Hz
C Standard	65.4 Hz
Drop C	58.3 Hz
B Standard	61.7 Hz
Drop B	55.0 Hz
A Standard	55.0 Hz
Drop A	49.0 Hz

Equal temperament, A4 = 440 Hz. This one is maths, not a measurement.

How to use it

A high-pass above that number cuts the string itself. Sometimes that's exactly right: the bass guitar carries the fundamental and the guitars make room for it. Sometimes it's how a riff loses its weight. Either way, now you know which one you're doing.

Next: The heavy mix frequency map.