Add a 3-Band Kill EQ

[Daniel Schürmann]

3-Band Kill EQ is the most common EQ found on Hardware mixers.
It does not offers full kill, but allows better tweaking of the sound.

This could be interesting for use case where you like to tweak the sound individual for each track rather than tweaking the system sound by the master EQ.

An example of this EQ is the Xone:23 EQ

[RJ Skerry-Ryan (rryan)]

How is this different from our existing 3-band EQs? They have always been "kill" EQs (e.g. turn all 3 knobs to the left -- sound is ~totally gone). The channel EQs already allow you to tweak the sound individually for each track.

[Daniel Schürmann (daschuer)]

All three EQs which we have right now are actually not EQs. They are isolaters build from crossover networks. These circuits are normally found in speakers to isolate the sound for a three way speaker.

This will now be a "real" EQ with simple one pole filters.
The kill nature is referencing the kill switches and the feature that it allows to suppress the center frequency to -26 dB. You cannot make the sound totally gone.
IMHO it is more an advertising verb of Hardware manufacturers.

The benefit for us is: Bit perfect at unity + very low CPU + cautious sound tweaking + known sound from hardware mixers.

[Be (be.ing)]

https://github.com/mixxxdj/mixxx/pull/1129

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/8764