Request: low - and high shelf filters

[nofishonfriday]

Hi,

would it be possible to add (frequency adjustable) low - and high shelf filters?
They are very common on HiFi amps ("bass and treble knobs") and imo very useful for e.g. reducing bass overall.
But surprisingly missing on (almost?) all Android EQs.

The headphones I currently use are too bassy (and a bit too much high end) and I use kind of an approximation of shelf filters within the arbitrary EQ which works but frequency response is not as smooth as with real shelf filter.

Thanks for considering and your work on RJDSP.

Arbitrary EQ I'm currently using:

vs