It's really a sort of gimmick - at least, the values for the settings are.
true, especially for SP, but bass roll off as a concept is not a bad thing to have access to
I am thinking of making one myself but with not such drastic roll off points.
They make capacitors (the things that provide the roll off) in values of .068, .048, .039?, .033, and .022 microfarads. Anyone can make the roll off selections more incrementaly even. I may try it sometime next month.
I was thinking that folks used them for other stuff like man-on-the-street-type of interviews where decreasing the bass will help isolate voices better.
.22 caps provie way too much bass roll off for music, IMHO, and I really don't like the cheap DIP switches that others use as roll off selectors. They aren't good enought for high fidelity recordings.
This could be quite a DIY project.