I actually hadn't even seen the current Equalization filter article when I spoke before, but now see that its content needs to be merged into the future article Equalization (audio) that you both have proposed. I could make the issue a little more complicated though: Graphic equalizer (not yet written), Smiley face curve, Parametric equalization, and British EQ all have to do with what I'll call "Music equalization" (for lack of a better term). This includes sections 1 and 2 of the current Equalization filter  along with possible future articles tone controls, loudness control (combine with Smiley face), speaker equalization etc. Oh, I'm certainly not saying that these need to be separate articles, but could as well be topics in one article (except that a few of these already exist separately). The article should mention that "equalization" is a misnomer (but has become the accepted term) since these are typically used to modify the tone to suit someone's taste, not strictly to compensate for a channel's frequency response.

Then there should be an article which discusses actual channel equalization (or some such term) which WOULD include section 3 of Equalization filter (Telecommunications lines), RIAA equalization, FM pre/de-emphasis as well as equalization of non-audio channels; this is the orginal meaning of "equalization"). Such equalizers are generally non-adjustable (by a user, at least) and transparent to the end user. So I call it a different subject, even when it IS audio. Anyway, I don't have much time to deal with this nor am I the best person to write about the specialized issues regarding either professional audio or channel equalization problems. (Though I'd be very happy to review what is written and check for errors and missing issues. Come to think of it, I don't have to ask for permission ;-)