I appreciate the replies. I don't think an ordinary equalizer can do what I'm asking for.
I installed Foobar2000 and within just a couple of taps I was stuck on a page with no way out...even if I Quit the app and re-started it...so I've Uninstalled it. (I told the app that I already had music on my phone, but did not ask Foobar2000 to scan it before continuing to the next page...which became the page with no way out.)
Are there other suggestions for a music app with compander capabilities?