Would you install THIS on your iMac?

This is a user-to-user support forum, and we'd be able to help you if you'd already installed it and you were having issues with El Capitan as a result (for an example), but you can't ask us whether or not you should install something, or whether or not we should install it ourselves. Only you know whether or not you should put something on your computer.

<Edited by Host>

Why would an US site be any more safe? (Just asking.)

I'd question the site, it's got more ads on it than it does content and it knows about what I do in the internet! ($50,000.00 hasleblad cameras and guitar neck refits, neither of which I can afford)

If you want to re-engeer a song because the people in the studio were idiots and didn't overwhelm the mix by saturating it with all audio signals below 20K I suggest reading these articles

https://discussions.apple.com/

http://osxdaily.com/2012/05/18/equalizer-for-all-audio-mac-os-x/

http://www.globaldelight.com/boom/index.php

my $0.02 disclaimer:

Any issues you may encounter should be taken up with the developers in the event you have one, anything you decide on is of your own volition.

If you don't mind, please direct me to the forum rules so I won't make such an egregious error in judgment again.

https://discussions.apple.com/docs/DOC-6082

Also: https://discussions.apple.com/docs/DOC-5952

Take a look at this first, I don't think the program is "unsafe" but it does seem to have some problems with El Capitan.

http://www.bitgapp.com/eqmac/#feedbackDiv

FWIW, I use Hear.