"unpleasant to listen to" and "edgy frequencies" are sure signs that you are either using cheap gear or the drums themselves just sound bad. Or, arguably more important, the player could just suck. It's probably obvious, but that is really the place to fix it, if you can.
By all means try removing those frequencies, you don't need our assurence there, and we really would have no idea because we have no idea what it sounds like, other then, I would assume, crap. You can also try short delays or reverbs to add power and/or smooth out the edgyness. Most cheap devices will surely add harshness so beware! Some people have bounced drums down to tape and recapture it, a more natural effect when done properly. Anything you do though will more then likely make the drums sound worse, so it may be a matter of keeping them lower and just dealing with it.
Somethine else you could try which may work better is keep the drums low so the cymbals aren't annoying, if you have snare/kick/tom tracks, set a compressor on them, or send them to an aux channel with a compressor, and make it so they 'pop' only on the initial transients. You'll want to play around with the attack/release settings of course, but you should be able to make them sound more dynamic. If they become harsh, throw a EQ on it. If you have this as a aux channel that may be nice, because you can blend it in with the mix better without having to change the overal drum level.
Hope that helps, there really is alot other suggestions, but they are all 'band-aids' and should try to be avoided next time.