You're getting a lot of bad advice. It's well meaning, but it's bad. Ask all those people who are bashing the Krell whether they have actually heard that model?
If you still have the iMac, download Channel D's Pure Music, the trail version is free, and use it with a software EQ program. Also, did you try the mods to the Benchmark that were previously recommended?
If you still have the iMac, download Channel D's Pure Music, the trail version is free, and use it with a software EQ program. Also, did you try the mods to the Benchmark that were previously recommended?