so, after comparing the Grado 225 ($300), Sennheiser 590 ($300) , and the Sony 7509 ($320), I decided on the Sony's. They sound absolutely amazing and completely blew my mind, and possibly my eardrums temporarily. . I have to turn the treble up a touch, but the bass is unbelievable. I seriously can turn the bass up to the point it hurts my ears. Without any sign of distortion. On my Denon 3805, I have it on "stereo" with the treble at +3 and the bass at about +1. Some sources can take more bass. I had it at +5 last night on a few CD's and seriously it felt like I was listening to a subwoofer. I am a basshead, but also like detailed highs. These headphones are incredible. They are better I thought than the 7506's I tried in the store for a few minutes. The Sennheiser 590's were close. A little brighter. Very comfortable ...but the tonal balance on the Sony's won out. I am not a Sony fan per se. I may have paid more for the name but I will enjoy these so it's worth it..
JC