Sennheiser HD 650's thin sounding?

I having the same experience with my "near new" HD650. I don't believe it is a defective pair. When compared to my well-used HD600, the HD600 has more bass, more extended high, more air, and bigger sound stage - almost better in all areas. I hope the 250-500 hour break-in period is true, or I will be very disappointed.

I briefly owned the 650s but sold them cause I couldn't stand them. Moved up to the Denon AH-D7000 and haven't looked back.

Yeah...I had them for much longer than 500 hours. To be blunt - they are piece of...you know. Even 50000 won't change them. Resolution is not bad but the rest of them is totally unacceptable. Cheapest Grado sound much better overall. Sorry.

Interesting posts.. I was beginning to think I was deaf.. my Senn 600's basically sound like c..ap. With the Musical Fidelity X Can they really are garbage compared to a decent system. I'm not sure if it is the X-Can or the combo, BUT they are so weak that i think any real listener has to be basically tone-deaf if they are recommending these 'cans as anywhere near hi-end! All those reviewers who think that these cans sound good should listen to my system and then tell me that. Pity as I think the Senn's are well made and they do feel nice to wear.

I have the HD 600s and find they are wonderful. I use the MG Head OTL headphone amp. For me they are better than any stereo system I have heard with more detail and nice weight and decent bass. I have more experience w. Speakers and Amps but it sounds like Headphones are similar in that they need to be matched to the amplifier driving them.

I have not tried any other headphones besides Grados for comparison. The Grados sounded great but very uncomfortable to wear long term for me.