[Doctor Mesmer]

I've owned the above cans from new and love the clear, detailed sound; however, they're definitely quite trebly and lacking in bass (and this was true from the day I got them). I've had other Sennheiser cans over the years, including HD480 and even a set of PX100 for use with my iPhone. I like the PX100s, but they're probably too bass-heavy, so I can reassure you that I'm not a serious basshead.
 
If anything, I like a detailed mid and top end, which the 565s provide, but they can feel quite harsh on the ears after an extended listen. The issue is mitigated when I listen through my warm-sounding Arcam Alpha 7SE CD player and Alpha 8R amp; however, modern compressed pop in MP3 format through an iPhone really exaggerates the issue (solution: use my PX100s - I'd also look quite a sight walking down the street wearing 565s!).
 
My question is this: I can't believe a headphone of this standard could be harsh-sounding and lacking in bass; consequently, might there be a problem with them? Is there a separate bass driver which might have a poor connection, for example? If so, is this something I could ascertain myself? Or, alternatively, are they known for being light on bass?
 
Lastly, the right connector on these cans very occasionally needs unplugged and plugged back in again due to what seems like a poor connection. This has happened since day one (I know, I should have returned them...). Could this be a related issue?
 
Don't get me wrong: these cans absolutely trounce anything else I own and the connector issue happens very rarely, but any advice/comments (especially from other 565 Ovation owners) would be welcome.
 
 

 

[Digital-Pride]

Hmm, it seems to me that the HD650 would be a natural progression for you, as they have a weightier low end as well as a more laid back overall presentation.

 

[pp312]

Ditto--the 650 is the next natural step. However, I owned the 565 and don't remember them being bass light and trebley, not to mention harsh (never harsh!). The connection issue is well known but shouldn't affect sound quality--and no, there's no separate bass driver. Hard to explain--but of course if you can afford to move on to the 650 you won't need to.