If you ever get to try out the 598 at a meet in the future, I highly suggest it. Many people who tend to dislike Sennheiser stuff love the 598. I wasn't a fan of the the OLD HD-650, OLD HD-600 or modded HD-555 at all. I read some reviews of the 598 and that it had some forward sounding mids and just had to get it. Loved it immediately. Compared to the modded HD-555 the soundstage is MASSIVE! To me, the HD-598 is nothing like the HD-555 I had. For comparison I'd say the HD-598 soundstage is the 3rd biggest I've heard yet. The AD700 is the largest with the K702 being second. I loved the 598 immediately and it's what made me try the silver screened HD-650 out. I kept comparing it to the HD-600 and ended up with the HD-650 due to it being slightly more revealing and detailed than the HD-600. It took some work to tell the difference in how clear the sound of the HD-650 was compared to the HD-600. I prefer a more neutral headphone, but the HD-650 is close enough on the Micro Amp, but does change the mids a tad maybe. I never once felt the HD-650 was bass heavy. Before I ever tried the HD-650 I always thought it was.
The soundstage of my HD-650 on my Asgard was fairly closed in, but it improved with my E9 (somehow) and on the Micro Amp. I think the Micro Amp makes the HD-650 just the way I like it. The soundstage is quite large. I don't think it's larger than my K601's soundstage, but that's OK. The HD-650's soundstage with the 4 amps I've tried it with is smaller than that of the 598's by far. Not a big deal though. If a $600+ amp could make it larger than that of the 598 I'd be extremely impressed, but I don't think it's possible. I mean how would it be? That's like an amp TOTALLY transforming the HD-650! I do agree that a better amp makes it slightly larger, but I think there HAS to be a limit.
With my HD-650 I prefer CDs from my Oppo, but I guess I should do a 320kbps vs FLAC test again. I personally don't want to do this since I just want to enjoy my music. The HD-598, K601 and HD-650 make me just want to forget all this nit-picking. I think out of the dozens of headphones I've been with I've only come across maybe 2 or 3 that are perfect for ME and my preferences.
I'm not a huge fan of MP3 format, but I don't find 320kbps horrible. Despite using lossless, 320kbps is acceptable if it's absolutely required. I often download albums off Amazon MP3 that's too expensive to buy on CD and even the quality of those 256kbps files doesn't bother me too badly on the HD-650.
If I could tell the difference between 320kbps and FLAC it'd be so minor that It probably wouldn't bother me. I often use an Ipod Touch during weight lifting and ALAC even on a 32gb player really hurts!
I bought some ambient music on Itunes a few months ago that was originally from Japan and the quality is just awful. I don't know who to blame. I buy all my music and often just get used CDs from Amazon. I found a few Cantopop CD originals (that are OOP) on Amazon for under $5. Even if they have minor scratches 95% of the time they're OK.
The problem I really hated with the HD595 was not tonality, but the grain and and also I felt the actual cups and frames (the chassis) was poorly engineered and was not dampening diaphragm excursion adequately and it seems nothing was done about this with the HD598. Its the same problem I have with the K1000s (vibration dampening).
I do feel it is true what they say about the HD650...the soundstage scales well with higher end equipment. Unfortunately for me soundstage takes a back seat to resolution in my preferences and this is where I find the HD650 lacking compared to most of my other cans. I urge for those that enjoy the HD650 to seek out for 70 dollars a pair of Fostex T50 Ortho planar headphone, then one can easily tell where the HD650 is lacking.
I still enjoy my HD650s a lot by the way...but by and large, they have truly been succeeded for me by the LCD2s, something the HD800 could never achieve. I use the HD650 for movies and games where I can't slouch...something that shouldn't be done with the LCD2s weight.
Edited by SP Wild - 5/7/11 at 11:15pm