Build quality should be the same. They are made by the same company and likely have the same drivers. I would think the 950 would have better sub bass. The 950 should be more comfortable.

They look like a Superlux hd662 which is a very good budget studio can. I have one and really like it. The fabric ear pads should make them that much better.  

I believe the reason for no response is that it is not a good comparison to put it mildly. My hd662 Superlux destroy the panasonic in every way but it is not in the same league as the Beyer. You get what you pay for with the Panasonic. Fragile and really don't sound that good after the initial...

At least you can change a room and move speakers around to find the sweet spot. Not so much the shape, size and neural response of the ear which is the "room" for headphones.

Quote: Did you get these?   http://www.ebay.com/itm/Velour-Cushion-For-Superlux-hd662-Series-hd662b-hd662f-hd-662-b-662f-Headphones-/261184879479?pt=US_Replacement_Parts_Tools&hash=item3ccfd4fb77

Quote: Yes. Single driver speakers in a really crappy room causing  many phase cancellations and resonances.

If you search a bit you will find lots of information. That being said I have never found a post where someone owned and compared all three variants. I know the B model has more midbass and the F model has less bass than the other two and is brighter at the top. I have the CAD mh310 which is a...

Yes.   It seems that all headphones have inherent peaky treble response, some of which is by design. Check the graphs. There is almost always a big dip between 3k and 5k accompanied by a few more dips and peaks and then a sharp rise in the 9k 10k region. I do my best to obtain a flat...

If you are willing to spend 60 forget the pans unless you want to replace them in a few months. They break and really don't sound that good.

Quote:   Well said. The next best thing after pads is eq to tame the highs.

I noticed that Koss sells replacement ear pads for cheap on their website and the UR20 seems similar in size.

Let me play Letterman.   She might grow to like them. IN HER PANTS!

The Behringers stuff is a great value but they usually compromise the signal path at some point with lower quality dacs or op-amps. It is not audiophile equipment. You might want to consider one of the EMU products which incorporate high quality components and include dsp effects. You can stack...

I think the increased driver distance from the ear changes the sound more than the material used but both must have some effect. My observation is that the upper mid's and highs diminish with distance from the ear.

I chose seeking something else. I would have chosen flat but I use EQ to get as flat as I can since we all know there is no perfectly flat headphone.