Read this from a current thread just a couple threads down from this one.
I have Audeze LCD-2's, HiFiMan HE-6's, and Denon AH-D7000's, as well as Koss ESP-950s, Stax SR-007 Mk1 and Stax Lambda Signature, along with a number of amps, DACs and so on.
The LCD-2's have the bass I like best- perfect texture and "slam" as well as extended, flat response. The LCD-2's also have very good mids and treble that is recessed. Above the midrange, the LCD-2's are not masters of detail.
The HE-6's offer more treble detail, and fine bass, but are not the equal of the LCD-2's in bass definition.
The AH-D7000's have the most bass, that's all I can say about them.
The SR-007's offer the most neutral sound of any headphone I've heard. Nothing is emphasized; detail is present only when there is detail in the signal. With bass-centric tracks, these 'phones don't deliver the bass perfection of the Audeze, but the bass is not lacking. Their mids and treble are beyond reproach.
The Lambda Signatures are famous for an upper midrange / low treble 'etch' which IS quite noticeable, but I like listening to them anyway because they offer a lot of detail (sometimes they have a little TOO MUCH emphasis on detail, this is the nature of the 'etch.') Bass is extended and clean, but not as satisfying as the LCD-2's.
The Koss ESP-950's have a quite different 'voice' from the Stax, but you can tell from their smoothness and top-to-bottom detail that they are an electrostatic high-end phone. They have more bass 'slam' than any other electrostatic, but they do not have the 'taut depth' of the LCD-2's. Compared to the Stax, the Koss tend to be a little warmer and have a bit more midrange 'presence,' but the detail in the mids and treble are definitely electrostatic in character- that is to say, there's an addictive transparency to all electrostatic headphones that I have not heard in any dynamic or planar headphone- ( the Sennheiser HD800 comes closest, but doesn't quite achieve a cigar.)
If I had to choose ONE of these headphones, it would be the Koss ESP-950. With it's better 'slam' and warmth, it is a little closer to an "all round' headphone than the Stax, and it offers a transparency that the dynamic and planar headphones just can't match.
If I was an absolute basshead and the number one most important thing I wanted was bass quality/punch/depth, then I'd have to go with the LCD-2. However, as much as I like the effortless extension and mastery of bass texture offered by the Audeze, I find I can live with the bass from the Koss- which is "only" excellent compared to the "without peer" bass of the LCD-2; in addition to bass that is extended and tuneful, if not quite the equal of the LCD-2, the Koss offers greater mid and treble transparency than the LCD-2. I'm addicted to that transparency.