Due to the extremely thin and light diaphragm membrane, often only a few micrometers thick, and the complete absence of moving metalwork, the frequency response of electrostatic headphones usually extends well above the audible limit of approximately 20 kHz. The high frequency response means that the low midband distortion level is maintained to the top of the audible frequency band, which is generally not the case with moving coil drivers. Also, the frequency response peakiness regularly seen in the high frequency region with moving coil drivers is absent. Well-designed electrostatic headphones can produce significantly better sound quality than other types.[citation needed]
I have heard only the 8.35D, which are slightly dark (tilted toward the low end a little bit). But the 8.35D is very smooth and linear overall, excellent for many genres if not all. With the SRH840 you should expect a big hump in the upper bass – not ideal for monitoring. The KRK 8400 seems like the most accurate of all which is ideal for monitoring, but that’s based on a bunch of reviews, and not all of them agree 100 percent.
Sealed models are ideal for private listening, where you don't want the sound to be heard by other people. Open headphones -- such as foam earpad models and many sports designs -- are acoustically transparent and allow outside sound to be heard by the headphone wearer, and a good deal of the headphones' sound will be audible to anyone near the listener.
I see, yes, but that should serve as an important lesson – the soundstage is not real in the same sense as actual tones, bass, treble, whatever. Soundstage is a perception that’s based on many factors, and here’s a challenge for you: You should be able to find some music tracks that have better soundstage on one headphone, and other tracks that will be better on the other headphone. Most of the time it will be just one way, but when a closed headphone beats an open headphone, I expect the open headphone will still show an advantage on some tracks. Your hearing perception could be tricked by simple things like a recess or emphasis in certain frequency ranges, or even phase shift when more than one driver is in the cup.

Choosing the right headphones makes it possible for you to hear your music the way the artist who made it intended, with all the nuances from the right bass and treble levels so you can hear every drum beat and guitar strum. Not all headphones are ideal for everybody and are a matter of personal taste, comfort and style. Find the ideal pair of headphones to use with your mobile device, stereo or computer, available at our Every Day Low Prices, and get your groove on.