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.
The DT770 is fine – not basshead, the COP is the same size and configuration as the 770, and both of those, large though they are, are “tighter” built so they feel less clunky than the M50. But the biggest problem for you is that the smaller headphones under $200 almost all have a steeply rolled-off treble, which is trouble for the more refined type of music. One possible exception is the Harman Soho.
Headphones can prevent other people from hearing the sound, either for privacy or to prevent disturbing others, as in listening in a public library. They can also provide a level of sound fidelity greater than loudspeakers of similar cost. Part of their ability to do so comes from the lack of any need to perform room correction treatments with headphones. High-quality headphones can have an extremely flat low-frequency response down to 20 Hz within 3 dB. While a loudspeaker must use a relatively large (often 15" or 18") speaker driver to reproduce low frequencies, headphones can accurately reproduce bass and sub-bass frequencies with speaker drivers only 40-50 millimeters wide (or much smaller, as is the case with in-ear monitor headphones). Headphones' impressive low-frequency performance is possible because they are so much closer to the ear that they only need to move relatively small volumes of air.
I’ve had only a few minutes one day with a 598, so I can’t say exactly. But since the HP100 is closed and the 598 is open, I would get the 598, as long as open back is OK for you. I don’t think you can go wrong with the 598 in any case – it’s a very good headphone. Watch carefully for any cracks to develop though, since there were many reports of that.

Cable dressing and length: Most stereo headphones have just one cable, usually attached to the left earpiece (sometimes called single-sided cabling). Some models -- and all earbuds -- use a Y-cable that connects to both earpieces (double-sided). The actual cable plug, meanwhile, is usually one of two designs: a straight I-plug or an angled L-plug; the latter may be useful if your portable player has a side- or bottom-mounted headphone jack.

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.
Inexpensive: Most casual users can find a good pair of headphones for between $20 and $50. Headphones in this price range sound great, include key features like an in-line microphone, and often support wireless Bluetooth connections. If you’re looking for a reliable set of headphones and you don’t need much more than audio, you don’t need to spend more than $50.
If you won’t compromise on sound quality—and you’re willing to pay for it—the Bang & Olufsen Beoplay E6 may be for you. It doesn’t come cheap, but the Beoplay E6 is one of the best portable wireless models we’ve ever tested. In addition to sound quality, it has design perks including magnets that clip the earpieces together (and automatically turn the headphones off) for easy transport, a braided cable for added durability, and water resistance, according to the manufacturer.
Dale: It’s really the same with any genre or sub-genre of music, that the sound from different artists and tracks can vary a lot, so having more than one headphone is a plus. When only one headphone is available at a particular time (portable use especially), one option is to use a headphone that can accommodate a wide range of genres, in which case there may be compromises to consider. Another option is to carry two headphones – one on the head or around the neck and another in a carry case. Some of the small headphones can make this easy to do.
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.
Over-ear and on-ear headphones effectively block out outside sounds, allowing you to hear your music or whatever else you're listening to crisply and without distraction. Over-ear headphones are sometimes known as full-size headphones because they completely envelop the wearer's ear. This results in what's known as passive noise reduction, which makes these some of the most-preferred headphones available. The only drawback is that your ears and the skin around your ears can get warm and sweaty. These are usually the heaviest type of headphones.