Over the Ear Headphones that have a sweet sound.

Define "sweet sound" - do you mean "sweet" in terms of "syrupy, romantic, and warm" or in terms of "dude, sweet" ?

If the former, the ESW9 would be be a pick.

So yes, the "syrupy, warm, romantic" kind of sweet - where it doesn't burn your earholes. I'd look at the ESW9 (be sure to look at an authorized dealer; they're very commonly faked). They're a bit on the boomy side, but they're very smooth sounding (the top-end is rolled off imho; they're dark and relaxed). If you're fine with a substantially larger around-ear set, the Kenwood K1000 is a very solid upgrade from the ESW9.

The Denons are a bit harder to categorize. The 1xxx models are a different beast than the 2000/5000 and the 7000 is reportedly apart from that (I have not tried the 7000). IMHO the 2000/5000 are more aggressive and "punchy" than the Kenwood, and (especially the 2000) can border on harsh with some material. The 1000/1001 wasn't as impressive, but I don't remember them as boomy. The 1100 is supposed to be very boomy based on a few reviews. I think the A100 fits in as an improved 1100 (it's more related to that lineage than the 2000/5000/7000 at least).

If you can do open-back, have a bigger budget, and do not care about portability, the Koss ESP/950 will certainly fit the bill of no sibilance/no harshness/no boominess while being relaxing and overall excellent (they're a very dramatic departure from anything else mentioned, but they also meet the requirements you laid out). They're quasi-portable (if you feel like lugging around the entire camera bag they come with, and they again offer no isolation - I have no idea what the battery life is like either), but I wouldn't really regard them as suitable for going on an airline or even a morning commute. Keep the IEMs for that.

I know, kind of a smattering, but you have a fairly open set of requirements, and I'm assuming a reasonable budget based on the price of the Miles Davis.
Edited by obobskivich - 6/10/12 at 12:48pm

No idea on the Denon models - you will have to wait until they come out in order to get a better gauge on them (you could always be one of the first to have them and write about them ). Within your ~$400 range, the Kenwood KH-K1000 or Denon AH-D2000 are probably the best bets. I'd take the Kenwood (and it does tap out your entire budget).

The ESW9 aren't harsh imho - I'm not sure where that's coming from. They're on the dark side, and fairly "romantic" sounding (the mids are colored and very sweet/syrupy; almost to a fault). The only complaints I would levy against them are on the bass (it all depends on how much you define as too much), and potentially on comfort. They have fairly soft leather pads, and are very light, but may cause comfort issues if you just really dislike on-the-ear headphones. I found them manageable albeit a bit awkward. The Kenwood or Denon are much less of a concern when it comes to comfort, due to their bigger pads and around-ear fit. The Kenwood are a bit heavy though (at 390g - they weigh roughly as much as the Beats Pro, but are larger, so the weight distributes much better).

Ah, I couldn't imagine the ESW9 with my sunglasses - let alone normal glasses. So I would pass as well. Look at the Kenwoods; the pads are very squishy and large, they're very comfortable. Otherwise wait for the Denons.