I am willing to spend up to $1,000 for:
- Over the ear, closed back (minimal leakage)
- Good detail in the mids, not overwhelming bass
- Comfortable for long listening
- Detachable cord a plus, cord only on one side a plus
- Not requiring a headphone amp a plus, but if the total of headphone + amp hits 1k, that could be OK
I agree with Max with the LCD-2's. While they aren't closed headphones, they have an amazingly linear frequency response. That being said though, I just spent about ~$100 on Fostex T50-RP's and modding material and I have a headphone that competes with the LCD-2's. It's a cheap, planar magnetic headphone with amazing mids and bass extension. AND they are close backed. Now, I should also mention that I've never tried the LCD-2's myself, but I followed an in depth tutorial on how to make my Fostex sound just like them (according to many head-fiers). Personally, if I had that budget, I would put most of it towards an amp/DAC. Or buy 5+ different headphones and sell the ones you don't want :P
The T50-RP is semi-open.