I am a researcher in human factors psychology, as well as a big fan of headphones and good sound in general. My question is this: What headphones would you recommend for scientific research? Specifically, I am making binaural recordings from inside a moving vehicle and playing them back to research subjects via headphones in a lab. What I’m looking for is something with a flat frequency response (especially from 20-1000 Hz), quick response, and good spatial imaging. The headphones would also have to handle the high SPL of deep bass frequencies present in vehicles. The Sony MDR-7506 we currently have in our lab simply can’t handle this bass with any degree of accuracy. My own Hifiman HE 400 handles the bass well, but I would consider these phones to be too colored. Tyll at innerfidelity recommended the Sennheiser HD 800 for scientific research, but that is beyond our budget. Let’s say that our budget is up to $850 (i.e., HD 700), but cheaper is better. Any recommendations?
To save you the trouble of pointing out caveats, I know that nothing will be perfect, there is no such thing as a totally flat frequency response, amping requirements will differ, accuracy doesn't necessarily sound "pleasant," etc.