[quote name='Rich44' post='1092999' date='Jan 17 2011, 07:47 PM']In terms of sound, can someone explain what frequency responses are about?[/quote]
Not really, I assume it's the same as speakers whereby the less db loss you get on low frequencies the better.
Sounds like you need a pair of closed back 'phones. Have a look at Sennheiser HD201 or 202. Both are in your budget and look pretty good.