I got through several sets of "consumer" headphones before going for studio jobs. In my case AKG K240. These are 55ohm and as noted above do take a bit of extra power to make them move and do have a flat response, as they should for recording. Some practice amp headphone outputs are dual purpose line output which is not enough to drive the cans and I end up with the amp cranked to 11 and which just sounds bad. So I put the line signal through a PV Microbass which I use as a headphone amp. I could use a line-input to a hi-fi amp etc as a headphone amp. The PV just happens to be available, portable, mono and bullet-proof, and has a proper headphone level output. Tip - if you are going to play at 2am with the cans on then do make sure the speakers are actually shut off before rocking out at maximum!