I originally ranked my headphones like this, with cost, amp needs, etc, not being a factor. They were ranked PURELY on SQ alone:
1. Sennheiser HD650
2. Sennheiser Momentum
3, Sennheiser PX360
4. Sennheiser HD429*
5. Bose On Ear
6. Bose In Ear
*The HD429 were previously unranked, as I just BARELY got em last week. I ranked em after a proper break in and some good long listening sessions.
Another ranking would involve PRICE. What I consider "price" is not just the cost of the can, but the cost of the equipment needed to actually get something descent out of your headphones. So with that idea, with price involved, here's how I rank em:
1. Sennheiser HD650 - If you can get them for the price I got the for ($367 total, including shipping), then these rightfully belong at #1 even if price is considered. To really get these to sing you need at the very least a descent source and a descent desktop amp. By descent, I mean a mid-fi CD/SACD/DVDA audio player, a good soundcard for your computer, or a mid-fi DAC. As far as descent desktop amp, a FiiO E9 has more than enough power to drive them. For a while I mainly hearing them through the FiiO E7 DAC docked to the E9, and although they sounded great, I always felt they weren't really being used right. I truly fell in love with my HD650s after hearing them through my Yamaha DVD-S2500 player and E9 amp. But the HD650s do get better and better as your equipment gets better, the HD650s will rarely be the bottleneck in your system. Right now, they are used on either my computer through an Emu 1212m card to a Yamaha 5950 amp, and out to the E9, and they sound awesome. But when I plug them in directly into my Oppo BDP-105 and play SACDs or CDs, wow....I mean WOW. The Oppo not only has high end DACs, but also a high quality, head phone amp built in, and plugging the HD650s into this player was a major leap in SQ over any other set up I've plugged them into. True to the word: HD650s scale up scary good!
2. Sennheiser HD429 - Of all my Sennheisers, these are weakest overall cans by SQ (as evidenced by the 'price is no object' ranking. However, they require nothing else but a descent source. I hooked them up to my J3 and they sound great unamped. If you do have some amps or some nicer stuff, these will scale up well enough. Hearing them through the Emu 1212m to 5950 to E9, I rocked for 3 hours long, without thinking of switching up headphones; but again, they deserve the #2 spot because the dont REQUIRE better equipment, and still sound great. You spend $50 on these and that's all you will need to spend on; you get great sounding cans, period.
3. Sennheiser PX360 - I got these headphones from about $120 over a year ago, and they really do sound great. However, you get almost NO volume from a J3 if you dont get at the very least a portable headphone amp. I use a FiiO E7 with these, but a cheaper E11 will probably work fine (from what I understand, is that the E11 might be the better amp, but the E7 cost more because it is also a DAC). Once amped, these sound really good, and while they don'r reach the level of the Momentums or HD650s, they are still a worthwhile headphone.
4. Sennheiser Momentum - You WILL pay $350 for these new (at least the black ones). Although they sound good off a DAP unamped, they do not sound like $350 cans without an amp. Again, once you get an amp like an E7, you will be set. I usually listen to these through and E7 and Cowon J3 and they are CLEARLY better headphones than the PX360s, however, they also cost at least $200 more, and they are NOT $200 better sounding. I wrote up a review comparing the PX360s to the Momentums and said they were worth the upgrade, however thats taking into consideration the "law of diminishing returns": the idea that to move up in quality in audio gear, you have to pay more than what you get in return, in other words, if you want something twice as good, you will be paying much more than twice as much for it. But this list is not about that, its about pure SQ vs Price, so with the "law" thrown out the window, the Momentums rank lower than the PX360s. Dont get it twisted though, I bought the Momentums as an upgrade to the PX360s and I don't plan on returning them, they are here to stay!
5. and 6. Bose cans. The good thing is that these will play very loud with no amplification at all, however, now that I've been exposed to more natural sounding headphones, the super piercing, unnatural highs of the Bose headphones kill their value as $80-$100 headphones. The HD429s are better headphones, regardless of price, but considering that they cost $30-$50 LESS than the Bose, it really knocks the value of the Bose cans severely.