After 48 hours of burn-in, the new
M760 sounds as quiet as the "bad" one, but SQ is almost on par with the "good" one.
I think it's because of the volume control circuit on the wire - really bad idea for an audiophile-targeted product.
Check the "MX660 and MX760" section at the link below to see how it can affect the SQ:
http://www.head-fi.org/t/430222/review-a-novices-take-on-sennheisers-mx360-mx460-mx660-and-mx760
I'm supposed to get the original Sennheiser MX760 next week, will be interesting to see if it's anywhere near as good.
The
M1 sounds just as good as M760, but has a different sound signature.
The mids and bass are leaner, soundstage is bigger. They are very airy, which can sometime make the song sound artificial.
Sometime female vocals can sound a bit lispy (rare).
It's less euphonic and more analytical.
The best part about M1 - both M1s sound great, no quality control issues here.
To compare with M760, where I got one "good" one, one "almost as good" one, one "bad" one and one dead one - this is a much safer choice.
At 15$, it's your best bet for top sound.
M3 isn't really worth talking about. It's better than your typical earbud, but isn't as good as M760/M1 or the Blox lineup.
It's way too warm. Vocals sound usually OK, but instruments are way off.
At 13$, it's just 2$ cheaper than M1 - the choice is clear.
I am starting the burn-in of PK IE8 and AP8.