It took me a while to figure out how to keep them on my head. You have to pull the cable over your head in a vertical position and it fits perfectly. Sounds quality is great. I agree with traccie 'Can hardly feel that you wearing them'.
 

I thought it was only me who couldn't get these to stay on my head?!! Wanted fuss free headphones that would sit in my ears and not fall off but however much I twist and turn them I can't work out how to keep them on my head! Maybe Tobias and I just have oddly shaped heads?!
 

Bought these earphones today, and I am very pleased with them. I was going to get the MX 90's, but my budget didn't quite stretch that far, but I am glad with my choice. It took me a while to figure out how to actually put them on, but after using them for a day it becomes almost natural. I could see the design being off putting to some people, but I feel it is a huge advancement over the traditional earphone design. The sound quality seems to be very good, but I have as of yet to test them with some high quality ripped music, and have so far only been used with my Samsung YP-Z5 upto a quality of about 192 kb/s, but this is mostly what I'll be using them for. The manufacturer quotes the LX 90's frequency response as 19-22,000 Hz, the impedance as 64 ohms and the sound pressure level as 116dB (1kHz/1V rms). Overall, the LX 90's are excellent earphones, easily the best I personally have ever used, and definately the most comfortable, somtimes I forget I have them in, and they don't have to be pushed into the ear to get them to stay put as the headband type cable connecting the two earpieces keeps them in place. I definitely recommend these to anyone willing to trying something new and looking for some decent earphones.
 

The sound quality was good but I had a problem with them staying on my head, although friends have them and don't appear to have the same issue. Maybe it's just me..