I read a lot of reviews about bad sound on the Nokia Lumia phones but I tried various hifi headphones on it and it was amazing. The issue moain Is That You can not equalize the sound to match your headset. I wanted a headset with controls and microphone That Could match my hifi headphones, and I Decided to Try these. The packaging is amazing and the design matches the Lumia 800 (black) and everything feels high quality. There are many shapes of earpads for them to match your ears. I first tried the ones indeed are already on them, and I found the bass too high. Then I changed the pads and got too little bass. Then I tried some pads in between and the sound is perfect :) So even if you cant change the bass on the phone itself, you now can by changing the pads on the headset.
The controls work As They Should, therefore When the screen is off.