Have been using the HTC 8x for 2 days now. Using B&W P5 headphones.
I did some testing on mostly rock and folk tracks between Beats enabled and disabled. Overall, I'm a little underwhelmed with both. For a while, I was listening with Beats disabled because I thought it had a flatter sound. However, I was getting listening fatigue really quickly.
Today, I decided to listen for a while with Beats enabled. So far, I feel like I'm getting less fatigue. If this is true, then Beats is not just simply about EQ. There would be something going on that is decreasing distortion.
Was curious what was going on here, and found that GSMArena does some amount of technical analysis on phone audio quality:
http://www.gsmarena.com/htc_windows_phone_8x-review-844p6.php
They test phones with all software audio enhancements disabled. I found it interesting that their frequency response curve for the 8X showed a very clear decrease on both the low and high end. Since we know Beats adds back bass and treble, this would seem like the circuitry is being matched to the software in some way to create a balanced sound.
Is it possible that there is something going on here similar to the early days of Dolby NR, where Dolby NR recordings had some frequencies adjusted in the recording, then Dolby would re-adjust them back in playback? The idea being that the original sound quality was better preserved as it passed through a medium that could cause distortion. Back then, it was analogue tapes causing the distortion. Today, it's poor quality files + lots of noise in phone circuitry.
BTW... I do also hear a faint hiss while tracks are playing. That doesn't seem to depend on Beats on or off.
Ed