Just had a quick listen for about 10 minutes this little thing sounds pretty good i didn't notice any bass reduction at all, i listed to the same songs on my ZX300 it had the same bass impact .
I noticed the sound is tuned differently from the A105 if i recall.... its slightly brighter on the A306 the A105 was warmer but it sounds damn good
To my ears my unit sounds fine i definitely have plenty of bass from the tracks i have played so far, the sound from the 3.5mm is really surprising it beats the ZX300 3.5mm there is more details must be that added brightness of the sound, it is not a harsh brightness but done to get a little more space from the music . Sony have a little hit on their hands with this one
I will do the REW test later as i am charging it at the moment .....