mobile

I bought my Z3(D6653) less than a month. After using a few week. The speaker sound has become softer and not loud as before (very obvious, tested in sony store). I use to listen to music when I bath. I believe the speaker is in dry state and isn't defective due to both top and bottom speaker produce low sound even in the max volume. I did try using PC Companion to repair my phone to stock, but the problem is still there. Before that, I flash speaker mod for stereo sound for incoming call with backup, after restore and flashing new ftf the problem still there. I would like to ask did anyone here experience the same issue?