I've a HTC One X, Endeavoru and the problem is too low in-call volume. I tried Vol+ during the call but no effect, it is to low for me. I don't know maybe the speaker is broken, but I bought the phone brand new.
Is there any application or kernel witch can increase in-call volume?
I already have:
CM 11 NIGHTLY ROM
On the stock ROM(and 4.1.1, 4.2.2) I had the same problem.
PS. I did not use a toothbrush because my phone is new and speaker grill is not a problem.