Open up audiopara4.csv from /system/etc . You will need excel.
Scroll to row 75 and look in column H. From there down is where you would set the rx volume. As for what it needs to actually be set to... test and find out.
But I agree the phone is plenty loud for me.
Here's a little help to get you started:
Copied from row 75 column H down to row 80. Row H is in hex so I converted it to decimal form for you to show you how they get progressively larger (louder). So you'll need to convert some decimal numbers back to hex and then replace them. Maybe start with 40000 in vol 5 and see how that goes. As for why vol 0, 1, and 2 are the same? I couldn't tell you. Trial and error my friends! If there is enough demand for this I could figure it out and put it in to fresh rom but I've got 10 other projects going on right now so people would have to want it. heh.
Code:
PHONE_HEADSET_VOL0 390a (14602)
PHONE_HEADSET_VOL1 390a (14602)
PHONE_HEADSET_VOL2 390a (14602)
PHONE_HEADSET_VOL3 47CF (18383)
PHONE_HEADSET_VOL4 656E (28526)
PHONE_HEADSET_VOL5 8F47 (36679)
*I'm not responsible for you blowing out your speaker.
