has anyone changed the call volume and could give me recomended numbers
I totally agree with Agoattamer that you should stick with Samsung's settings however for me the volume is still not loud enough when driving so I raised it just a tad.
If you choose to raise yours you recognize that you may be running the risk of lowering your speakers lifespan.
(for me this tweak left 1-5 alone but 6 and 7 feels one notch higher)
If interested
Dial First
*#197328640#
Menu Settings
8-1-3-1
Samsung Impression Call Volume Increased Settings
Original Value Changed Value
0. [2] rx: -8.0dB 0. [2] -8.0 db
1. [4] rx: -5.0dB 1. [4] -5.0 db
2. [6] rx: -2.0dB 2. [6] -2.0 db
3. [8] rx: 1.0dB 3. [8] 1.0 db
4. [10] rx: 4.0dB 4. [10] 4.0 db
5. [12] rx: 7.0dB 5. [12] 9.0 db
6. [14] rx: 10.0dB 6. [14] 12.0db
Note so far only the values were changes in 5 & 6
(obvious credit on how to mod values goes to Agoattamer but use at your own risk!)