3.5mm Audio Volume

Other Hardware General Electronics
1

I'm having some issues with wiring a TRRS 3.5mm audio jack. This is my current config excluding dotted line and resistors

This gives me decent microphone but also speaker functionality with low volume. Depending on how I change up the wires I can get decent speaker volume with no mic or sometimes use the speaker as a microphone at the same time. I'm wondering I can boost the volume by combing the two speaker rings and using the resistors. If not is there another way?

2

You need to tell us what this is for.

3

The jack connects to a GSM board. I get good volume from another cellphone speaking into a microphone. Speaking into the phone however gives me low volume from the speaker connected to the jack which is connected to the gsm board.

However this changes like I say in the OP depending on how the wires are switched around.

4

What about consulting the schematic of the GSM board, and the datasheet for the GSM module?

// Per.

5

Zapro:
What about consulting the schematic of the GSM board, and the datasheet for the GSM module?

// Per.

I've looked over the datasheet here but I don't really get anything out of it that helps.

2048×1358 350 KB

The plan to combine the two speaker channels didn't work. Interestingly though if I left in one with the resistor the speaker audio is back to normal but the mic is again nonfunctional.

6

This is taken from the SIM900 Hardware manual:


You can get the complete manual here:

// Per.

7

Zapro:
This is taken from the SIM900 Hardware manual:

Dropbox - Error - Simplify your life
Dropbox - Error - Simplify your life

You can get the complete manual here:
Dropbox - Error - Simplify your life

// Per.

Thanks! Definite improvement. Not quite as much as I'd like but still a big step in the right direction.