Asterisk 13 + USB M-Audio Mobile Pre 2nd mic don't work

Hello everybody!

I use a cloud server running Ubuntu 14 + Asterisk 13 to make links from our reporters on field with our radio studio.
Well, it work’s fine running Opus codec on 48kbps, so last week we find an issue: when we try to use a M-Audio Mobile Pre (2 mic ports) only the 1st one works on Asterisk. We use the Phoner Lite software under windows but we tryed a lot of other software choices, even with the same result, only the mic 1 “insert” audio to asterisk.
On windows recording devices configuration both mics works fine, as weel on other softwares, but on asterisk only the mic 1 works.
I’ve tried to find some answer about it or some explanation but without success.

I don’t think this is an Asterisk problem, Asterisk only receives the audio you send it from you soft phone.

Maybe you can find some software that’ll mix the audio from the two mics together and then you can send that audio into your soft phone.

Hi John:

I guess the same but the audio from 2 microphones connected on M-Audio USB interface is already mixed. As I show on print screen attached on my post the signal of 2 mics is show on windows as only one signal (mixed) of these 2 mics.

My question is if asterisk have some characteristic tha allow only one mic or if it’s a softphone/usb interface issue.

thanks for your reply!

Nope, Not an asterisk side issue.

Asterisk doesn’t know where the audio comes from, It’s just receiving a UDP stream from your computer.

Thanks, John!

I will search more on the softphone.