m17/ghost/xt1052 strange audio problem

[materialdefender2306]

Hi,

after having received a used Moto X I made the mistake of immediately rooting it and flashing a custom ROM. After that, everything worked fine - except for phone calls, where you can hear an echo of your own voice (both with speakerphone off or on) but the other person can't hear anything at all. I thought the problem was with the ROM and restored the stock ROM, but no luck. My last-ditch attempt at solving the problem was to re-flash what seemed like the proper modem firmware (I think it was for the XT1052, but not 100% sure). Anyways, no dice either.

Didn't try to use the phone again until today, and noticed something funny:

• When I blow into the front microphone, that blowing sound can be heard loud and clear by the other person.
• Investigating further it turns out: in an app like RecForge, where you can choose either microphone, the back microphone works just fine. Good, loud, clear signal. And the front microphone shows the same symptom as in the phone app; only blowing into the front mic produces a strong signal. VERY loud shouting produces a very weak, but noticeable signal - of course that might be because very loud shouting moves a lot of air.
• Trying to google this issue gets you lot of hits by people suffering from it on a variety of devices, interestingly many of them Motorola phones. Unfortunately, none of the suggested solutions work for me. What struck me though is that for one guy, covering the back microphone with two layers of tape seems to work. That got me thinking: blowing into a microphone basically produces white noise; the kind of noise you'd be looking to remove with active noise cancellation. Not sure how the echo effect of hearing yourself speak figures into that (except that it proves the microphone is not broken on the hardware level).
• Using a BlueTooth headset everything works just fine.

One theory I have is that the microphones might be misidentified/swapped (i.e. front for back and back for front) in the firmware or software. Is there any way to mess with this (swap microphones, disable second microphone, disable ANC, etc.)? Preferrably without compiling one's own ROM, but if anybody could give me pointers towards how to compile e.g. LineageOS under Linux, I'd be happy to give it a try, given how nice a phone the Moto X is.

 

[gowtham3834]

Hi,

after having received a used Moto X I made the mistake of immediately rooting it and flashing a custom ROM. After that, everything worked fine - except for phone calls, where you can hear an echo of your own voice (both with speakerphone off or on) but the other person can't hear anything at all. I thought the problem was with the ROM and restored the stock ROM, but no luck. My last-ditch attempt at solving the problem was to re-flash what seemed like the proper modem firmware (I think it was for the XT1052, but not 100% sure). Anyways, no dice either.

Didn't try to use the phone again until today, and noticed something funny:

• When I blow into the front microphone, that blowing sound can be heard loud and clear by the other person.
• Investigating further it turns out: in an app like RecForge, where you can choose either microphone, the back microphone works just fine. Good, loud, clear signal. And the front microphone shows the same symptom as in the phone app; only blowing into the front mic produces a strong signal. VERY loud shouting produces a very weak, but noticeable signal - of course that might be because very loud shouting moves a lot of air.
• Trying to google this issue gets you lot of hits by people suffering from it on a variety of devices, interestingly many of them Motorola phones. Unfortunately, none of the suggested solutions work for me. What struck me though is that for one guy, covering the back microphone with two layers of tape seems to work. That got me thinking: blowing into a microphone basically produces white noise; the kind of noise you'd be looking to remove with active noise cancellation. Not sure how the echo effect of hearing yourself speak figures into that (except that it proves the microphone is not broken on the hardware level).
• Using a BlueTooth headset everything works just fine.

One theory I have is that the microphones might be misidentified/swapped (i.e. front for back and back for front) in the firmware or software. Is there any way to mess with this (swap microphones, disable second microphone, disable ANC, etc.)? Preferrably without compiling one's own ROM, but if anybody could give me pointers towards how to compile e.g. LineageOS under Linux, I'd be happy to give it a try, given how nice a phone the Moto X is.

i understand your problem may be a problem with the rom flashed at first using fastboot. do a thing back to stock 100% using the steps given here may it helps you.
it helped me to sort out my other networs issues problems.

 

[materialdefender2306]

gowtham3834, thank you for the answer. The ROM I currently have on the phone was installed through the method you mention, and I used XT1052_GHOST_RETDE_5.1_LPAS23.12-15.5-1_cid7_CFC.xml.zip. I'm not convinced that it's a ROM issue, but I'll try out some of the other ROMs at firmware.center and see if any of them behaves differently.

 

[materialdefender2306]

So I tried out all of the RETDE firmwares now, no luck. Even tried a French one by accident, after which I was offered an OTA update, but that didn't help either. For no good reason other than it being very new (Feb 5, 2017) I then installed XT1052_GHOST_RETEU_5.1_LPAS23.12-15.5-1_cid7_CFC.xml.zip. Still the same problem: front mic and back mic are basically swapped in the eyes of the OS.

Here's how I did the flashing:

#!/bin/bash

mfastboot="sudo ./linux-fastboot"

$mfastboot getvar max-download-size
$mfastboot oem fb_mode_set
$mfastboot flash partition $1/gpt.bin
$mfastboot flash motoboot $1/motoboot.img
$mfastboot flash logo $1/logo.bin
$mfastboot flash boot $1/boot.img
$mfastboot flash recovery $1/recovery.img
$mfastboot flash system $1/system.img
$mfastboot flash modem $1/NON-HLOS.bin
$mfastboot erase modemst1
$mfastboot erase modemst2
$mfastboot flash fsg $1/fsg.mbn
$mfastboot erase cache
$mfastboot erase userdata
$mfastboot erase customize
$mfastboot erase clogo
$mfastboot oem fb_mode_clear

Any takers??