mic distortion / noise cancellation

[drake484]

Issue type

User interface

Device

Device (evergo)

crDroid version

crDroid 11

Exact version / Build date

Bug description

That bee / high frequency beep noise the other person hears is mic distortion / noise cancellation loop. Your mic gain is too high or dual-mic noise cancellation is broken in that build.

For Evergo / EverGo devices on crDroid 12, this happens because:
Why it happens

1. Dual mic / Noise cancellation bug: crDroid uses generic audio_platform_info and mixer_paths. If fluence / dual mic is enabled but your device only has proper tuning for stock, it creates feedback that sounds like a bee buzz to the receiver.

2. Mic gain too high in mixer_paths.xml: In many 12.11 builds, DEC and ADC volumes are set to 95-100. That clips and creates high frequency hiss.

3. VoLTE / VoWiFi HD codec: If you call on VoLTE, crDroid sometimes forces EVS / AMR-WB 23.85k. The device's acdb doesn't support it properly and adds background beep.

4. Google Dialer + built-in call screening: crDroid's Dialer noise suppression conflicts with hardware NS.

Steps to reproduce

Call some buddy

Relevant log (logcat/build log)

No log

Screenshots or videos

No response

Solution

On crDroid 12.11 this is a very common call bug - it's almost always software audio config, not hardware.

That bee / high frequency beep noise the other person hears is mic distortion / noise cancellation loop. Your mic gain is too high or dual-mic noise cancellation is broken in that build.

For Evergo / EverGo devices on crDroid 12, this happens because:
Why it happens

1. Dual mic / Noise cancellation bug: crDroid uses generic audio_platform_info and mixer_paths. If fluence / dual mic is enabled but your device only has proper tuning for stock, it creates feedback that sounds like a bee buzz to the receiver.

2. Mic gain too high in mixer_paths.xml: In many 12.11 builds, DEC and ADC volumes are set to 95-100. That clips and creates high frequency hiss.

3. VoLTE / VoWiFi HD codec: If you call on VoLTE, crDroid sometimes forces EVS / AMR-WB 23.85k. The device's acdb doesn't support it properly and adds background beep.

4. Google Dialer + built-in call screening: crDroid's Dialer noise suppression conflicts with hardware NS.
   Fix it step by step
   Try in this order, test a call after each:

5. Quick fix in settings:
   • Settings > Sound > Turn OFF Adaptive Sound if present • Phone app > Settings > Calling accounts > Turn OFF WiFi Calling • Try turning OFF VoLTE once to test: Settings > Network & Internet > SIM > Disable VoLTE. If noise goes away, it's a VoLTE codec issue.

6. Fix mic gain (this fixes 90% cases):
   You need root file manager.

Go to /vendor/etc/mixer_paths.xml or /vendor/etc/mixer_paths_*.xml

Find:

Change to 80-84.

Find:

If it's above 8, set it to 6.

Reboot.

3. Disable fluence (dual mic noise cancellation):
   In /vendor/build.prop or /system/build.prop add / edit

persist.audio.fluence.voicecall=false
persist.audio.fluence.voicerec=false
persist.audio.fluence.speaker=false
ro.qc.sdk.audio.fluencetype=none

Reboot.

4. In crDroid settings:
   Settings > crDroid Settings > Misc > Disable In-call audio enhancement if you have it.

Also in Developer Options > Disable Bluetooth A2DP hardware offload - sometimes it interferes.

5. If still there:
   Flash different firmware / modem. On many Evergo devices you MUST be on latest stock firmware base before flashing crDroid 12.11. Flash stock OOS / MIUI firmware for your region, then re-flash crDroid WITHOUT wiping vendor firmware.

And in Telegram group for your device + crDroid 12.11, ask for call fix zip - most maintainers have a flashable acdb fix for this exact buzz.

Additional context

No response

Acknowledgements

• I've checked device is officially supported and that no support is provided for unofficial devices (for device specific reports and not source related).
• I'm running latest version available on crdroid.net for this device and that the device is still maintainer supported (not flagged unsupported on download page)
• I have searched the existing issues and this is a new and no duplicate or related to another open issue.
• I have written a short but informative title.
• I filled out all of the requested information in this issue properly and understand that not doing so will automatically result in closing of ticket.