Help with microphone audio noise - Hardware Hacking General

Hi all,
I'm writing here in the hope of getting some better understanding of how microphones works, and maybe some hints on how to fix the problem I'm currently banging my head on.
I'm porting the Xiami Redmi Note 7 Pro to Ubuntu Touch, and I'm facing an issue with the audio recorder from the microphone: the top microphone works perfectly, whereas the lower one (the one used for phone calls) records a lot of background noise, in addition to the voice. I've spend several days trying to debug the issue, trying different stuff both with the kernel and with the mixer_paths.xml configuration, but every time when I thought I fixed the problem, after some reboots the issue was back.
I believe that the noise that the microphone is picking up is coming from the internal device circuitry: the noise changes depending on whether the screen is on or off, and it also changes when, for example, I'm scrolling a page. I think I do not hear this sounds when the device is running LineageOS, but I didn't try it extensively, so I might be wrong.
So, my questions are these:
if these sounds are indeed coming from the circuitry, how is the microphone supposed to deal with them? Is this what the noise cancellation is meant for?
Is there a generic way to enable/configure it?
And why is the upper microphone not capturing these sounds?
Can you recommend me some documentation to learn more about this issue (especially how it's dealt with in Linux or Android)?
Any help will be appreciated For complete reference, I believe that the audio SoC on the Snapdragon 675 is made up with the TI TAS2563 and with the Qualcomm Aqstic wcd937x.

Related

ACER A500 Microphone Fix?

Hi, guys Ive been looking for microphone fix on my A500 , when i record any video it has this loud background noise...which in fact my room is silent , also when I'm recording videos outside & using Skype . Im using HC 3.2.1 rooted with thor's CMW ver 1.5 . I been searching the forum for a fix but i cant find it or so as I read that they will fix this issue on HC 3.2, but still i get this issues . Is this a Hardware problem or OS issue?
Also can I still return this tablet to walmart & get a refund? I already exchange the first 1 cuz It got a charging issue. SO basically I'm returning an exchange tablet. It hasn't been 14 days yet. as they mentioned for returns & refunds.
Thanks.
hatyrei said:
Hi, guys Ive been looking for microphone fix on my A500
Click to expand...
Click to collapse
Funny, I was coming here to ask for help about something similar...
In my case, I have a refurbished A500 which has been awesome so far, with the exception of the microphone. It records terribly, lots of noise and distortion in any recording I make (using Recorder as the test app I made a short .amr recording which I attach 7zip-compressed).
A friend has an A500, and it doesn't seem to display this issue. While it's no deal-breaker (I can live without recording audio...playback of tv shows loaded on the card works better-than-fine!), I'm wondering if there's anything I can do to fix it, or at least make it a little less...noisy.
I believe the culprit has to do with the speakers creating feedback. The workaround is to use headphones. Hope this works for you.
Take a look here:
http://forum.xda-developers.com/showthread.php?t=1065219
tabasco22 said:
Take a look here:
http://forum.xda-developers.com/showthread.php?t=1065219
Click to expand...
Click to collapse
I did read that entire thread, which only tells me there are multiple unrelated issues around audio recording on the A500...these issues seem to get all mixed-together in that thread, with people who only care about Skype focusing on that and cross-talking to people who have completely different recording issues. I was hoping this thread could avoid the whole need-to-use-Skype distraction and focus on the specific issue of seemingly over-driven recordings. (With the refurb, I'm also out of the whole keep-complaining-to-acer-until-they-do-something-to-fix-it focus there seems to be on that thread. I can't really complain, and any warranty I had expired a while ago.)
The earlier suggestion to use a headset is, however, something I should have considered first (even read in the earlier Skype-centric thread), and am a little embarrassed I didn't. Sometime this weekend I'll pick up a cheap 3.5 mic/headphone set and see if that makes any difference. If it does, and the recordings though it are cleaner, I can be more comfortable it will work for one thing I care about...using the A500 with the SquareUp CC processor.
Mic - Solution for me.
Problem: Microphone recordings sound terrible. Soft, Choppy, Mechanical, like a bad cell call, bathroom (NOT the severe helicopter sound as others have reported). My hypothesis like others have suggested, seems to be noise cancellation issues. Especially since the issues vary app to app. These mics are right beside each other and I assume they're pretty much hearing the same thing, and the rear is trying to cancel what it hears, which is the same as the front! End result being filtering what it hears, ie filtering everything? FAIL.
Test 1: Using Recorder and Skype Test call, I tested different distances talking to the front/back, covering front mic, covering back mic, case on, case off, headphones plugged in/out, etc. In some instances you could hear some, and other hear nothing, some sound ok, some sound horrible. I wasn't satisfied with ANY.
Test 2: Popped off back of tablet and disconnected REAR facing mic. They are side/side, make sure you disconnect the correct one, the one with the diaphragm pointing out. Simple connector. Then tried Recorder/Skype Test call and both sounded Excellent. I have not tried a call with Skype, just the test. EDIT: Tested a real Skype call last night. No sound issues on my end or other end.
Conclusion: Removal of rear mic provided the best quality. There is zero filtering/cancellation/etc.
Gotta try this
Hmm!
Should of thought of this myself. Going to give it shot and post back later!
Unhooked the rear mike --it helps the front m ike is usable now. Not perfect but works.
So for me
1 Run Flexreaper ICS by Civato = better mike
2 Drill hole for front mike = not as muffled
3 Disconnect rear mike= almost as good as a phone but not as sensitive.
Okay on recording and search but Skype still noisy without headset.
Damn connectors were a pain to unhook.
appoaf said:
Problem: Microphone recordings sound terrible. Soft, Choppy, Mechanical, like a bad cell call, bathroom (NOT the severe helicopter sound as others have reported). My hypothesis like others have suggested, seems to be noise cancellation issues. Especially since the issues vary app to app. These mics are right beside each other and I assume they're pretty much hearing the same thing, and the rear is trying to cancel what it hears, which is the same as the front! End result being filtering what it hears, ie filtering everything? FAIL.
Test 1: Using Recorder and Skype Test call, I tested different distances talking to the front/back, covering front mic, covering back mic, case on, case off, headphones plugged in/out, etc. In some instances you could hear some, and other hear nothing, some sound ok, some sound horrible. I wasn't satisfied with ANY.
Test 2: Popped off back of tablet and disconnected REAR facing mic. They are side/side, make sure you disconnect the correct one, the one with the diaphragm pointing out. Simple connector. Then tried Recorder/Skype Test call and both sounded Excellent. I have not tried a call with Skype, just the test. EDIT: Tested a real Skype call last night. No sound issues on my end or other end.
Conclusion: Removal of rear mic provided the best quality. There is zero filtering/cancellation/etc.
Click to expand...
Click to collapse
I did and I agree this is a fix if you want to use recorder, Skype, talk, tango, etc. But I also learned to forget using the video camera UNLESS you have it using the rear camera (this is one you use by default when you Skype). Looks like it uses the microphone that points in the direction of the active camera.
So I would suspect the noise cancelling algorithm settings are to blame for poor sound recordings.
I solve this issue by using my stereo earphone with mic that came with my Nokia phone. I have tried a bluetooth stereo headset with mic and another wired earbuds with mic, there was either still a lot of noise or the sound level was very low. Basically, it is the same as using a headset. Finally I found one earphone with mic that works well. I actually have two of the same earbuds from 2 identical Nokia 5230. I tested them on two Iconia A500 with voice chat and video chat, it works very well both ways. I have also tried to turned off the Dolby Mobile as suggested by someone. It actually makes it worse and the sound level went down a lot.
acer a501 microphone fix
hi all
today i finally got to the bottom of the microphone issue
versions 3.x had some issues with the mic that cant be fixed - tried different internal and external mics but no good - i thought it was a hardware issue
and not able to solve but after ota update of ics the external mic is perfect - crystal clear and no noise and heaps of level.
the internal mic is crap so i decided to change the microphone with anything i could find - it has to be electret mic.
I had a few lying around and some worked well and some did not - i eventually found one that worked really well will heaps of level - the
only prob was that it was twice the size of the original.
i had to cut some of the plastic away but eventually got it installed.
The internal mic works great now - much better than the muffled one that came with the unit.
I left the second mic connected as it seems to make no difference in or out.
So what i have found -
firmware on 3.x no good for mic
ics makes mic work well if you use exeternal.
internal mic - get rid of it as it is useless.
hope this helps someone as i spent lots of time trying to fix this
OK but...
jzaiter said:
hi all
today i finally got to the bottom of the microphone issue
versions 3.x had some issues with the mic that cant be fixed - tried different internal and external mics but no good - i thought it was a hardware issue
and not able to solve but after ota update of ics the external mic is perfect - crystal clear and no noise and heaps of level.
the internal mic is crap so i decided to change the microphone with anything i could find - it has to be electret mic.
I had a few lying around and some worked well and some did not - i eventually found one that worked really well will heaps of level - the
only prob was that it was twice the size of the original.
i had to cut some of the plastic away but eventually got it installed.
The internal mic works great now - much better than the muffled one that came with the unit.
I left the second mic connected as it seems to make no difference in or out.
So what i have found -
firmware on 3.x no good for mic
ics makes mic work well if you use exeternal.
internal mic - get rid of it as it is useless.
hope this helps someone as i spent lots of time trying to fix this
Click to expand...
Click to collapse
HoneyComb 3.2 disconnected the rear microphone, Resulted in Better Quality without helicopter noise specially better for skype Etc.
Video recording still Just hardly acceptable. but quality is still bad.
Wont buy from acer anymore.

[working] sound issues and hardware/software link

Hello there everyone.
I am working on few of problems faced by Nexus regarding its sound quality and other issues related to hardware and software. One of the device has confused me completely is been addressed at the end of this thread.
Mostly, according to my experience, the sound is very loud compared to its previous model of Nexus 7 2012 which had mono speakers while this is loaded with two stereo speakers. Using it in portrait mode has best sound experience.
However, if you try the surround sound option via Google Music, the sound isnot really loud. Just without it, I have noticed best performance.
Also, in MX Player Pro, I have seen that with good headphones, you can increase the sound upto 30 (rather than normal 15) yet you can not do the same whilst using the speakers. It could be due to codecs.
Overall, the sound is loud in a quite environment but hardly noticed in busy areas with background noises like streets. shops etc even on its full sound.
However, some devices do have a bit low sound which could be increased by modifying files a bit but this is kind of increasing your speakers output more than it is optimised to be used for. Thus, sound may break and might be distorted. I am trying to find a combination where an optimum balance could be achieved but I haven't been successful. (If anyone has these values, please share)
I havenot come across a speaker problem related to hardware where no sound was coming out of it. Although, few devices do have different maximum sound if measured in db (3 to 5 db on same track)
THE DEVICE
The device came without its top speaker working and after opening it up and checking the speakers, both speakers worked. I thought the reason, it was not working was due to software. I tried looking into it deeply through software modification without any luck.
One day, after heavy gaming out of curiosity, I just turned on songs to check if both speakers were working and viola, both were working out of no where without any software modification (I gave up and reset the Nexus to give it for warranty claim the next day).
I was overjoyed and till next day, both speakers were working perfectly until I did some heavy gaming again and the sound vanished after charging it (It got hot again during charging)
This has happened twice and today I was gaming with sound turned on and nothing. The device top speaker didnot turn on for a second even like two times it happened before. Both that time, my device was silent while gaming.
I suspect some wiring issue but still not sure, I am now a bit sceptical to open this Nexus again and void the warranty as I have already have taken the back lid off few times. I do not intend to heat it with soldering Kit as I have damaged Htc Sensation a while back doing that. Any Suggestions about this device in particular?
How have been your experience with sound quality and do share any mods you have find useful and have tested.

[Question] Microphone Issues - Any ideas?

Hello everyone, I've checked the forums and I've not really seen many answers to this question as it's something that's been bugging me for a while now.
I don't know when it started, but I noticed recently after recording a video and playing back, the sound on one side is completely gone. Almost like Stereo mode has been disabled, I have determined that it is the microphone that is often used during Loudspeaker calls, I tested this by placing a call to a friend on a regular call, then a WhatsApp Call, and finally a Skype call - and each platform is having the same issue - my loudspeaker microphone is not picking up audio. Is there a fix for this? I took apart the device, cleaned thoroughly but I'm wondering if the microphone itself has become busted. If anyone has a similar issue, or has found a fix for this - could you please provide me with some information? I love my Note 3 and would love to start recording some videos again.
Thanks everyone!
Ginger Bearded Guy
Ginger Bearded Guy said:
Hello everyone, I've checked the forums and I've not really seen many answers to this question as it's something that's been bugging me for a while now.
I don't know when it started, but I noticed recently after recording a video and playing back, the sound on one side is completely gone. Almost like Stereo mode has been disabled, I have determined that it is the microphone that is often used during Loudspeaker calls, I tested this by placing a call to a friend on a regular call, then a WhatsApp Call, and finally a Skype call - and each platform is having the same issue - my loudspeaker microphone is not picking up audio. Is there a fix for this? I took apart the device, cleaned thoroughly but I'm wondering if the microphone itself has become busted. If anyone has a similar issue, or has found a fix for this - could you please provide me with some information? I love my Note 3 and would love to start recording some videos again.
Thanks everyone!
Ginger Bearded Guy
Click to expand...
Click to collapse
First factory reset and check again. .if same it s material problem
I've Factory Reset about 10 times since this post, and attempted all kinds of different things. I can confirm that it is a definitely a hardware issue, could you recommend what to do so I can get this fixed? Again, my primary microphone works fine while making calls - it is only when I enable Loudspeaker that the other party is unable to hear me due to the "Top Microphone" on the device not working for some unknown reason. Again, I've attempted cleans, fixes etc - but the issue only occurs during loudspeaker calls and when recording video as the top microphone is used with the primary microphone for Stereo Recording.
I know the microphone still picks up some form of audio but at a very low level - as I have called a friend and enabled loudspeaker and continued on to blowing in the hole where the microphone is situated. They can hear the loud distortion created by the air, but not a voice or anything like that. I really have to shout (And I mean LOUD) if anything audio is to be picked up.

Weird microphone issue?

I am familiar with how many people are dealing with microphone sound issues on their 6P, however mine is a little bit different. My phone had "slight" liquid damage that was repaired by replacing a few parts and drying out. Everything on the phone has been working 100% except for an issue with the microphone.
Initially, there was no sound being recorded on the phone at all, and so I decided to try replacing the daughterboard on the bottom of the phone (where one of the microphones is). Immediately I had sound being recorded again!
However, I have found that I will record sound only from a few particular instances.
This is what works:
Phone call microphone (not speakerphone)
General voice recording apps
Google Now / Assistant
This is what doesn't work:
Camcorder microphone recording
Speakerphone microphone
Hangouts / Duo video calling (will work if i set to 'headset' speaker as opposed to speakerphone)
I am assuming it has something to do with the other microphones on the device, whether they are failing or it has something to do with the noise canceling effects.
Has anyone experienced an issue similar to this on this device (or other devices) and found a solution?
The only other option would be to replace the entire motherboard that contains the other microphone (which happens to be about a $200 part, with new EVERYTHING)
Short of removing and resoldering a replacement 'mic' on that board, is there any software solutions?
I love this phone dearly, and it's especially sad that I cannot even record video of my baby daughter with sound.
Any help would be appreciated!
Thanks,
Nathan

Low volume from wired mic in all custom ROMs

Hello guys and gals
I've been trying a lot of custom ROMs for our beloved 9T, and as is usual they all have their little bugs and quirks, some more some less.
However, one problem I noticed affects ALL custom roms for our device (well, the ones I tried at least) is that the microphone audio from any wired (3.5mm jack) headset has a VERY LOW VOLUME. Whenever I record a voice note in Whatsapp or any other app, or when I have a meeting with Google Meet, or even just recording my voice with a Voice Recorder app, it's extremely quiet, unless I talk right into the mic.
This was not the case on MIUI, so it's clearly a custom ROM issue. I wanted to know a couple of things:
1) I'm not crazy right, external mics DO have low volume on custom ROMs, yes? Or is this some issue specific to my device?
2) Any workarounds/solutions you can suggest?
By scouring the forums and searching on google, I think the problem is some misconfiguration in the /vendor/etc/mixer_paths_idp.xml file, however I have no clue which values to modify, since from what I read the values you should change are different depending on the device.
Any help or suggestion on this matter would be appreciated.

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