Database Develop

Possible workaround for a noisy mic

The microphone for the Nexus 4 is very noisy. A user on another thread described a video he recorded
to sound as if it was "recorded underwater".
I looked up the Android SDK and the MediaRecorder object has access to the following audio streams:
CAMCORDER, DEFAULT, MIC, VOICE_CALL, VOICE_COMMUNICATION, VOICE_DOWNLINK, VOICE_RECOGNITION, VOICE_UPLINK.
http://developer.android.com/reference/android/media/MediaRecorder.AudioSource.html
I noticed that while audio and video recorders sound bad on Nexus4, voice calls are of decent quality.
Not all phones have the hardware to handle all these so most sound recorders use MIC or DEFAULT.
I found the source code to the MIUI Sound Recorder and it was easy to add a setting that lets you
manually select which hardware stream to record from.
I ran some tests on the Nexus 4 and came to the following conclusions:
- MIC, DEFAULT and VOICE RECOGNITION are probably the same stream and sound bad.
- the CAMCORDER audio stream is the cleanest.
I propose that until Google and LG fix this issue ROM developers alter the Android API on Nexus 4 (only)
so that the CAMCORDER stream always overwrites MIC and DEFAULT.
I'm attaching the modified MIUI Sound Recorder with manual stream select if anyone wants to do
tests on their own. Here's an amplified view of MIC vs CAMCORDER.

-Mindroid- said:
The microphone for the Nexus 4 is very noisy. A user on another thread described a video he recorded
to sound as if it was "recorded underwater".
I looked up the Android SDK and the MediaRecorder object has access to the following audio streams:
CAMCORDER, DEFAULT, MIC, VOICE_CALL, VOICE_COMMUNICATION, VOICE_DOWNLINK, VOICE_RECOGNITION, VOICE_UPLINK.
http://developer.android.com/reference/android/media/MediaRecorder.AudioSource.html
I noticed that while audio and video recorders sound bad on Nexus4, voice calls are of decent quality.
Not all phones have the hardware to handle all these so most sound recorders use MIC or DEFAULT.
I found the source code to the MIUI Sound Recorder and it was easy to add a setting that lets you
manually select which hardware stream to record from.
I ran some tests on the Nexus 4 and came to the following conclusions:
- MIC, DEFAULT and VOICE RECOGNITION are probably the same stream and sound bad.
- the CAMCORDER audio stream is the cleanest.
I propose that until Google and LG fix this issue ROM developers alter the Android API on Nexus 4 (only)
so that the CAMCORDER stream always overwrites MIC and DEFAULT.
I'm attaching the modified MIUI Sound Recorder with manual stream select if anyone wants to do
tests on their own. Here's an amplified view of MIC vs CAMCORDER.
Click to expand...
Click to collapse
I modified my kernel to fix this and I used your apk to test for both mic and camcorder and I don't notice the difference with my updated kernel.
http://faux.androidro.ms/mako/beta/mako-jb-kernel-004b06.zip
check for me to see if I really fix it or not since I am not an audio expert

Thank you, faux!
I've been meaning to try your kernel for a while so now I just have to.
Please treat my ideas about how Android exposes the audio stream as a speculation for now.
I didn't run any in-depth tests and I didn't trace the kernel code.
To my ears the MIC/DEFAULT streams are very noisy. The CAMCORDER one is noisy also
and but somewhat less so. They all sound bandpassed (probably a microphone limitation).
I'd like to know what other users think of the sound.

Very interesting.
I agree that N4 mic is so sensitive that it picks up a lot of background noises. I have been tweaking with mic volume to offset it.
If OP is true, then there's a hope for VoIP users who use Csipsimple. Without changing the kernel, csip can use CAMCORDER mode by changing the settings under media>audio troubleshooting.

The very high mic gain is the main issue with the sound quality. It needs to be adjusted from
the kernel driver which is not a trivial procedure. Gain from apps works on top of the hardware
gain and does not affect distortion that happens earlier in the signal chain.
One user put scotch tape on the mic to mechanically attenuate the sound and reported good results.

If the the sound system on the nexus 4 is built on top of ALSA, I.e. if the directory /proc/asound exists, then microphone levels can be adjusted in user-space. There is an app (ALSAMixer) available on the market that could be used here.

What would be the effect of covering the mic with something to reduce it's sensitivity?

chdloc said:
If the the sound system on the nexus 4 is built on top of ALSA, I.e. if the directory /proc/asound exists, then microphone levels can be adjusted in user-space. There is an app (ALSAMixer) available on the market that could be used here.
Click to expand...
Click to collapse
I'm not sure if that will do it. The textbook audio recording chain goes like this:
microphone -> preamp -> analog-to-digital converter
If I'm not mistaken ALSA(the driver) will take over afterwards. We need a way to control
the hardware gain on the preamp. It's possible that preamp gain is permanently fixed by design.
On the other hand almost all modern preamps have automatic variable gain so it might just be
a matter of figuring out how to turn it on.
EDIT:
ALSAMixer doesn't work at all on my phone (stock 4.2.1 - rooted)
Do you know of any custom kernels for the Nexus4 that use ALSA?
donec said:
What would be the effect of covering the mic with something to reduce it's sensitivity?
Click to expand...
Click to collapse
Aside from the ugly look it should work OK. I would suggest using some kind of soft thread fabric.
Wool is one of the best materials for sound absorption but you should try different materials.
The downside is that mechanical methods don't attenuate all frequencies linearly - they work much better
on higher frequencies so you will have to try and see what material works best.
If this works out it would be ideal to open the phone and plug the microphone hole on the inside with the proper material.

I don't have a Nexus 4, but I do know that the Nexus 7 uses ALSA. Have you checked for /proc/asound? If it exists, then you may need the proper ALSA libraries first.
Sent from my Nexus One using xda app-developers app

im starting to think LG just used cheap mics to keep cost down. From the buzzing to the sub par recording quality

-Mindroid- said:
Aside from the ugly look it should work OK. I would suggest using some kind of soft thread fabric.
Wool is one of the best materials for sound absorption but you should try different materials.
The downside is that mechanical methods don't attenuate all frequencies linearly - they work much better
on higher frequencies so you will have to try and see what material works best.
If this works out it would be ideal to open the phone and plug the microphone hole on the inside with the proper material.
Click to expand...
Click to collapse
I have my Nexus 4 in a case and thought maybe I could improve the quality by placing a piece of cloth between the case and the phone.

Lockeskidney said:
im starting to think LG just used cheap mics to keep cost down. From the buzzing to the sub par recording quality
Click to expand...
Click to collapse
The specs for the microphone do not look bad either. http://www.knowles.com/search/prods_pdf/SPU0410LR5H.pdf is the spec sheet and it should be working to 116 dB, which is louder than I'd want to be in - though it is only the loud end of rock concerts. Noise also looks okay on the spec sheet, but you cannot expect Schoeps quality of course..
The underwater sounds I'm hearing with the sound recording tool remind me of processing, heavy compression andf such. Not what I heard on my camcorder tests, which had a pleasant sound.
Overload is more likelely to be caused by audio codec settings. A voice call has the mouth close to the mic, that is loud too, and works well. But applications like movie recordings crank up the gain to record sounds further away.

jutezak said:
The specs for the microphone do not look bad either. http://dl-bacon.bbqdroid.org/GeebCM/EN_LG-E973_SVC_ENG_121127.pdf is the spec sheet and it should be working to 116 dB, which is louder than I'd want to be in. Noise also looks okay on the spec sheet, but you cannot expect Schoeps quality of course..
The underwater sounds I'm hearing with the sound recording tool remind me of processing, heavy compression andf such. Not what I heard on my camcorder tests, which had a pleasant sound.
Overload is more likelely to be caused by audio codec settings. A voice call has the mouth close to the mic, that is loud too, and works well. But applications like movie recordings crank up the gain to record sounds further away.
Click to expand...
Click to collapse
Nice find! Thank you for sharing!
Microphones in general are almost never bad. It's the preamps and digital processing that add more to the mix.
Regarding the "underwater" sound I now suspect a lack of a Low Pass filter. Check out my other thread:
http://forum.xda-developers.com/showpost.php?p=36856100&postcount=18

jutezak said:
The specs for the microphone do not look bad either. http://www.knowles.com/search/prods_pdf/SPU0410LR5H.pdf is the spec sheet and it should be working to 116 dB, which is louder than I'd want to be in - though it is only the loud end of rock concerts. Noise also looks okay on the spec sheet, but you cannot expect Schoeps quality of course..
Click to expand...
Click to collapse
Human speech can generate 116dB SPL measured at 1-2" distance fairly easily. I just measured the level my speech at 1" distance (with a lab-grade device) and I did not have to shout to produce 116dB SPL. The spec sheet says that the microphone produces about 10% THD typically at 118SPL for a 1kHz tone.
jutezak said:
Overload is more likelely to be caused by audio codec settings. A voice call has the mouth close to the mic, that is loud too, and works well. But applications like movie recordings crank up the gain to record sounds further away.
Click to expand...
Click to collapse
Distortion of the microphone signal is generated (or amplified) in at least four locations:
1. The microphone itself (analog or digital if the microphone is a digital microphone as many MEMS are; the above referenced Knowles mike is analog)
2. The amplifier (analog)
3. The analog-to-digital converter (ADC) which is spec'ed with a maximum input voltage to generate a signal that hits "digital rail", i.e. 0dB FS (full-scale)
4. digital gain along the digital processing path
Potential "clipping" (i.e. signals producing 0dB FS at the ADC) can only be avoided if the analog amplifier (if there is one) can be controlled. By looking at the ALSA mixer settings for the Nexus 4 my only hope lies in the controls that are labeled "ADCX Volume" where X=[1,6], i.e. numid. I believe -Mindroid- shared his "idle" settings vs. settings during a call and only X={1,3}, i.e. numid={48,50} have changed. Give changing those two parameters a try...

I posted this in a different thread, but thought it would be useful here as well as a potential lead to a workaround:
Looks like the audio chip in question is a Qualcomm WCD9310.
It's used in a few other devices as well (eg: GS3 USA). If their audio runs fine, perhaps we could try running their audio drivers on our device?

[Q] [Mod]Use Second Speaker on Xperia Z for Stereo Sound (Like Tablet Z)

Hey Dudes/Dev's
What i want:
I want to Create a Mod which us allow to use the Front Speaker+Side Speaker for Stereo Music
See Attached Pic...
I have tested the Loudness of the Front Speaker and i think the Volume Level is nearly the same to the Side Speaker!(?)
I want to let the Music play over the 2 Speakers like:
Front (Call-)Speaker=Left Audio Channel + Side (Loud-)Speaker=Right Channel=Stereo!?
Click to expand...
Click to collapse
Steps:
-1. Find files which include the Speaker config. Maybe lib-so files?
-2. Find the right way to edit. Maybe i can compare the files between Tablet Z and Xperia Z to find the diffrence?
-#. Edit files to -> Playing Music-> 2 Speaker's active (2 Channels Left-Right),Call Option1-> 1 Speaker active,Call Option2-> 2 Speaker active
-3. Find a Way to make both Speaker's to the same Loudness Level
maybe more...
I really don't know what's needed for this so Please Help!
BR

Good idea

Another excellent idea, though sound when watching movies is allready pretty good, true stereo imaging would be a massive plus.
Good luck with this
Sent from my XZ C6603 - 4.2.2 HK. (UK Generic)

Thanks Guys!:fingers-crossed: only a thing of time
To bad that here is still no Dev. Section for things like that. This Thread will go fast to the last pages,and no one will see
BR:angel:

Sounds like a good idea but then again, earpiece is not nearly as powerful as the main speaker and can result in funny stereo audio lol FYI, the stereo speaker positions are a bit weird
In order to achieve in what you want, we need to route all audio playback to play on two channels which is the earpiece and speaker at the same time. We can either do this on a specific configuration file or kernel modifications. I am not sure how to do this as I haven't tried before but it's a start
It's too bad that Sony did not make two speakers positioned like the HTC one... Would of been epic...
Swiped from my Xperia Z (C6603)

you have amazing brain
good idea

ZeroInfinity said:
Sounds like a good idea but then again, earpiece is not nearly as powerful as the main speaker and can result in funny stereo audio lol FYI, the stereo speaker positions are a bit weird
In order to achieve in what you want, we need to route all audio playback to play on two channels which is the earpiece and speaker at the same time. We can either do this on a specific configuration file or kernel modifications. I am not sure how to do this as I haven't tried before but it's a start
It's too bad that Sony did not make two speakers positioned like the HTC one... Would of been epic...
Swiped from my Xperia Z (C6603)
Click to expand...
Click to collapse
wow didnt see you Replied to this thread nice to hear from you...
It's really bad with the Speaker Position... sometimes my right hand mute the Speaker
but back to the idea... it's like you say,the Earpiece is not really Powerful (It's a really Clear Speaker,but no Bass) so you think it's not loud enough for stereo? Maybe we can use it to Support the other speaker (more Virtual Sound or such,i think you know whats good )
The Point is still to find out how we can use the second speaker :crying:
the only idea i have is to find the related files and watch the same files on a Stereo Speaker Tablet to see what we need to change...
when it works we have really found a General Mod for a lot of Devices with low Volume Speaker Devices.
B.R.
Miustone

Miustone said:
wow didnt see you Replied to this thread nice to hear from you...
It's really bad with the Speaker Position... sometimes my right hand mute the Speaker
but back to the idea... it's like you say,the Earpiece is not really Powerful (It's a really Clear Speaker,but no Bass) so you think it's not loud enough for stereo? Maybe we can use it to Support the other speaker (more Virtual Sound or such,i think you know whats good )
The Point is still to find out how we can use the second speaker :crying:
the only idea i have is to find the related files and watch the same files on a Stereo Speaker Tablet to see what we need to change...
when it works we have really found a General Mod for a lot of Devices with low Volume Speaker Devices.
B.R.
Miustone
Click to expand...
Click to collapse
You won't find any related files which will route your speaker and earpiece together.
We need to re-route the audio playback with earpiece and speaker activated at the same time to make both speakers to sound like stereo. If you compare with Tablet Z, you will not find anything because the configurations for that is to route audio playback to both the speaker components and if we do that then it still won't work because we don't have that 2nd speaker.
If we can re-route the speakers into stereo, then we can manually increase the earpiece to make it sound as loud as the main speaker
This is just an idea remember, I don't actually know how we will do this

Any progress on this excellent idea?

Found mod
http://forum.xda-developers.com/xperia-z/themes-apps/mod-stereomod-xz-v1-1-t2835995

ZeroInfinity said:
You won't find any related files which will route your speaker and earpiece together.
We need to re-route the audio playback with earpiece and speaker activated at the same time to make both speakers to sound like stereo. If you compare with Tablet Z, you will not find anything because the configurations for that is to route audio playback to both the speaker components and if we do that then it still won't work because we don't have that 2nd speaker.
If we can re-route the speakers into stereo, then we can manually increase the earpiece to make it sound as loud as the main speaker
This is just an idea remember, I don't actually know how we will do this
Click to expand...
Click to collapse
Was just using My Mix 2 with this Method of Speaker usage and was remembering You and this Thread... It is so Popular right now, sad we don't have the Patent on it Mate :laugh: Loved to use Your work back in the Days <3
Just in Theory. If i would Create a Modern Smartphone... You would be the Man for the Audio Stuff. Giving 100% freedom in creativity and access to OEM exclusive Sources and Knowledge. I can Image that Device would be Mindbreaking...

Stereo speaker mods?

So now that the the S8+ has been rooted, is there anyone working on a mod to enable the earpiece as a second speaker? When I had the nexus 5x, I immediately went for the stereo mod after rooting. The earpiece obviously wasn't as great but it was nice to have it anyways.

Sound mod dual speaker??

I wanna know if there is a mod which I can increase the volume and use both speakers.
thank you for your time

? up

Xda has a very good search engine !
Sent from my Galaxy Note8 using XDA Labs

Yes, you can activate dual sound output and use two different Bluetooth speakers at the same time, but unfortunately there is a slight delay between them which create a weird effect. It is true that I have tried this with two different type of speakers (a Philips AS 141 and a Samsung Level Box slim), maybe with two identical Bluetooth devices it would work better.

There is a mod (and a thread for the mod) which will allow the use of both speakers as stereo - however you can't increase the volume much (if at all) over the default because the earpiece speaker is not designed to be used that loudly - you will get distortion and crackles, and potentially damage the speaker.
You can ask in the relevant thread if the dev can sort out a louder version for you, but personally I'd stick to the prescribed limits, as it will affect sound quality quite (very, depending on how much of an audiophile you are) badly.
You'll have to be rooted for the mod to work as well, so bear that in mind.
e: https://forum.xda-developers.com/galaxy-note-8/themes/dual-speaker-mod-note8-exynos-t3676091
There you go, right at the top of the mods/apps/themes section...

Why not just get one of those tiny speakers on amazon you plug in to the headphone jack ?
www.amazon.co.uk/gp/aw/d/B007NJ3SIM...67e265c11d28&pd_rd_w=s7fIw&pd_rd_i=B007NJ3SIM

◇Stereo Dual Speakers Surround Sound♤N910F/T/P/V/G/W8♤N910C/H

DISCLAIMER=WARNING PLEASE FLASH ON YOUR OWN RISK AND MAKE SURE TO HAVE A BACKUP ROM BEFORE TRY IT JUST INCASE IF ANYTHING GOES WRONG.AND DONT BLAME ME IF YOUR SPEAKERS OR EARS DAMAGE BY THIS MOD IF YOU RAISE VOLUME TO MAX BECAUSE IT'S EXTREMELY LOUD.
Hello xda members.
If you want to get surround volume stereo speakers from note 4 like iphone7+/htc boom sound stereo this is a right place this mod will give you stereo surround sound from back speaker and front ear speaker and surround loud sound from headphones and also when your phone will ring the ring tone and notification sound will come from both back and front speakers
AFTER FLASHING IF YOU WANT TO CONFIRM THAT BOTH SPEAKERS FRONT AND BACK WORKING TOGETHER JUST PLAY ANY SONG OR RING TONE THEN COVER THE BACK MAIN SPEAKER WITH YOUR FINGER THEN YOU CAN HEAR SOUND COMING FROM FRONT EAR SPEAKER TOO. FRONT EAR SPEAKER VOLUME IS NOT LOUD OBVIOUSLY BECAUSE ITS NOT AN SPEAKER BUT WHEN YOU PLAY SONG THE SURROUND EFFECT YOU WILL GET FROM COMBINATION OF BOTH SPEAKERS ITS JUST AMAZING.
You must have custom recovery installed such as TWRP OR CWM in order to flash the zip file.
THIS WILL WORK ONLY WITH ALL TOUCHWIZ ROMS THAT I'VE TESTED SO FAR IT WILL NOT WORK I REPEAT IT WILL NOT WORK WITH AOSP MIUI OR ANY OTHER ROMS.
FOR USA ALL MODELS FILES BELOW THE FILE NAME SHOWS TMO TMOBILE BUT IT WORKS FOR ALL USA MODELS OF NOTE 4 I'VE TESTED ON N910P/V/T/W8.
FOR EXYNOS SM-N910C/H GO TO LINK BELOW
https://forum.xda-developers.com/note-4/general/dual-speaker-mod-exynos-n910c-testers-t3839238
FOR N910F/G OR IF YOU HAVE NOTE EDGE GO TO LINK BELOW.
https://forum.xda-developers.com/showpost.php?p=57102722&postcount=2
THIS IS FOR USA SNAPDRAGON N910T/P/V/W8 MODELS BELOW.
1 WARNING THIS IS VERY LOUD STEREO SURROUND IT CAN DAMAGE YOUR SPEAKERS IF YOU RAISE VOLUME TO MAX.
https://mega.nz/#!6VdCAbTQ!PZ_HwIJsPt4LOTKhFhTa3XZfRVAuNM54hg_6EXysRjo
2 THIS IS MEDIUM VOLUME STEREO SORROUND BUT HIGHER THEN STOCK.
BTW THIS 1 IS MY FAVORITE
https://mega.nz/#!DVMGBJwK!Rjy2QbmgNixPOXrC0yPnCL-JFiO2fYt33qSeV2_BTuE
3 IF YOU LIKE STOCK VOLUME AND STILL WANT STEREO SURROUND VOLUME THIS IS BEST FOR YOU.
https://mega.nz/#!3BsQHaQQ!P_2kDVGnZmLyWC9qXLd8WI-kKNJLYm24pZhubGuGt4Y
CREDITS GOES TO @sshafranko
Orignal post link below for many more samsung models supported.
https://forum.xda-developers.com/note-edge/development/mod-sm-915t-surround-sound-t2955648
I AM LOVING MY NOTE 4 AGAIN IN 2018 AFTER FLASHING THIS MOD IT'S JUST AMAZING.
INSTALL POWERAMP MUSIC PLAYER AND FEEL THE POWER OF HEADPHONES .
HIT ME THUMBS UP IF YOU LIKE IT:good::good::good:

@ Trex888 Thanks a lot tried the medium volume for N910F and works great, but curiously how safe is the front speaker with using this mod for a long term use?

@mcfotty: Even Chinese smartphone makers test their phone with loudspeaker ON for hours. I am sure the Note4's earpiece speaker also went through rigorous testing, and some folks just use the loudspeaker all the time.
My device is like 3 years old now, getting slower and slower every day. At least there is something I can still get out of it. So, why not?
(Nvm just read N910C does not work. RIP.)

mcfotty said:
@ Trex888 Thanks a lot tried the medium volume for N910F and works great, but curiously how safe is the front speaker with using this mod for a long term use?
Click to expand...
Click to collapse
I am using this mod from over 3 months and no issues so far with speakers.
Just dont raise volume to max for too long it could possibly distorted the speaker sound.

Appreciate all your kind and timely responds and wondering if you can make this mod for n9100.....thanks

mcfotty said:
Appreciate all your kind and timely responds and wondering if you can make this mod for n9100.....thanks
Click to expand...
Click to collapse
i am not the 1 who create this mod you should contact to @sshafranko so he can create this mod for SM-N9100.

N910c not working

khaledreno said:
N910c not working
Click to expand...
Click to collapse
Which rom are you using ? And which android version ?

khaledreno said:
N910c not working
Click to expand...
Click to collapse
Same here... 910c not working on nemesis refined rom android 6.01... Sad...
Sent from my [device_name] using XDA-Developers Legacy app

I still loving my N910C! It is probably the best phone that I have ever purchased.

Not working on n910c erobot rom

Thanks for sharing this! On my 910T (Magma UX 1.0), using the loud version, it definitely works, but the rear speaker still over-powers the earpiece so it seems like it's not really working. Is this how it is supposed to be, or should the two volumes be more balanced? Thanks!

lesterf said:
Thanks for sharing this! On my 910T (Magma UX 1.0), using the loud version, it definitely works, but the rear speaker still over-powers the earpiece so it seems like it's not really working. Is this how it is supposed to be, or should the two volumes be more balanced? Thanks!
Click to expand...
Click to collapse
It's because front earpiece is not an speaker. the volume will be low because if it's loud it can damaged easily

Just replace the mixer path file (in the zip file) manually from N910F version on the N9100(dual sim Chn) and working great. Thanks for sharing the mod

Just tweak it for myself
Hi, can somebody tell me how to edin the power of back speaker (make it quiet) to "feel more stereo". What do I have to edit ? I see in etc two different mixer_paths. Thanks.

quletadik23 said:
Not working on n910c erobot rom
Click to expand...
Click to collapse
Dual Speaker Mod has been fixed and working 100% now on N910C.
https://forum.xda-developers.com/note-4/general/dual-speaker-mod-exynos-n910c-testers-t3839238

I've flashed the Medium and Regular zips via TWRP on my N910T (tried both), but only the ear piece speaker is firing. There is no sound out the of main speakers. I'm running the OvrDrive ROM and stock kernel.
Any ideas?
Thanks. :good:

iunlock said:
I've flashed the Medium and Regular zips via TWRP on my N910T (tried both), but only the ear piece speaker is firing. There is no sound out the of main speakers. I'm running the OvrDrive ROM and stock kernel.
Any ideas?
Thanks. :good:
Click to expand...
Click to collapse
If you have viper4android or dolby then it may be the issue
On stock working perfectly

Trex888 said:
If you have viper4android or dolby then it may be the issue
On stock working perfectly
Click to expand...
Click to collapse
Hmm ... yea I don't have either and I've even re-Odin'ed the stock firmware again just to be sure....
This is so strange. If all else fails on the software end of things then it's 'gotta' be hardware related... I'll report back after replacing the speaker to see if in fact it is a hardware issue....

Is there any mod for aosp pie rom?