MT6739 Sound recording issues

Hello everyone
Recently, I used the recording function of my watch. Because the system’s built-in recorder will end recording when the screen is turned off, I downloaded some other recorders, but
I found that I couldn’t record after turning off the screen.

The specific performance is that when turn off the screen, recorded sound like to turn on fast forward, the sound is incomplete and intermittent.

At first I thought it was a watch problem (LEM8), but then I tried LEM10, X365 and kospet Prime again and found that they were all the same problem. At the same time, they are all MT6739 platform products.

I tried almost all the recording app in Google play,and found that none of them can be used in the watch, which is really distressing.

So how can i do? MT6739 hardware? Android 7.1? Or a recording app?

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I just checked my Lem 10 and it continues to record after the 30 second time out my display is set for. I think your problem may be that the Sound Recorder is not disabled in the Battery Saver. This means it can turn off when the screen goes off. Its been 2:26 minutes and mine is still running.

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Thank you, my problem is not that the recorder does not work properly, but that the sound recorded by the recording app is distorted when the screen is turned off. Distortion of the recording occurs within 2-3 minutes of turning off the screen.

I decided to check the Battery Saver setting on my watch and found it is not listed, so that would not be an issue. In your initial post you said, “Because the system’s built-in recorder will end recording when the screen is turned off,” and I was responding to that statement. If you have a distorted sound problem that sounds more like a hardware issue to me.
(I find it a bit unusual that all your watches have the same problem? All the watches I have owned the Sound Recorder worked good. I recently recorded some music at a live concert and it worked fine.)

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If using the system’s recorder, can your LEM10 turn off the screen while recording?
My LEM10 will always light up the screen when I use the system’s recorder. If I press the home button, the recording will end immediately.

No I cannot turn off the screen and it doesn’t time out while recording. I would think that the screen must stay on while recording and never considered it an issue.

I just checked my Lemfo Les 1 and the screen does turn off and continue to record but it is running Android 5.1 OS.

I also checked my Lemfo Lem 7 and it also turns off and continues to record. It is running Android 7.0.
I also noticed the Sound Recorder in both of those watches have the app that has a white background with blue layer at the bottom.

I checked my Lemfo Lem 11 and it is identical to the Lem 10 as it stops when I “lock” the screen and asks if you want to save the file when you re-start the watch. It also has the same black background as the Lem 10. So maybe it is a characteristic of their MT3769 processor?

Hi, @karma , I have exactly same problem with Kospet Hope. It’s not hardware problem , it starts recording in fast forward, I found out this problem a year back and didn’t find any solution.
Best regards

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Update: I downloaded two recorders from the PS. Smart Recorder and Voice Recorder and tested them in my phone. Both kept recording after the screen went off. So I transfer the apps to my Lem 10.
The Smart Recorder app would not install on my watch. Got a “Did not install” message after attempted installation. I installed the Voice Recorder app and it installed. Opened the app and set up to record. After 30 seconds, (my timeout setting) the screen went off.I let it run for over a minute. When I played back the recording it had recorded the full time. But the sound as you experienced was fast forwarded and not usable. Since the apps worked on my phone, it would be my guess that this has something to do with Google and the restrictions they have set up that affect these devices. Similar to BT call no longer being able to function.

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Yes, @Jonathan_Bickel good day ! I also tried different apps. but no use .
Best regards

Yes it is unfortunate but the Sound Recorder App on my watch works fine. Keeping the screen on is obliviously how they are getting around the issue. The only time it would make a difference is if you were recording and did not want anyone to know it? That is why maybe they changed the background color of the app from White on older models to black where is it a lot less conspicuous and at low brightness barely noticeable…

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Yeah , you are right @Jonathan_Bickel as recording is illegal with out permission.

Yes some use can be illegal, not recording itself. That’s why the app should work. And it works well on a smartphone.

Call recording, yes, illegal in many countries without authorization.

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Of course it depends where you are located. In the US there are federal statutes and state laws. In general this applies: Illegal Recording Under the Wiretap Act

Under the federal Wiretap Act, it is illegal for any person to secretly record an oral, telephonic, or electronic communication that other parties to the communication reasonably expect to be private. (18 U.S.C. § 2511.)
There are exceptions and again each state may have their own laws affecting recording. The bottom line is know the law.
If you are just recording a conversation for your own use, such as a reference to be used later to clarify what was said probably not a problem. But if you are trying to catch someone breaking the law or implicating themselves for something you are probably on thin ice trying to use a secreted recording.

Also the app works, on my watches, you just can’t turn the screen off and keep recording.


I think it has some thing to do with processor speed , as it reduces on turning off the screen and it also effects the speed of recording. The recording is not garbage but speed of play back is increased, so if you have recorded in slow speed then while play back in normal speed , the speed of recorded audio will increases dramatically and same app. works fine on mobile. I am not expert in software but logically considering facts , I think it explains the problem.
Best regards


I think I found where is the problem, but I cannot guarantee that this is the truth.
MT6739 After turning off the screen, the CPU will reduce the frequency within a certain period of time.The time for sound recording files to be stored in the buffer will increase when the CPU reduced the frequency. But various sound recoding apps has not been optimized for this situation, they buffer is still superimposed according to the original time, which causes the buffer file is lost, and finally you get intermittent recording files.
This is a minority problem caused by the watch’s extreme power saving strategy, but watch manufacturers have no intention to solve this problem. Ordinary APP authors don’t seem to think about adapting for watches.