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I have a MTCD/MTCE head unit from Witson(MX) and i'm using the latest Malaysk rom and Mcu(1.75) for my unit.
I can hear a low pitched static noise from speakers when car is silent. It's not loud, but i can hear it. I just realised source of this static is LCD screen. If I decrease brightness of LCD or completely shutdown LCD the static noise came from speaker stops. The sound is even changing with respect to colors on LCD.
My question is: I don't want to return my unit. Can someone with technical knowledge say me how can i solve this problem? Should i install some kind of filter on speaker cables? Should i ground case of the unit or Lcd?
I have the same noise, I didn’t do anything about it because I never have a situation without listening to something. When I drive it’s impossible to hear it.
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Interesting. I have the same noise but haven’t figured out what causes it. I’ll check your LCD theory tomorrow.
a) I have PCB mounted quadlock (VW) on rear of HU
b) i have factory fitted amp in skoda superb ii (VW quadlock - not RCAs used)
c) with aftermarket HU, the amp is turned on when the key is in ignition position and not controlled by canbus like with original
** this is have a very faint hiss from the unbalanced line input being on without a source, but is not the noise we are referring to here **
d) noise is not present if i put back Chinese WinCE HU or original RNS315
e) there is no noise during initial boot screen, or car logo or even during loading of Car Loader AG (inc with HA rom) from cold boot
f) shortly after the Loader screen, the +/- volume keys become active - this is when the noise starts (motor running or not - the noise is the same)
g) if you put the car in reverse prior to turning on, you see white lines about 1cm apart before the vol +/- is activated.
h) once the volume is activated, the noise includes a clicking of about 150-180 bpm (the white lines on the reverse camera flicker to this beat as well)
i) using factory settings/touch keys to config pwr key for short press screen off / long press pwr off and the screen off does not affect noise.
j) changing the factory settings/other/amp gain from 0 to -12db or -15db lowers the noise gain but requires increase volume to overcome the noise.
k) the noise varies and fluctuates with changes in the menu e.g. scrolling and display e.g. download % counter changes
l) the noise varies and fluctuates with touches to the touch screen
m) the noise does not change in amplitude with changes to the system volume control
I have seen a thread where it is suggested, that the interference is coming from the LCD screen and can be verified by turning the screen off - see g) above
** the other thing i am suspicious about is the grounding. I am connected through Quadlock, but trying to power via the Quadlock on a bench doesn't work. Only via
the white connector with the RCAs. says to me something funny going on with either the power or ground wiring. **
Based on all the above, it seems fairly clear that the issue is either the LCD/CPU or some other RF component inducing the noise into the system. i.e. design fault.
I don't have an oscilloscope so can't probe if the noise is on the LCD cables or being induced by the screen RFI without shielding.
Simple test might be to remove the front screen (while still plugged in) and extend the cable moving the screen as far as possible, possible place a metal sheet behind the screen and in front of the unit, to see if the noise changes.. That would at least tell if it is a shielding problem with the screen.
i am surprised there is no solution to this so far, as it is commonly reported among various brands of the PX5 Android boxes.
I am going away, so wont be able to look at this for a few weeks, but would like to hear from anybody who is game to try removing the screen from the case initially.
gwaitsi said:
a) I have PCB mounted quadlock (VW) on rear of HU
b) i have factory fitted amp in skoda superb ii (VW quadlock - not RCAs used)
c) with aftermarket HU, the amp is turned on when the key is in ignition position and not controlled by canbus like with original
** this is have a very faint hiss from the unbalanced line input being on without a source, but is not the noise we are referring to here **
d) noise is not present if i put back Chinese WinCE HU or original RNS315
e) there is no noise during initial boot screen, or car logo or even during loading of Car Loader AG (inc with HA rom) from cold boot
f) shortly after the Loader screen, the +/- volume keys become active - this is when the noise starts (motor running or not - the noise is the same)
g) if you put the car in reverse prior to turning on, you see white lines about 1cm apart before the vol +/- is activated.
h) once the volume is activated, the noise includes a clicking of about 150-180 bpm (the white lines on the reverse camera flicker to this beat as well)
i) using factory settings/touch keys to config pwr key for short press screen off / long press pwr off and the screen off does not affect noise.
j) changing the factory settings/other/amp gain from 0 to -12db or -15db lowers the noise gain but requires increase volume to overcome the noise.
k) the noise varies and fluctuates with changes in the menu e.g. scrolling and display e.g. download % counter changes
l) the noise varies and fluctuates with touches to the touch screen
m) the noise does not change in amplitude with changes to the system volume control
I have seen a thread where it is suggested, that the interference is coming from the LCD screen and can be verified by turning the screen off - see g) above
** the other thing i am suspicious about is the grounding. I am connected through Quadlock, but trying to power via the Quadlock on a bench doesn't work. Only via
the white connector with the RCAs. says to me something funny going on with either the power or ground wiring. **
Based on all the above, it seems fairly clear that the issue is either the LCD/CPU or some other RF component inducing the noise into the system. i.e. design fault.
I don't have an oscilloscope so can't probe if the noise is on the LCD cables or being induced by the screen RFI without shielding.
Simple test might be to remove the front screen (while still plugged in) and extend the cable moving the screen as far as possible, possible place a metal sheet behind the screen and in front of the unit, to see if the noise changes.. That would at least tell if it is a shielding problem with the screen.
i am surprised there is no solution to this so far, as it is commonly reported among various brands of the PX5 Android boxes.
I am going away, so wont be able to look at this for a few weeks, but would like to hear from anybody who is game to try removing the screen from the case initially.
Click to expand...
Click to collapse
It's not the LCD, at least on my unit. The noise is much higher if I connect a flash memory to one of the USB connectors. I can hear the noise as Android is reading the memory content. I think the noise from the digital domain is getting to the analog path somehow. Would be interesting to install some power filters for the analog part or play with the grounding. May do it later if I can find some free time... I do have an oscilloscope but I don't have the time for the research yet...
G0bl1n said:
It's not the LCD, at least on my unit. The noise is much higher if I connect a flash memory to one of the USB connectors. I can hear the noise as Android is reading the memory content. I think the noise from the digital domain is getting to the analog path somehow. Would be interesting to install some power filters for the analog part or play with the grounding. May do it later if I can find some free time... I do have an oscilloscope but I don't have the time for the research yet...
Click to expand...
Click to collapse
I found it easier to track down with a signal tracer, i.e. a probe connected to an audio amp and headphones.
xdamember2 said:
I found it easier to track down with a signal tracer, i.e. a probe connected to an audio amp and headphones.
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I removed the main board from my unit. Bottom layer on the PCB is filled with a ground plane but has many connections cutting through it. I'm wondering if they have a dedicated ground plane as a middle layer. If they don't it's possible there are ground loops which can cause the noice. I will try to add some wires to improve the grounding. Will update when I have any info.
i can hear static too but from my little speaker that produces the parking sensors and indicators sounds.. when the unit seems to be processing i can also hear some. Let us know later @G0bl1n.
Hello, I have the noise when the car radio is connected to wifi or bluetooth
Guys...check your Wifi angena on the back....it makes this annoying noise. Change wifi antenat to external on the cable.....it fixes issue 100%
BoNt3k said:
Guys...check your Wifi angena on the back....it makes this annoying noise. Change wifi antenat to external on the cable.....it fixes issue 100%
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Can someone else confirm this solution please? It's very difficult to dissamble the head unit from my car.
traxformania said:
Can someone else confirm this solution please? It's very difficult to dissamble the head unit from my car.
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Click to collapse
Did you find any solution? I have the same problem
Any updates on this? I'm experiencing the same issue when the LCD screen is bring used... Eben noting a significant difference between noise when a live wallpaper vs a plain wallpaper is being used. Would in line magnets in the power and ground source help? Any progress? This is really frustrating
Jonnymooshoo said:
Any updates on this? I'm experiencing the same issue when the LCD screen is bring used... Eben noting a significant difference between noise when a live wallpaper vs a plain wallpaper is being used. Would in line magnets in the power and ground source help? Any progress? This is really frustrating
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Not sure if it's the screen itself or the electronics on the board controlling the screen. If I ever get more time on my hands what I would love to do is try extending the ribbon cable on the screen so I could remove it away from the unit and see what that does for noise. If it works then you could always dash mount the screen and stick the unit under your seat... or what ever. Haven't had the time though.
Anyway, there have been a lot of threads and posts on noise with people trying all sorts of stuff to stop it and I haven't seen a foolproof method yet.
One thing which seems to work for those using external amps is to use the speaker level outs and convert down as opposed to using the rca outs. Another thing which seems to work is to adjust the gain on the external amp down until the noise is no longer heard. You do obviously lose a bit of volume headroom though.
I have just installed an Erisen 7591-HA (PX5) into my 2010 Golf Gti and I am getting static and digital processing sounds through my speakers.
If I mute the head unit there is no static or other sounds.
The digital processing noise happens when playing music via usb and Spotify when selecting the next track.
This is my first Android head deck and I am really disappointed.
Sound is going through an Alpine PDX-F6 amp.
I have tried disconnecting the radio plug and removing the head unit from the dash but no change still has static and processing sounds.
Sound issues remain if the engine is off it makes no difference.
Static and digital sounds do not increase with volume, it remains the same no matter what volume it is at unless the head unit is muted.
Good quality RCA and speaker cable was used.
Any help would be greatly appreciated.
I have the same issue with a Belsee unit I installed last week. Do you have a line-level filter in your harness? I have a theory that the line-level filter that's included in mine is unnecessary, as it's coming straight off where the RCA outs would normally be (and those are line level already, right?).
tonyarnold said:
I have the same issue with a Belsee unit I installed last week. Do you have a line-level filter in your harness? I have a theory that the line-level filter that's included in mine is unnecessary, as it's coming straight off where the RCA outs would normally be (and those are line level already, right?).
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Click to collapse
No I do not have a line level filter on mine.
I have tried using an RCA GROUND LOOP ISOLATOR but this done nothing.
Below is a link to the sound I am getting from the head unit, you will see it only makes the sounds when volume is not muted.
https://www.youtube.com/watch?v=0vhT7AavZbg
Same issue on my PX5 KGL unit, not tested with filters or similar...
I read somewhere that the LED color-changing caused interference - and I noticed that you have yours setup that way. Have you tried setting a static color? Also, make sure all of your wiring is clean and try to keep any speaker wires away from any power wires (although that is more applicable to an external app setup).
Can you hear the noise at all while music is actually playing? Obviously, it would be better if it wasn't there are all, but if you can't hear it normally (only hear it when nothing is playing), then I wouldn't sweat it too much. All you can do is make sure that your wiring is clean and maybe try adjusting the LED settings and the "pre-amp" settings under the factory menu (maybe see if reducing the "System" setting under "Voice" helps reduce it). Once you try using things like ground-loop isolaters, etc, then there is a chance that the music fidelity is reduced even more.
jtrosky said:
I read somewhere that the LED color-changing caused interference - and I noticed that you have yours setup that way. Have you tried setting a static color? Also, make sure all of your wiring is clean and try to keep any speaker wires away from any power wires (although that is more applicable to an external app setup).
Can you hear the noise at all while music is actually playing? Obviously, it would be better if it wasn't there are all, but if you can't hear it normally (only hear it when nothing is playing), then I wouldn't sweat it too much. All you can do is make sure that your wiring is clean and maybe try adjusting the LED settings and the "pre-amp" settings under the factory menu (maybe see if reducing the "System" setting under "Voice" helps reduce it). Once you try using things like ground-loop isolaters, etc, then there is a chance that the music fidelity is reduced even more.
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Click to collapse
Yeah have tried all the above and nothing changes.
The sound quality is poor also with higher ranges being really scratchy.
I am sure the unit would be fine if not using a higher end amp and just running the speakers off the head unit, I have read a few posts online and on youtube that the RCA output signal can be really poor with certain brands.
I just sent the unit back today for a full refund and will now be buying a brand name such as Alpine, Pioneer etc etc
https://www.hifimax.net/6-95-inch-android-7-1-quad-core-16g-auto-navigation-gps-head-unit-for-bmw-mini-2006-2013.html
Installed that unit with android 8 4gb 32gb option for a 2013 Mini Cooper Countryman S, installation went quite well, fit is great.
I knew that the factory unit was responsible of playing the vehicle chime and indicator sounds, including the blinker turn signal sounds. Before purchasing a wire harness adapter for bmw/mini that makes up for the vehicle chime/indicator sounds, I thought I'd see what solution this head unit had built in.
Unfortunately, the sounds aren't great. The unit has an external speaker that emits the sounds. The speaker is fine, but the only sound that DOES work is the blinke/turning indicator sound which is absolutely terrible. The blinker indicator tone programmed in is a recording of a classic oldschool mechanical electromagnetic relay switch tinging on and off loudly with a *twang*, lol. The length of the sound file is also too long, meaning it takes time for the sound to stop playing after the turning signal has stopped blinking. Door chimes, key/fob dinger doesn't work, vehicle information notification tone doesn't do anything. Something is strange.
The can-bus decoder seems to be built into the unit pulling from the factory wire harness that is pre-wired. I have no idea where these files are stored, if they are on a subsystem rom that's inaccessible or what but it would be very cool to be able to rewrite the audio files to work like factory. I am up to plugging in the factory unit to record all of the factory tones with some high end recording equipment I have to make it right.
Anyone have any leads of where to begin to correct this?
From my reading the CANBUS external box (which has the external speaker attached) is what is generating the sounds so unfortunately they aren't coming from the head unit itself.
millab said:
From my reading the CANBUS external box (which has the external speaker attached) is what is generating the sounds so unfortunately they aren't coming from the head unit itself.
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I don't believe that is correct as the speaker is just a 2-terminal connector plugging into the back of the LCD panel module (which houses the px5 processor module, most of the computational components. )
I have the exact same setup and am hoping for a fix...the new sounds are awful and I really miss the key and light warnings.
Hello!
I've heard that in factory settings of certain headunits there is a possibility to change Voltage of power output (stock values are too powerful for BOSE system in a lot of cars). Is this a possibility of chip itsefl (for ex. PX5/PX6) or the fact that a radio is MTCB/MTCD or not?
I'm asking because I've found relatively cheap HU on aliexpress which probably isn't MTCB/MCTD but it have PX6.
https://a.aliexpress.com/_BPTLT6
Using Optical from my Joying Android 10 unit.
Was curious about the "Power Conditioning" setting under Device - Sound - Amp
Is this basically a 'gain' setting and could this induce clipping through the Optical output?
It does increase overall volume when turning it up, so at what point does it clip, If at all?
requested to move to FYT forum
surfer63 said:
requested to move to FYT forum
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What is FYT?
Emg24538 said:
Using Optical from my Joying Android 10 unit.
Was curious about the "Power Conditioning" setting under Device - Sound - Amp
Is this basically a 'gain' setting and could this induce clipping through the Optical output?
It does increase overall volume when turning it up, so at what point does it clip, If at all?
Click to expand...
Click to collapse
On mine, the default is 50 out of a possible 60
On increasing it to 60, the sound quality was still good, but the resolution on the audio wasn't good. Volume level 1 was too loud for background and volume 0 was obviously still nothing.
Admiteddly, I'm running through a DSP and several amplifiers, so your effect might be lessened, but keeping the conditioning at 50/60 worked best for me
Emg24538 said:
What is FYT?
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There are a few real manufacturers of head units: FYT, Microntek, Topways, etc.
They deliver to resellers. For FYT those resellers are for example Medeke M300/M500/M600/K500/K600, NaviFly, Idoing, Joying, T'eyes, some Zhan units, Kingbeats, and probably a few others.
NaviFly and Medeke also sell cheaper units from other manufacturers.
jgaskell said:
On mine, the default is 50 out of a possible 60
On increasing it to 60, the sound quality was still good, but the resolution on the audio wasn't good. Volume level 1 was too loud for background and volume 0 was obviously still nothing.
Admiteddly, I'm running through a DSP and several amplifiers, so your effect might be lessened, but keeping the conditioning at 50/60 worked best for me
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Thanks for the reply!
I found a reviewer on youtube:
He did distortion tests, and said the Joying starts to clip on Optical and analog about volume level 32, and he did his testing with the "power conditioner" at 60. (I posted question about this in his comments.)
Im with you, right now I dropped it down to 50, may even go 40. I too am using a DSP to amps, and my gains are way down and its still pretty loud at low volume levels. Sounds great though.
Not sure what you mean by "volume 1 was too loud for background"?
Sorry, I meant even at volume 1, the sound was too loud even for background music, it would still drown out a conversation in the car.
Emg24538 said:
Thanks for the reply!
I found a reviewer on youtube:
He did distortion tests, and said the Joying starts to clip on Optical and analog about volume level 32, and he did his testing with the "power conditioner" at 60. (I posted question about this in his comments.)
Im with you, right now I dropped it down to 50, may even go 40. I too am using a DSP to amps, and my gains are way down and its still pretty loud at low volume levels. Sounds great though.
Not sure what you mean by "volume 1 was too loud for background"?
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I have the same unit and found no clipping at full volume on the RCAs at stock settings. This guy also tested one of the new Joying units and found the same thing, no cliping at max volume on the RCAs. He gets to the testing around 28:30
madmatt2024 said:
I have the same unit and found no clipping at full volume on the RCAs at stock settings. This guy also tested one of the new Joying units and found the same thing, no cliping at max volume on the RCAs. He gets to the testing around 28:30
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Thanks, I remember watching this video! Although he doesn't mention specifically the optical output.
But this has me curious:
Being digital, I didnt think Optical itself could induce clipping unless the data itself already had clipping in it?
So, for the headunit to control volume over Optical, I wonder...is the headunit converting digital data to analog first (DAC) then processed through its internal amplifier, to then be converted back to digital (ADC) to output through Optical? Is this how its controlling volume I wonder?
I really wish I understood how it all worked.
As far as I know, the optical output will only show clipping if the source material was recorded such that it was clipped.
The digital signal comes from the source, goes through the Android audio layer (up or down sampled, as necessary to 48Khz) and then is transformed to the correct SPDIF format (coax or optical).
In the second video (New Release Alert...) - they are just measuring the RCA outputs (so after the internal DAC), the optical/coax output is not tested.
Digital volume control is handled differently - ideally you should leave the Joying volume maxed out and control the volume downstream (i.e., through your external DSP). The Joying volume control degrades the digital signal (to degree to which it is audible is a different question) and the only way around that is to keep the Joying at full volume.