yashsingh1/xdaforums huggingface dataset:
[MTCD Android Head Units General] ADB100:
I have a MTCD GS unit for an Audi TT and I get a feint electrical noise constantly through the cars speakers. If you have music or the radio on it is not too noticable but otherwise it is really obvious. It is definitely the unit as it isn't there with the stock head unit and if you hard reset the GS unit with the reset button whilst it is running it immediately goes away until the unit has booted. It was originally supplied with a RK3188/PX3 board running Android 5.0. I have since replaced the board with a PX5 board and have upgraded it to Android 8.0 (Malaysk). I isn't a software issue and is down to the hardware (I think...).

I have tried disabling WiFi and BlueTooth - although I don't think BlueTooth can be disabled as its not a native Android component of the system - and the noise remains. It is a feint pop and hiss noise that I think is an earth/grounding issue. I was going to replace the cable that goes to the WiFi antenna on the rear socket as this looks flimsy, however I am not sure it will make a difference.

Any ideas?

Andy
[MTCD Android Head Units General] stinger4321:
dirty power maybe? did you connect a chassis ground for the 0v on the unit.. my harness came with a ground with ring terminal..
[MTCD Android Head Units General] traxformania:
I have exactly same problem. But when the colors on LCD screen black : electrical noise increases. Any other color : electrical noise decreases. I will check groundings of unit in this weekend. I ll write here if i find out anything.
[MTCD Android Head Units General] ADB100:
It shouldn't be dirty power as it connects into the factory loom. I'll take it out at weekend and see if grounding the chassis of the head unit to the car does anything.

Andy
[MTCD Android Head Units General] xdamember2:
I had this problem on my ksp. Ultimately I found opamps under the sound processor with dirty ground on the feedback resistors. I substituted resistors to the processor board ground header lead. Now all I hear is my fan.
[MTCD Android Head Units General] ADB100:
I took the head unit out last weekend and tried earthing the chassis to the car and it made no difference - you can still hear the feint pops and hiss (all I can think to describe it is radio interference?). I also noticed that it gets worse when the cars lights are on and the head unit backlights come on (via CANBUS telling it I assume?).

It is a MTCD GS unit and has an external 'dongle' that is covered with heatshrink that is inline with the audio outputs. This has something to do with the level of the audio out - however I am just guessing here TBH.

Any other ideas how to eliminate this noise?

Cheers

Andy
[MTCD Android Head Units General] iRcKenny:
Try grounding the PX5 board heatsink with the unit chassis.
[MTCD Android Head Units General] ADB100:
I had the same noise issue when the PX3 board was installed and this has a much smaller heatsink than the PX5?

I'll give it a shot but its a bit more involved than just taking the unit out of the car though...

Andy
[MTCD Android Head Units General] iRcKenny:
So, you also have that noise before upgrading the core board, have you any chance to temporaly install another common radio like low budget Pionner, Alpine or similar? If yes check if the noise persist; some TT owners with noise from speakers said that the cause is the factory amplifier.

Have luck!
[MTCD Android Head Units General] veriluxxxx:
i have heard that the problem may be from the antenna, try getting a noise filter for the antenna
[MTCD Android Head Units General] skezza:
Record the noise with a video. Some quiet electrical noise is common, but we're talking almost silent and only when no music is playing at all.
[MTCD Android Head Units General] ab1702:
I have the same thing on my A3 and although it doesn’t really bother me I’d be interested to see if someone finds a fix. On the A3’s it only affects the ones with Bose.

All my cabling is exactly the same as yours aswell.

I once emailed a company that sells the factory Bose amps for the audis and reconditions them and the bloke said that the signal sent to the Bose amp from the aftermarket headunit is different to the signal that is sent from the factory unit so I’d guess it’s something to do with that.

In regards to the dongle thing in heatshrink, that is a little board with a plug on it that the audio cables plug into. My speakers stopped working so I cut that open once and the connector had become unplugged inside. I think it’s there because the blue amp cable is connected through it aswell which is supposed to be for the amp to turn it on and that blue cable never used to be there on the older model units.
[MTCD Android Head Units General] checksum123:
I have the same issue on my brand new dasaita 10.2 inch px5 android 8. Connected through RCA to my amp.

I will do some troubleshooting and see if I can figure it out.

BTW, there is a very loud static noise when my bluetooth is connected to my phone, I emailed dasaita about that particular issue.
[MTCD Android Head Units General] finkeo:
I have the same unit with the same issues. Hot Audio sent me a replacement bluetooth module to solder in. That fixed the bluetooth noise. I still have slight background hiss all the time.
[MTCD Android Head Units General] gwaitsi:
could you guys please take a look at my issue which includes electrical noise - even when radio is off.

e.g.

- downloading maps on Sygic, there is a clicking that goes with the increase in % of the download.

- browsing the menu and / or selecting apps has a varying noise

Interestingly, the rear-camera power seems unstable as does the GPS.

I also noted, that i couldn't power the unit on the bench via the vw quadlock connector, i had to use the white connector.

Makes me wonder if there is some general grounding problem that is the problem.

https://xdaforums.com/android-auto/...droid-8-px5-mtcelmv2-881-vw-multiple-t3884665
[MTCD Android Head Units General] An92:
I have an equal problem with my eonon px3 7.1, which is then klyde. Light rustling always constant, then when I register with the front usb camera the noise is much higher and seems a squeak of mouse .. I changed mb sent by them but the problem remains, even connecting the ground to the chassis of the car. Quache solution please guys, I'm going crazy.
[MTCD Android Head Units General] jerrymh:
I have the same isue, almost gone when changed the poor quality antenna from the WIFI (used a 9DB antenna)

Pick one from amazon,

https://www.amazon.com/gp/product/B07GDCLVPJ/ref=ppx_yo_dt_b_detailpage_o00_s01?ie=UTF8&psc=1

You can try to purchase a extension canble an antenna and put away from the unit and the engine.

In my case the pops and hiss almos gone and are barely noticiable.

The qualty of the original antenna is horrible.
[MTCD Android Head Units General] gwaitsi:
by that token, simply turning off the wifi would prove it no?
[MTCD Android Head Units General] ADB100:
You would think so wouldn't you?

I have a couple of spare SMA WiFi antennas that I can try. If I get some time later today I'll try and get the head unit out of the dash and try them. I'll post whether it makes any difference (the spare antenna I have might also be crap though...).

Andy
[MTCD Android Head Units General] ab1702:
What I found helped is that I put some ferrite beads on the power cables to the headunit and the speaker cables from the unit. It hasn’t totally removed the issue but it is certainly better and I haven’t lost any sound quality(if anything it’s slightly better as there’s less interference).
[MTCD Android Head Units General] gwaitsi:
i replaced an original RNS315 with a WinCE unit before replacing with the current PX5.

Both the WinCE and PX5 have direct Quadlock connectors like the original.

Neither of the first two units had this problem, so it was seem if shielding in the answer, it should likely be at the PCB level within the unit i.e. isolating the AMP chip from the CPU module.

at least that is what i would guess
[MTCD Android Head Units General] ADB100:
Just tried two different SMA WiFi antenna and it made absolutely no difference. This was a straight swap on the rear, so no extension cables.

Ho hum..
[MTCD Android Head Units General] gwaitsi:
i wouldn't expect it to. At least in my case, it is clear the noise is coming from the CPU/LCD and onboard RFI.

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.
[MTCD Android Head Units General] gwaitsi:
does anyone know of an app that can turn the screen off without putting the device to sleep i.e. continue playing music.

I want to test if the LCD is the source of the interference
[MTCD Android Head Units General] jerrymh:
My problem was that I had hiss and pop sounds when it is donwloading data from the internet. Seems that this PX5 units has alot of sound quality issues,

Did you tried to separate all cables or isolate the power cable from the other cables?

Or connect the unit to the car's ground?

Seems that also are people that have hiss and pops sounds when the unit is reading data from the usb ports.

Maybe the DSP units have solved this issues.

Did you tried the sound modified MCU for the unit? Some people have reduced this problem with the patched MCU.

I have reduced the blank static sound also turning down the master sound on the default settings of the unit (bt, radio, tv etc, sound is still there but reduced)
[MTCD Android Head Units General] gwaitsi:
i've updated my post #23 with much more comprehensive info.

would suggest is someone has time to remove the front panel and extend the connection cable as far as it will go,

maybe hold a piece of grounded metal sheet between the panel and the case.

Fairly confident this is from the LCD, but not sure if RFI induced, or the noise is already in the connections from the screen.

** just come to me as well, the screen has a mic in there. might pay to plug in external mic, or force switch off the mic via software if possible. **
[MTCD Android Head Units General] jerrymh:
a friend that already buy one from Dasaitia, told me that one of his speakers on his CX5 have inverted del polarity +----(-) (-)----+ on his bose amply and speakers, and he changed it, and the noise already gone.

I have noise on the front pasanger speaker, I will try later to test, but dont want to unmount al the panel to check the polarity on all speakers.
[MTCD Android Head Units General] Bo03:
There is an app in Play Store called Polarity checker. Give it a try
[MTCD Android Head Units General] jerrymh:
Donwloaded but no clue about how to use on a Car speakers, there is only 1 barr an does no thing.
[MTCD Android Head Units General] Bo03:
Click on 'read more' under the app in Play Store. There is instruction how to use it. There are three ways to do it.

---------- Post added at 12:20 AM ---------- Previous post was at 12:16 AM ----------

Basically you have to play sounds through the speakers and use your phone to test it. I think the files are included in the app. Copy them to SD card and play from the head unit or use another phone or tablet connected to your head unit.
[MTCD Android Head Units General] gwaitsi:
If the speakers have different polarities, it just means they will be out of phase. An audiophile might hear it, but most wont. At least not in a car environment.

I don't see how this will have anything to do with, what essentially is a poor design. The noise jerry describes is the same as my own. the more digital activity i.e. downloading, browsing the screen, etc generates clearly digital noise into the amp. Whether that is being induced through RFI or is inherent in the circuit i can't say. Someone with an oscilloscope could do some probing to find out.
[MTCD Android Head Units General] stormrider57:
hi there, I have some noise, with my car radio, not too pronounced, but when I connect the harness, with usb it is amplified ,and when i turn on the headlights its increase,

i found this ; IFI IDEFENDER USB ISOLATOR

https://www.amazon.com/Audio-iDefender3-0-Ground-Loop-Eliminator/dp/B01N3XKOLG

https://ifi-audio.com/products/idefender3-0/

im on mtce px5 ,kld v3.01, with a factory amp and 8 speakers an one sub ,all factory.
[MTCD Android Head Units General] CyraXXX:
Hi,

I have a Dasaita PX5 with some electrical noise. The noise is constant and clearly coming from the device itself, not the speakers. If I disconnect everything (antennas, usbs, etc..) which is possible, still there. If the brightness goes up on the device, the noise volume also goes up. It starts when I turn on the device (so before boot). What can I do? :)

Thanks!
[MTCD Android Head Units General] marchnz:
Return it.
[MTCD Android Head Units General] CyraXXX:
:D

If there is any music going on with minimum volume, I cannot hear that noise, so not that big deal. It bothers me but if I cannot resolve, than I will use it with this problem (also the seller gave me $50 refund).
[MTCD Android Head Units General] An92:
I have this issue with px3 KLD 3.01.. Dashcam usb is noise
[MTCD Android Head Units General] xandr115:
I've had my unit installed since January, 2019 and haven't noticed a problem until this past week. I've got a Daisata PX5 (I think v840) in conjunction with a Daisata Carplay adapter. At first I thought it was the carplay adapter that got wonky, but noticed the sound when I play via bluetooth and on-device youtube audio. The sound curiously goes away when I don't play audio, or when I use the AM/FM radio. More recently, I'm also noticing phone calls getting static interruption via bluetooth as well but that is hit/miss. The "electronic" whistle/hum is pretty loud and does appear to get more noticeable with volume increase. I removed the head unit yesterday to verify my ground wire didn't come loose... nothing else seems amiss and I didn't change anything except for the carplay apk (downgraded it).

You wouldn't happen to have pictures (installed) and or the size of the ferrite beads you bought? Did you isolate to only the power and speaker cables or somehow snapped the bead on the whole bundle of cables?

What email address are you guys using to contact hotaudio/daisata support? I'm communicating through the Daisata Official Store (ebay) but direct email would be preferred... so far their only recommendation is to re-flash the ha_px5_8.0_ota(20190428).zip firmware and "verify" my power and speaker harness'...
[Wing, P4350 Herald Upgrading] scostopos:
Have we found a tool to put all messages to the Storage card instead ??
[Wing, P4350 Herald Upgrading] Niwla:
I use Memmaid, and I believe memmaid can change the path where messages are stored.
[Moto G6 Plus Guides, News, & Discussion] HACK3DANDR0ID:
I just spoke to a Moto Rep face to face at a Verizon Location. I asked specificly when the G6 Plus would be available in the states and he said only 4 devices will be available in that price range, the E4, E5, G6, and G6 play.

Then in the 2 quarter they will announce the Z3 which he wouldn't comment on....

*EDIT*

I ended up purchasing a Moto G6 Plus Dual SIM International Model, because it has all the current GSM Carrier LTE Bands, but this model does not play nice on CDMA Carriers LTE, except TMOs 600mhz... Contacted Motorola in regards to turning the 600mhz band on, awaiting a reply.

Also, I contacted Moto Customer Care, they confirmed what i previously stated, in regards to NO USA G6 Plus Version.....

*EDIT*

The Moto G6 Plus Dual SIM variant will the Model # XT-1926-7 WILL BE COMPATIBLE WITH AT&T WIRELESS AND T-Mobile, except for TMO's 600mhz band, which i am waiting for an answer from the Moto Gods above...
[Moto G6 Plus Guides, News, & Discussion] HACK3DANDR0ID:
The dual Sim international version has same LTE Bands as US except 600mhz. I just ordered a G6 Plus International version from Amazon.
[Moto G6 Plus Guides, News, & Discussion] dollarpapa:
Lenovo trying to commit suicide in the US?
[Moto G6 Plus Guides, News, & Discussion] HACK3DANDR0ID:
Ordered a XT-1926-7 Dual SIM Variant of the Moto G6 Plus from Amazon, will be here tomorrow....

By the way, This particular model covers ALL GSM Carriers LTE Bands for AT&T and TMO, except for the 600 mhz band which i am waiting to find out if theres an ON switch for that...
[Moto G6 Plus Guides, News, & Discussion] Justin Hood:
Does this mean the 600mhz band only applies to T-Mobile, or would need to switch it on to use with AT&T as well?
[Moto G6 Plus Guides, News, & Discussion] HACK3DANDR0ID:
I believe the 600mhz band is more for capacity issues, and im not sure if ATT will have Roaming Agreements with TMO on said spectrum... sorry

*edit*

But the model i ordered, the XT-1926-7, covers ALL ATT and TMO current bands...only a handful of devices are running 600mhz while other models will just require an OTA update to turn 600 to the ON position.
[Moto G6 Plus Guides, News, & Discussion] Justin Hood:
edit- just saw your edit. I just looked it up, and my current US market phone is not among the handful that support that band anyway.

Thank you. I live in a remote rural area where T-mobile reception was bad, and AT&T is acceptable with a normal USA phone, so I probably do need all those bands.

Disappointed to find out no G6 plus or Nokia 7 plus in USA. Maybe that will change. In the meantime it would be great if international versions works just as well- please update if/how you get that band turned on.
[Moto G6 Plus Guides, News, & Discussion] HACK3DANDR0ID:
:DMine should be here any minute:D

My luck USPS will run late today....
[Moto G6 Plus Guides, News, & Discussion] F-L-Y-E-R:
I don't understand their sales policy, don't know about US but example from UK:

G6 Plus exclusively sold by one company not available elsewhere. Amazon UK for some reason only sells G6 Play as well says "exclusive for Amazon" but lets say Amazon DE do sell G6 Plus. P.S. Why Motorola don't sell their phones directly on their website..? I'm confused...
[Moto G6 Plus Guides, News, & Discussion] john.r.m:
Update on Activating/Enabling 600 mhz

fo use on t-mobile. Just ordered phone. Thanks
[Moto G6 Plus Guides, News, & Discussion] KC69:
If I call Moto/Lenovo direct, could I buy one for use in USA? If I told them I will be traveling abroad? Maybe?
[Moto G6 Plus Guides, News, & Discussion] JackTheMan18:
Don't believe what they say on the Amazon website about the LTE bands for the MOTO G6 Plus (XT191926-7).

They say:

HSDPA 850 / 900 / 1900 / 2100 - LTE band 1(2100), 2(1900), 3(1800), 4(1700/2100), 5(850), 7(2600), 8(900), 12(700), 13(700), 17(700), 20(800), 25(1900), 26(850), 28(700), 29(700), 30(2300), 38(2600), 41(2500), 66(1700/2100) - Dual SIM (Nano-SIM, dual stand-by)

This is not true.

The LTE bands are:

LTE band 1(2100), 3(1800), 5(850), 7(2600), 8(900), 20(800), 38(2600) - Europe

LTE band 1(2100), 3(1800), 5(850), 7(2600), 28(700) - Brazil

LTE band 1(2100), 2(1900), 3(1800), 5(850), 7(2600), 8(900), 18(800), 19(800), 26(850), 28(700), 38(2600), 40(2300), 41(2500) - India
[Moto G6 Plus Guides, News, & Discussion] john.r.m:
I returned my order using prime

After i found that same info, that there isn't a -7 variant and reported the seller.. The person who started this thread wasnt so lucky here or on the moto board..
[Moto G6 Plus Guides, News, & Discussion] Xplorer4x4:
No just but it off Amazon. I live in US and bought it from Amazon.com.

There is a XT1926-7 Variant for the G6Plus as I have it. What do you mean the OP was not so lucky?
[Moto G6 Plus Guides, News, & Discussion] john.r.m:
I used this info to inform my decision to return the g6 +

https://www.phonemore.com/motorola-moto-g6-plus/models/1819

since It doesn't list a -7 variant as the amazon ad does. If yours is a -7 variant it will be marked on the phones back bottom bezel. In the end i couldnt construct enough supportive data that persuaded me to buy the g6+. Probably the largest factor was that the G6+ didnt have a US warranty. Search for the OPs name on the G6+ motorola forum and read his lengthy exchange with them about the phones compatibility with US networks.
[Moto G6 Plus Guides, News, & Discussion] Xplorer4x4:
Stop with the misinformation.

First, you say there is no XT1926-7, now you say there is. Yes there is:

https://fccid.io/IHDT56WL5/Test-Report/XT1926-6-XT1926-7-TestRpt-DXX-3754423

Secondly, no it does not say it on the bezel. Again, take it from someone who owns the device.

Third, as for TJ/The OP, great guy. Talked to him on many occasions in the Telegram dev chat. I don't recall him having issues with carriers, but maybe I am forgetting something. We had issues with the software channel setting being RETLA not RETUS, so that might be a factor if he did indeed have issues. In either case, the device works fine for me on Straight Talk(AT&T), Simple Mobile(T-Mobile), and Walmart Family Mobile(T-Mobile). I see in the OP he mentioned CDMA carriers. The FCC report states it only supports WCDMA not CDMA. So that's probably a factor to.

If you have passed on the device, please pass up this part of the forum rather then spreading misinformation and contradicting yourself about a device you don't own which contradicts your earlier post here.