Will just Disconnecting The Front Mic Connection Fix the Issue? - MTCB Android Head Units Q&A

I just bought a JY 2.73 Double Din unit and have the poor microphone quality issue for phone calls. I've seen threads about rerouting the external microphone wiring to connect to the internal microphone wiring. I understand this is done because the internal and external microphones are thought to interfere with each other.
My question is whether we can leave the external microphone connection as is (maybe add some shielding to it) but just cut the microphone connections between the bluetooth card and the main board. Can anyone say whether this worked for them?
Thanks,
Hish

hish747 said:
I just bought a JY 2.73 Double Din unit and have the poor microphone quality issue for phone calls. I've seen threads about rerouting the external microphone wiring to connect to the internal microphone wiring. I understand this is done because the internal and external microphones are thought to interfere with each other.
My question is whether we can leave the external microphone connection as is (maybe add some shielding to it) but just cut the microphone connections between the bluetooth card and the main board. Can anyone say whether this worked for them?
Thanks,
Hish
Click to expand...
Click to collapse
Desoldering the internal mic worked well in my mtcd (as an option to remove a jumper or component was not an option) and for my mtcb, tracing the mic+ from the display board to the main board I was able to remove a jumper/zero ohm resistor. The latter is desirable as lowest noise option.

Would putting a small piece of tape on the internal mic hole not achieve the same?

Flavio said:
Would putting a small piece of tape on the internal mic hole not achieve the same?
Click to expand...
Click to collapse
No.

Related

Microphone Question

Hi,
My unit has a built in Mic, (little hole on the front).
It sounds like I'm underwater, I've seen a post about cutting capacitors which is beyond my skills.
Is it worth buying an external mic, and wiring it in, assuming there is a port at the back. Or will the result be the same as its all in the circuitry?
Thanks.
As long as you don't make the mod your mic is still going to sound bad. The external mic
is normally in parallel with the built in. One of things you do during the modification is to
separate the internal from the external, hence the removal of the capacitor/Short. Take it to a shop and modify it.
Is it the case in 100% of the KGL HUs? I have a newer Erisin HU and have no C32 on Board so I was a little bit confused if in my case both Microphones run parallelly.
halloj said:
As long as you don't make the mod your mic is still going to sound bad. The external mic
is normally in parallel with the built in. One of things you do during the modification is to
separate the internal from the external, hence the removal of the capacitor/Short. Take it to a shop and modify it.
Click to expand...
Click to collapse
ChrisKay1988 said:
Is it the case in 100% of the KGL HUs? I have a newer Erisin HU and have no C32 on Board so I was a little bit confused if in my case both Microphones run parallelly.
Click to expand...
Click to collapse
Since you didn't tell the brand I just went for the symptom. Do you have the same BT-board as in the picture
from the modification thread. It might be another SMD-component in your case. Sometimes it's a capacitor,
sometimes a 0 Ohm resistor.
halloj said:
Since you didn't tell the brand I just went for the symptom. Do you have the same BT-board as in the picture
from the modification thread. It might be another SMD-component in your case. Sometimes it's a capacitor,
sometimes a 0 Ohm resistor.
Click to expand...
Click to collapse
The Brand is Erisin ES 2698V - so a KGL unit. My BT Boards looks similar like that in the picture but differs in the C32 capacitor and in descriptions (I have no descriptions like MIC+ and so on on the Pins). The HU is actually built in my car so I cannot take a pic for you - sorry.
ChrisKay1988 said:
The Brand is Erisin ES 2698V - so a KGL unit. My BT Boards looks similar like that in the picture but differs in the C32 capacitor and in descriptions (I have no descriptions like MIC+ and so on on the Pins). The HU is actually built in my car so I cannot take a pic for you - sorry.
Click to expand...
Click to collapse
When you pull it out, beep it from the same pin as in the picture of the BT board. That way you will find
your component, being a cap, short or a = Ohm resistor.
hey,
okay I'll try it. Can you please quote the picture in this thread? I can't find it anymore
Edit: FOUND IT: http://forum.xda-developers.com/showpost.php?p=55769802&postcount=3964
halloj said:
When you pull it out, beep it from the same pin as in the picture of the BT board. That way you will find
your component, being a cap, short or a = Ohm resistor.
Click to expand...
Click to collapse
halloj said:
When you pull it out, beep it from the same pin as in the picture of the BT board. That way you will find
your component, being a cap, short or a = Ohm resistor.
Click to expand...
Click to collapse
Hey, okay I just disassembled my HU and beeped some components.
I found it finally:
It's C102! the one side beeps at Pin 4 of BT-Module, the other side beeps on microphone "SGN"
I will remove this and bridge the mic with a wire... thanks a lot!
ChrisKay1988 said:
Hey, okay I just disassembled my HU and beeped some components.
I found it finally:
It's C102! the one side beeps at Pin 4 of BT-Module, the other side beeps on microphone "SGN"
I will remove this and bridge the mic with a wire... thanks a lot!
Click to expand...
Click to collapse
Good. Write it down in the BT-thread, your HU brand and the cap-number for others to find it easy. :laugh:

External microphone in radio MTCB works or not?

I have a radio Eonon GA5155F (MTCB) with integrated microphone. I wanted to add an external microphone to improve the quality of my voice during calls. I have no problems echoing or of disturbing background noise. I would just make me feel as close and clear, approaching the quality of my voice to that during a normal call with the phone without a hands-free, because sometimes refer me to feel a little bad.
I bought a Kenwood external microphone (KCA-MC 10) and I connected at female placed on the back of the radio, but the microphone is not detected appears. I have done the test of blowing the external microphone during a call, but the receiver could not hear no noise; on the contrary if you blew on the built-in microphone on the front of the car radio bezel, the receiver feels the annoying noise of the breath on the microphone.
I tried 2 different microphones equal, therefore exclude that both are defective.
I would understand if my car radio accept a second external microphone, or my car radio has something wrong.
Or if I'm wrong type of microphone
and above all I would understand if a second microphone functioning, would function as main microphone, or in union at least built-in microphone, so as to increase the quality of my voice and make me feel stronger and clearer.
robox88 said:
I have a radio Eonon GA5155F (MTCB) with integrated microphone. I wanted to add an external microphone to improve the quality of my voice during calls. I have no problems echoing or of disturbing background noise. I would just make me feel as close and clear, approaching the quality of my voice to that during a normal call with the phone without a hands-free, because sometimes refer me to feel a little bad.
I bought a Kenwood external microphone (KCA-MC 10) and I connected at female placed on the back of the radio, but the microphone is not detected appears. I have done the test of blowing the external microphone during a call, but the receiver could not hear no noise; on the contrary if you blew on the built-in microphone on the front of the car radio bezel, the receiver feels the annoying noise of the breath on the microphone.
I tried 2 different microphones equal, therefore exclude that both are defective.
I would understand if my car radio accept a second external microphone, or my car radio has something wrong.
Or if I'm wrong type of microphone
and above all I would understand if a second microphone functioning, would function as main microphone, or in union at least built-in microphone, so as to increase the quality of my voice and make me feel stronger and clearer.
Click to expand...
Click to collapse
You must check if chassis connector is mono and your mic is stereo it might be connected wrong to the wrong channel.
I know that the microphone should be mono , since it has only one circle into the jack . But how do I control the radio ?
however, I have only one connector for the microphone on the back .
robox88 said:
I know that the microphone should be mono , since it has only one circle into the jack . But how do I control the radio ?
however, I have only one connector for the microphone on the back .
Click to expand...
Click to collapse
Try a stereo connector on your mic and test both channels.
I have tried to insert a splitter that I had at home that has the stereo connector , but nothing changes .
but I did not understand how I should " test both channels " I only have a female connector on the back of the stereo
robox88 said:
I have tried to insert a splitter that I had at home that has the stereo connector , but nothing changes .
but I did not understand how I should " test both channels " I only have a female connector on the back of the stereo
Click to expand...
Click to collapse
Use a male stereo connector push it in to the female connector unscrew the top. Use clips to test the top and than the middle
track. Ground connected all the time of course.

MTCB-HZC gets no love.

I have an XTRONS TD696A that came with Android 4.4.4. I upgraded it to 5.1, using Malaysk Roms and it operates great. Minor issues though is my DVD player no longer works. I'm not sure if it's the app that's missing, or something else. Also, i have the same MIC issues as the rest of them. I opened mine up to have a look at separating two microphones, 1 to codec, 1 to BT. But where some have C32 capacitor and C102. I seem to have a realtek chipset instead. I'm wondering if anyone had been able to do the modification on an hzc unit, and if so, where did they separate them. I will add pictures shortly. Any help on where I should be modding will be greatly appreciated, thanks!!!
*Edit* if anyone had the apk for the DVD player from the stock firmware could they please upload it, so I can see if that fixes my DVD not functioning problem.
Here are some pictures, more to come
The solder circled on the bottom right corner of the chip has continuity to the internal mic, as well as the BT mic+. It also seems to be connected to the external mic through the provided connector on the rear of the unit. The second picture is the same area just zoomed out.
NEXUS 4G said:
The solder circled on the bottom right corner of the chip has continuity to the internal mic, as well as the BT mic+. It also seems to be connected to the external mic through the provided connector on the rear of the unit. The second picture is the same area just zoomed out.
Click to expand...
Click to collapse
I have this unit and did the mic mod by breaking the connection at the BT board and soldering a new external mic jack. I can't remember where the post was that I used as a guide. It was really simple though and phone calls seem to be crystal clear.
I will try to find the post.
Goose247 said:
I have this unit and did the mic mod by breaking the connection at the BT board and soldering a new external mic jack. I can't remember where the post was that I used as a guide. It was really simple though and phone calls seem to be crystal clear.
I will try to find the post.
Click to expand...
Click to collapse
I believe you mean this post http://forum.xda-developers.com/android-auto/mtcb-hardware-development/kgl4-mic-mod-t3252424/page3
So you don't use your provided external mic Jack? How does the internal mic work for system operations?
NEXUS 4G said:
I believe you mean this post http://forum.xda-developers.com/android-auto/mtcb-hardware-development/kgl4-mic-mod-t3252424/page3
So you don't use your provided external mic Jack? How does the internal mic work for system operations?
Click to expand...
Click to collapse
Wasn't that post but it method is more or less the same. To be honest I very rarely use it for system ops so can't really comment.
Goose247 said:
Wasn't that post but it method is more or less the same. To be honest I very rarely use it for system ops so can't really comment.
Click to expand...
Click to collapse
I'll give it a shot. So you do not use the external mic connector that is provided with the unit???
NEXUS 4G said:
I'll give it a shot. So you do not use the external mic connector that is provided with the unit???
Click to expand...
Click to collapse
No, I soldered a new wire directly to the Bluetooth module and drilled a hole through the back plate for a new mic jack. I'll find the post as it had photos as well.
Goose247 said:
No, I soldered a new wire directly to the Bluetooth module and drilled a hole through the back plate for a new mic jack. I'll find the post as it had photos as well.
Click to expand...
Click to collapse
Any luck?
NEXUS 4G said:
Any luck?
Click to expand...
Click to collapse
Still trying to find it. I did find one post but the images are missing now so not sure if it was the same one.

Electrical noise?

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
dirty power maybe? did you connect a chassis ground for the 0v on the unit.. my harness came with a ground with ring terminal..
Sent from my PH-1 using Tapatalk
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.
stinger4321 said:
dirty power maybe? did you connect a chassis ground for the 0v on the unit.. my harness came with a ground with ring terminal..
Sent from my PH-1 using Tapatalk
Click to expand...
Click to collapse
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
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.
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
ADB100 said:
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
Click to expand...
Click to collapse
Try grounding the PX5 board heatsink with the unit chassis.
iRcKenny said:
Try grounding the PX5 board heatsink with the unit chassis.
Click to expand...
Click to collapse
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
ADB100 said:
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
Click to expand...
Click to collapse
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!
i have heard that the problem may be from the antenna, try getting a noise filter for the antenna
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.
ADB100 said:
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
Click to expand...
Click to collapse
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.
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.
checksum123 said:
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.
Click to expand...
Click to collapse
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.
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://forum.xda-developers.com/an...droid-8-px5-mtcelmv2-881-vw-multiple-t3884665
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.
gwaitsi said:
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://forum.xda-developers.com/an...droid-8-px5-mtcelmv2-881-vw-multiple-t3884665
Click to expand...
Click to collapse
ADB100 said:
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
Click to expand...
Click to collapse
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.
jerrymh said:
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.
Click to expand...
Click to collapse
by that token, simply turning off the wifi would prove it no?
gwaitsi said:
by that token, simply turning off the wifi would prove it no?
Click to expand...
Click to collapse
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
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).

MTCB/PX3 Background noise on calls after external mic mod

Hi,
As reported by many people the internal mic was terrible on my unit for calls. So I had the installer replace it with an external mic. However, my wife still reports that it sounds like "there is an alien on the line". I have attached a picture of the work done by the installers - is there anything else I can do to improve the call quality?
(in the photo, the external mic cord is unplugged but can be seen - it plugs into the 'socket' next to the bluetooth board. I was thinking that the external mic cord is not shielded all the way to the plug, so this may be an issue?)
The other issue I now have is I seem to have lost the ability to use voice on the unit. I can see the original mic wire has been cut, but I had assumed it would plug in to the socket near the bluetooth board anyway, so the external replacement is just moving the mic nearer to my position - if that makes sense
Thanks in advance!

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