New PX6 Headunit: DSP or no DSP? - MTCD Android Head Units Q&A

Hi there. After two years on a PX5 it's time to get a new HU with a PX6 chipset. My PX5 was without a DSP but the sound was really good after updating the MCU to 3.x.
So I'm looking for this kind of device
https://www.ebay.de/itm/392478816533
This one again has no built in DSP but the price is good. A PX6 with DSP (Dasaita e. g.) is about 100 bucks higher than this. But is it worth the difference?
It's gonna ne installed on a Golf MK6 with Dynaudio.
Thanks

i bought a Xtrons PX5 without DSP module and then bought the DSP chip (my board support to add this chip) and there is a big difference with audio!

Another option is to buy a unit and install the Hal9K ROM on it (it's very easy to do, 5 minute job). It comes pre-packaged with Viper4Android (an android DSP app), which will give 95% of the inbuilt DSP functionality, plus a lot more. Hal9k is free but you need to pay a one-off fee of 10 Euro for ongoing updates. Works out a lot cheaper than the premium for a DSP unit.
I have a Dasaita with DSP, but I don't use any of the DSP functionality, I do everything in Viper instead, and to my ears, it sounds fantastic. But as a disclaimer, I have never compared a unit with DSP to one without, so I have no idea on any quantifiable differences there may be

Then u dont have a advanced car speakers/amplifiers setup. When u have amps and speakers (not factory stuff) u really NEED DSP because of the fact that u need crossover points, gaining, etc for every single speaker/rca output. All fun and stuff viper this and that. But ViperFX app cannot do this, cannot create individual channels all of the sudden. This is something that needs to be hardware built in.
Im waiting on my 2nd android headunit now in 2 month. Because i ordered one (with dsp), turns out it only has some fake ass 13band eq and a front rear shifter, no sub volume/gain control, no filtering. Besides missing allot of audio settings it sounded also like utter sh#t. The voltage out of the RCA are also way to low. So i turned it back.
Now waiting on the one with Dedicated hardware DSP. So i have individual channel audio control, real 32band eq, Filter Cutoff settings per channel (low pass, high pass). My guess is that this unit would work extremely well for my purpose and audio setup (1x 2channel amp front, 1x 2channel amp rear deck, 1x monoblock subwoofers).
Honestly i dont really get it how they cannot include subwoofer volume and hz filtering on a Android Headunit. Those are like basic audio settings in like every 1 din car radio.

AddixNL said:
Then u dont have a advanced car speakers/amplifiers setup. When u have amps and speakers (not factory stuff) u really NEED DSP because of the fact that u need crossover points, gaining, etc for every single speaker/rca output. All fun and stuff viper this and that. But ViperFX app cannot do this, cannot create individual channels all of the sudden. This is something that needs to be hardware built in.
Im waiting on my 2nd android headunit now in 2 month. Because i ordered one (with dsp), turns out it only has some fake ass 13band eq and a front rear shifter, no sub volume/gain control, no filtering. Besides missing allot of audio settings it sounded also like utter sh#t. The voltage out of the RCA are also way to low. So i turned it back.
Now waiting on the one with Dedicated hardware DSP. So i have individual channel audio control, real 32band eq, Filter Cutoff settings per channel (low pass, high pass). My guess is that this unit would work extremely well for my purpose and audio setup (1x 2channel amp front, 1x 2channel amp rear deck, 1x monoblock subwoofers).
Honestly i dont really get it how they cannot include subwoofer volume and hz filtering on a Android Headunit. Those are like basic audio settings in like every 1 din car radio.
Click to expand...
Click to collapse
Which unit have you ordered that has all of the DSP features that you describe? And if you have such an "advanced" setup, why wouldn't you use an external DSP unit for complete control?

Related

VIPER4ANDROID - Differential Sound - Great feature in your car

i do not know how many of you know about this:
Differential Sound is a feature in Viper4android - and i think many people do not know a use for it:
it can be used to correct the runtime in between your ears and your speakers in your car.
As the speaker in your car are at very different distances relative your ears (as a driver) the sound stage gets lost ...
People do buy high end stereo systems for their cars to get this feature ...
i was searching very long for this - until I found out that Viper4android does it (again - )
Try it out in your car - set the effect time to 2-5 ms and wonder about the little magic trick -
even though i use high end speakers and amp in my car - this little effect improved the sound by light years ...
(i got no connection with viper4android but am so happy with it, that i want to spread the word)
Cheers
hf
hope this can be used with a phone only connecting to Aux in of car stereo. Or is there any other way?
hainfelder said:
i do not know how many of you know about this:
Differential Sound is a feature in Viper4android - and i think many people do not know a use for it:
it can be used to correct the runtime in between your ears and your speakers in your car.
As the speaker in your car are at very different distances relative your ears (as a driver) the sound stage gets lost ...
People do buy high end stereo systems for their cars to get this feature ...
i was searching very long for this - until I found out that Viper4android does it (again - )
Try it out in your car - set the effect time to 2-5 ms and wonder about the little magic trick -
even though i use high end speakers and amp in my car - this little effect improved the sound by light years ...
(i got no connection with viper4android but am so happy with it, that i want to spread the word)
Cheers
hf
Click to expand...
Click to collapse
Yep - just connect your phone via aux-in
Sent from my GT-I9505 using XDA Free mobile app
Thanks for this my friend I have a 1200Watt Sub in my car with an amplifier and i am always looking for best settings for the in car sound
Do you have any other recommendations which i can do on Viper4Android for a better experience?
Hate to say it but I tried viper several times but was always a hassle to set it up and get it working correctly. because I change ROMs often its easier to just use poweramp and with dvc over Bluetooth enabled it also does this and evens out the speakers... Works really well.
@1qazwsx4 - yep thats one of the downsides to V4A ... sometimes its easy to install - sometimes its quite a hazzle (depending on your rom)
as i am at the moment stuck on Stock ROM: does poweramp´s dvc? works also on headphone out or only over bluetooth

MTCD SoFia "LM" Head Unit Pre-Amp Output Levels?

New to these Android units.
Does anybody here know of a way to increase the output levels from the RCA Pre-Amp Outs?
I am wondering if settings for this are in the MCU software, or in the Android side of the software. My Radio sounds great with this unit, but the Music Player app seems to have around 30, or so percent less audio volume. I have searched, but so far found very little about this issue. Any help will be much appreciated.
I ran into the same problem, so I've used a NVX LOC with independent gain controls for all 4 channels.
Thanks for your reply
Thanks, but I want to keep the factory Bose amp, because I have read in several places that the speakers in the car have a non-standard impedance that the amp is matched to. Besides that I want to keep all the wiring in the car stock so I can put everything back to stock later if wanted. There must be some way to increase the output in the units software somewhere, so I am hoping that a software guru will chime in here at some point and tell me something like: "oh, yeah, just change the values in the such and such file located in the sub folder of the System folder. I'm patient, so time will tell.
Doesn't these factory sound systems use proprietary connectors with high level inputs? I've never seen a factory amp with RCA inputs.
Proprietary Factory Audio Systems
Yes, in my case with the Infiniti Q45 it is is a proprietary system, but I used a Metra aftermarket connection adapter (Metra 70-7551) to tap the original wiring plugs that normally go into the back of the factory Bose head unit. The Metra adapter allowed me to make the connections without having to cut up the factory plugs. It included the 4 RCA plugs to tie into the original feed wiring going back to the amp in the trunk. Helped me keep everything nice and neat, and eliminated the need to run speaker wires, or make splices into the amp inputs. I also used a Metra 40-NI11 antenna adapter to convert the Nissan proprietary antenna lead to a standard antenna fitting to go into the new Android radio. I don't sell Metra stuff, but only mention it here because it helped me do a nice clean install of the new radio, and it gives me the option of going back to stock very easily.
TECHADDICT5610 said:
New to these Android units.
Does anybody here know of a way to increase the output levels from the RCA Pre-Amp Outs?
I am wondering if settings for this are in the MCU software, or in the Android side of the software. My Radio sounds great with this unit, but the Music Player app seems to have around 30, or so percent less audio volume. I have searched, but so far found very little about this issue. Any help will be much appreciated.
Click to expand...
Click to collapse
isn't that the "input gain" settings, usually reachable via factory settings?

PX5 USB Audio problems & finds discussion thread

I know that a lot of people here likes good sound quality and want to use USB DAC on their head unit.
So I started this thread so maybe someone can come up with a solution to get rid of our USB Audio problems. :good:
First of all, I have 3 different USB audio interfaces I tried on my MTCD PX5 head unit. I use these for SPDIF Coaxial output, so I can send a clean digital signal to my DSP (MiniDSP 6X8) spdif input.
My USB audio devices:
PCM2704 (Worst sound quality of the 3, but still good)
CM6631A (Nice sound quality)
SMSL x-usb (XMOS chip) (Excellent, best sound quality of my adapters)
Here is my findings for each model so far:
PCM2704 - With native Android USB Audio driver (MTCD Music player, Spotify, Google Music, etc) : Plays without any pops&clicks noises 44khz, 48Khz, 96Khz files (Thats good).. BUT only in MONO, so no stereo ! (That sucks.)
PCM2704 - With custom USB Audio driver (Usb Audio Player Pro, Neutron, Hibby, Onkyo apps) : Plays perfectly 44khz audio files but CANNOT play 48khz or 96khz audio files, there is no sound. at all :crying:
CM6631A - With native Android USB Audio driver (MTCD Music player, Spotify, Google Music, etc) : Lots of pops&clicks noises, cannot listen to this.. BUT output in stereo, plays 44khz/48khz/96khz files.
CM6631A - With custom USB Audio driver (Usb Audio Player Pro, Neutron, Hibby, Onkyo apps) : Lots of pops&clicks noises, cannot listen to this.. Output in stereo, plays 44khz/48khz/96khz.
SMSL X-USB Xmos - With native Android USB Audio driver (MTCD Music player, Spotify, Google Music, etc) : Lots of pops&clicks noises, cannot listen to this.. BUT output in stereo, plays 44khz/48khz/96khz files.
SMSL X-USB Xmos - With custom USB Audio driver (Usb Audio Player Pro, Neutron, Hibby, Onkyo apps) : Lots of pops&clicks noises, cannot listen to this.. Output in stereo, plays 44khz/48khz/96khz.
Good to know:
PCM2704 is USB 1.1 full speed device, isosynchronous.
CM6631A is USB 2.0 fullspeed/high speed device, asynchronous.
SMSL X-usb Xmos is USB 2.0 fullspeed/high speed device, asynchronous.
Also good to know: Android Marshmallow 6 Mono output USB Audio problem is a well known problem across multiple Android devices (Cellphones, tablets, etc.) So lets assume the mono output on the PCM2704 is "normal". What is not normal with the PCM2704 is that it can only play 44khz audio, no 48khz.
First question that comes to my mind: Does the PX5 USB drivers/kernel has a problem with USB2.0 ?
Another question: Does our PX5 firmware mess with the sample frequency (44khz, 48khz, etc) ?
Thanks for any useful comment !
I can't believe I'm the only one here using a USB DAC on a PX5..?
I also interested
Sent from my MI MAX 2 using Tapatalk
---------- Post added at 01:17 PM ---------- Previous post was at 01:15 PM ----------
How to get the px5 use usb as digital out? I tried cyrus soundkey but no sound
Sent from my MI MAX 2 using Tapatalk
excellent thread, I was just trying to search on this very thing. My guess that using this as audio output it does not pass the radio or AVIN through it does it? since the MCU is separate from android
I have heard (but not tested first hand) that these will play stereo on 6.0.1
HiFimeDIY Sabre 2016
SA9227 + PCM5102A ( on eBay, http://www.ebay.com/itm/182289773453?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT)
M2Tech HiFace DAC
FiiO Q1
-=Jeff=- said:
excellent thread, I was just trying to search on this very thing. My guess that using this as audio output it does not pass the radio or AVIN through it does it? since the MCU is separate from android
I have heard (but not tested first hand) that these will play stereo on 6.0.1
HiFimeDIY Sabre 2016
SA9227 + PCM5102A ( on eBay, http://www.ebay.com/itm/182289773453?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT)
M2Tech HiFace DAC
FiiO Q1
Click to expand...
Click to collapse
If I test my 3 USB audio devices with USB Audio Player Pro, they all work great on my Android 6 Lenovo Tablet, Nexus 6P cellphone (Android 7/ Android 8 Beta), and worked perfectly on my previous PX3 (RK3188) (Android 5.1) Head unit.
So I dont think it's a compatbility problem with the Android version, it's more of a software/kernel issue, the way the audio is handled with the PX5.
I tried changing some settings in audio_policy.cfg but I did not manage to stop the pops/clicks from happening.
Hi,
I am also very interested in using USB Audio on a PX5.
I have an EONON GA7150A 32GB BMW unit.
MCU is "MTCD_WWW_V2.54b_2", Build is "px5-userdebug 6.0.1 MXC89l user.hct.20170617.171922 test-keys"
I run a car audio / performance / engineering company. We're doing a SQ install on a 04 BMW M3 with all Audison Prima gear going to an Audison Bit 8.9 amp/processor.
I got a Behringer UCA-222 hoping to use it - plugging it into my tablet (Samsung Tab S 8.4") - it works perfectly without any configuration, so I had hoped it'd work with the Android HU as well.
Plugging it into the Android HU - it DOES work - I can play audio from any apps (YouTube, Google Voice Search both output to the USB device) - I have installed SoundAbout Pro to try and re-route all audio to the USB DAC but it doesn't work for everything.
My issues are:
- The FM radio plays through the internal pre-amp/amplifier.
- The volume control (whether through the touchscreen on the menu, or using the hardware knob) does not affect the USB device - there is no way to change it's volume from the head unit this far.
I'm ready/willing to flash/hack this unit as best I can, can't brick it as it belongs to a client (fingers crossed) but I definitely want to use the USB DAC full-time.
If I could find a way to loop the RCA inputs to the optical output on the UCA222 (maybe a custom app) that would be enough to route the radio output through the optical but that's definitely not ideal.
There has to be other people wanting/needing to do this! These units DACs leave a lot to be desired (I'm being nice) and there's a huge selection of great USB DACs.. Heck, in my configuration I won't even be using the DAC in the Behringer - it'll be all digital until it hits the Audison processor/amp with it's internal DAC feeding it's internal amp and a pre-amp that outputs to the separate sub-woofer amplifier (AP1D).
I have the deck setup on my desk right now hooked to a power supply and booted, on WiFi and ready for hacking. What can we do?
From what I've read the MCU controls all the hardware buttons - though I'm not sure it'll be required to mess with it..?
How does Android see the internal audio chip? I know the MCU communicates with it over SDIO, does android as well? I guess no as I read another thread that has a hack/app allowing more control over the audio chip by interfacing one the SoCs GPIO/SDIOs to the chip.
So, how does the radio app work then? Does it just send a signal telling the radio chip to route its audio to the audio chip? Or does Android actually see some sort of audio device for the radio? If it just tells the audio chip which "source" to use and the radio chip outputs directly to it, I'm not sure there's going to be a way to get radio over digital without a converter box to convert that analog output to digital..
All other Android outputs shouldn't be a problem, from what I can tell everything else is already playing over USB for me.. except the radio and volume control.. even the "beeps" you hear when adjusting the volume come over the internal audio device not USB..but Google Voice Search and YouTube work over USB fine..
---------- Post added at 03:05 AM ---------- Previous post was at 03:04 AM ----------
I find it odd that your seeing pops/clicks.. I have had no issues and fully stable audio from the apps it does work from.
forbiddenera said:
Hi,
I am also very interested in using USB Audio on a PX5.
I have an EONON GA7150A 32GB BMW unit.
MCU is "MTCD_WWW_V2.54b_2", Build is "px5-userdebug 6.0.1 MXC89l user.hct.20170617.171922 test-keys"
I run a car audio / performance / engineering company. We're doing a SQ install on a 04 BMW M3 with all Audison Prima gear going to an Audison Bit 8.9 amp/processor.
I got a Behringer UCA-222 hoping to use it - plugging it into my tablet (Samsung Tab S 8.4") - it works perfectly without any configuration, so I had hoped it'd work with the Android HU as well.
Plugging it into the Android HU - it DOES work - I can play audio from any apps (YouTube, Google Voice Search both output to the USB device) - I have installed SoundAbout Pro to try and re-route all audio to the USB DAC but it doesn't work for everything.
My issues are:
- The FM radio plays through the internal pre-amp/amplifier.
- The volume control (whether through the touchscreen on the menu, or using the hardware knob) does not affect the USB device - there is no way to change it's volume from the head unit this far.
I'm ready/willing to flash/hack this unit as best I can, can't brick it as it belongs to a client (fingers crossed) but I definitely want to use the USB DAC full-time.
If I could find a way to loop the RCA inputs to the optical output on the UCA222 (maybe a custom app) that would be enough to route the radio output through the optical but that's definitely not ideal.
There has to be other people wanting/needing to do this! These units DACs leave a lot to be desired (I'm being nice) and there's a huge selection of great USB DACs.. Heck, in my configuration I won't even be using the DAC in the Behringer - it'll be all digital until it hits the Audison processor/amp with it's internal DAC feeding it's internal amp and a pre-amp that outputs to the separate sub-woofer amplifier (AP1D).
I have the deck setup on my desk right now hooked to a power supply and booted, on WiFi and ready for hacking. What can we do?
From what I've read the MCU controls all the hardware buttons - though I'm not sure it'll be required to mess with it..?
How does Android see the internal audio chip? I know the MCU communicates with it over SDIO, does android as well? I guess no as I read another thread that has a hack/app allowing more control over the audio chip by interfacing one the SoCs GPIO/SDIOs to the chip.
So, how does the radio app work then? Does it just send a signal telling the radio chip to route its audio to the audio chip? Or does Android actually see some sort of audio device for the radio? If it just tells the audio chip which "source" to use and the radio chip outputs directly to it, I'm not sure there's going to be a way to get radio over digital without a converter box to convert that analog output to digital..
All other Android outputs shouldn't be a problem, from what I can tell everything else is already playing over USB for me.. except the radio and volume control.. even the "beeps" you hear when adjusting the volume come over the internal audio device not USB..but Google Voice Search and YouTube work over USB fine..
---------- Post added at 03:05 AM ---------- Previous post was at 03:04 AM ----------
I find it odd that your seeing pops/clicks.. I have had no issues and fully stable audio from the apps it does work from.
Click to expand...
Click to collapse
That's cool. I suppose you're member of Strictly Sound Quality group on Facebook ?
I'm really into SQ as well, Pioneer Premier / Hivi amps, MiniDSP C-DSP 6X8, Wavecor/Peerless 3 way active.
Anyways, back on topic: You say your Behringer UCA-222 outputs music without problem with regular players, but does it play in stereo ? Because my PCM2704 also plays audio nice without any click/pops noises but it output both channel mono, so no stereo effect, every sounds plays on both Left and Right. Sounds pretty dull for a SQ setup, it stages like poop lol. I only get stereo out of my PCM2704 if I play it through USB Audio Player Pro app, because that app uses his own USB audio driver.
For you FM Radio routing problem, is there I way to sum input channels on your DSP ? IE: With my MiniDSP I can play both SPDIF and RCA Inputs at the same time on specified output channels.
Thanks for your participation btw. :good:
Thought about getting a minidsp but the beringer was available locally and as I'm actually not using the DAC within it, I didn't care.
The 222 does have a monitor switch which sums all inputs to the 1/8 headphone jack but not over optical.
I could potentially write a small background app to sum the rca input on it to the output constantly but still have the volume control problem.
Video of interface.. I'll make a demo on how the USB audio actually works shortly, I'll install a frequency generator app so I can test stereo for you.
Happy New Year guys!
1. All Rockchips headunits (rk3066/3188/3288/px3/px5) have a big problem with their DWC-OTG USB 2.0 controller kernel driver from Designware/Synopsys.
This driver generates a huge amount of interrupts on usb bus (about 15000 per second under load and 8000 minimum without any use of usb devices). So any wide streaming devices like USB-DACs, USB-CAM, EasyCAP and others cannot properly function. USB-DACs on samplerates higher 44100 or 48000 Hz and bit depth higher 16 bit generate many pop and clicks in sound or just noise. All usb streams are very slow, even copying files from usb flesh to sd card.
This problem is well known and it has the resolution - kernel driver needs to be patched.
Here are some links:
http://hwswbits.blogspot.ru/2013/09/dwc-usb-interrupt-spam-in-rockchip-socs.html?m=1
https://www.google.ru/amp/s/ideechaniz.wordpress.com/2014/02/26/dwc-otg-drivers/amp/
We have not kernel sources to patch it. Any open sources will not go because of many special functions of our HUs have been compiled into kernel. I wrote about this to SHEN ZHEN KLYDE ELECTRONICS CO twice, but no reaction (I have their HU).
So you cannot play sound higher then 16 bit 44100Hz or 48000Hz. If you try 24 bit and/or 96kHz you can hear clicks and pops or just a noise. The first step to make the situation better is to get usb-dac/converter with only FULL-speed (12Mb/s) usb-reciever chip, like sa9023, te7022, pcm2704(6) (mono!) etc. Unplug all usb devices except usb-dac from usb. Note that wifi and processor's loads affect too. Edit /etc/audio_policy.conf to limit sr and bd to 44100 and 16 for usb_device section. If you want to use your high speed usb-dac you can try to find and use a full speed usb hub on ali or ebay.
2. All android HUs for now have mcu and android boards inside. All apps like youtube, navigation, poweramp etc are sounding from android board and all of them can be routed to play through usb-dac using usb audio function of android. But dvd, bt hands-free, radio are located on and managed by mcu board. So sound from them does not going to/through android board. The only one way to get their sound on your car audio processor is connection of rca-outs and set processor to auto switch between analog and digital inputs by signal determination (helix dsp and many others can do that).
3. The volume. The best way for SQ is to use the dsp's volume adjustment. Note for digital volume adjustment every -6bB from max level excludes 1 bit from effective bit depth. So you loose your sound quality (dynamic range) by digital volume adjusting on HU because you can only have 16bit output (see 1). But if you WANT to do it there is one difficult way - write your own app service to catch mcu's broadcast commands for volume adjusting and then send alsamixer's comnands to change usb dac volume same level (need to install alsa). I made it for rk3066/rk3188 HUs on petrows microntec headunit service. Hope this help https://github.com/petrows/RK3066-Headunit-service
https://www.google.ru/url?sa=t&sour...MQ5YQBCCcwAA&usg=AOvVaw2W8hsXylKrMeQRC2R2mOVt
This service also can send buttons presses to Poweramp, USB Audio Player Pro, Spotify, PCRadio etc. But it is for MTCB, not for MTCD HUs. I dont know a difference of Microntek services of this versions of HUs. So I cannot say will it work or not on MTCD.
Question which has better sound?
Chich output > dsp > amp or
Usb dac > amp
??? I think the sound should just be good with a dsp or im wrong?
aluver said:
All apps like youtube, navigation, poweramp etc are sounding from android board and all of them can be routed to play through usb-dac using usb audio function of android.
Click to expand...
Click to collapse
Thanks man for the detailed post.
How do i do this. Is it in the developer options where we select to use Audio source for USB . What would happen in case we have multiple USB devices in use?
Thanks in advance.
kaderekusen said:
Question which has better sound?
Chich output > dsp > amp or
Usb dac > amp
??? I think the sound should just be good with a dsp or im wrong?
Click to expand...
Click to collapse
What do you mean under "Chich output". RCA? I think dsp cannot make the sound of HU's RCA better. It has a very poor quality with low voltage - so you get a lot of noise and "unsharped" sound.
---------- Post added at 11:39 AM ---------- Previous post was at 11:29 AM ----------
piyush7243 said:
Thanks man for the detailed post.
How do i do this. Is it in the developer options where we select to use Audio source for USB . What would happen in case we have multiple USB devices in use?
Thanks in advance.
Click to expand...
Click to collapse
I don't think dev options have it. I think usb audio must work from the box on android 6 firmware, but it may depends from firmware version. To dermine usb audio driver exist in kernel just plug in your usb-dac and view file /proc/asound/cards - it will show you all plugged sound devices for this moment. But note at first you need to entirely stop all installed direct players like UAPP, Hybi, NeutronMP etc.
aluver said:
[/COLOR]I don't think dev options have it. I think usb audio must work from the box on android 6 firmware, but it may depends from firmware version. To dermine usb audio driver exist in kernel just plug in your usb-dac and view file /proc/asound/cards - it will show you all plugged sound devices for this moment. But note at first you need to entirely stop all installed direct players like UAPP, Hybi, NeutronMP etc.
Click to expand...
Click to collapse
Dev options have it and i have enabled it there as well. but not sure on which USB port. Also currently i am at the highest firmware level and ROM level. No 3rd party USB driver is installed, still cant get the USB audio out. I have even replaced the audio_policy.conf.
I will check if the device is getting detected or not
piyush7243 said:
Dev options have it and i have enabled it there as well. but not sure on which USB port.
Click to expand...
Click to collapse
Good info. Is your firmware from enthusiasts or from a producer?
You have to use USB port for 3g-modem - it must be otg. But on my Klyde rk3066 mtcb hu I have all 3 usb ports working with dac.
audio_policy.conf must be in /etc for proper usb audio functionality.
Didn't understand about usb modem. I use 2 HDD and a USB DAC .the firmware is Hotaudio Dasaita default one. Do you have the audio_policy.conf file for my reference
Sent from my Pixel 2 XL using Tapatalk
I mean otg usb port is usually marked "3g-modem" or like that.
audio_policy.conf may be different for our HUs. Besides, I have android 4.4.4 rom. But I attach my 2 versions of audio_policy.conf. The second version is from ROM that contains a file /system/lib/hw/audio.alsa_usb.rk30board.so. So policy contains alsa_usb section.
What is your result with driver?
aluver said:
I mean otg usb port is usually marked "3g-modem" or like that.
audio_policy.conf may be different for our HUs. Besides, I have android 4.4.4 rom. But I attach my 2 versions of audio_policy.conf. The second version is from ROM that contains a file /system/lib/hw/audio.alsa_usb.rk30board.so. So policy contains alsa_usb section.
What is your result with driver?
Click to expand...
Click to collapse
Thanks for putting this here. Btw nothing was marked on my USB cables so swapping usb helped and one of them worked on apps.
Now another quick question. Tried Poweramp but it didn't see the usb DAC. Jet audio would hang. Any other music apps which doesn't use its proprietary driver.
I can use UAPP but it seems that it locks the usb DAC and doesn't allow the other apps to have access.
With UAPP it says usb device initialised but yesterday no such message.
Sent from my Pixel 2 XL using Tapatalk
piyush7243 said:
Now another quick question. Tried Poweramp but it didn't see the usb DAC. Jet audio would hang. Any other music apps which doesn't use its proprietary driver.
Click to expand...
Click to collapse
Did you use Poweramp v3 alpha? What version? Better use v703 for your android 6. What samplerate do you have in audio_policy.conf at usb_device section now? Need to limit it 44100 and 16 bit depth. Poweramp 3 may not work with usb-dac directly in case of many software and hardware combinations reasons. But you can use Poweramp v2 - it may work as other apps through android kernel usb audio driver.
---------- Post added at 08:44 AM ---------- Previous post was at 08:29 AM ----------
piyush7243 said:
I can use UAPP but it seems that it locks the usb DAC and doesn't allow the other apps to have access.
With UAPP it says usb device initialised but yesterday no such message.
Click to expand...
Click to collapse
I wrote earlier about this. All direct players always lock usb-dac. I am not sure but seems to be Poweramp v3 alpha does not lock dacs, internal at least. Try it.
I am back , after the reboot, the usb DAC is not being used again. Ughhhh. Need to break my head more to get to bottom of this behaviour.
Sent from my Pixel 2 XL using Tapatalk

What is a 'WWW' MCU? Anyone using USB Audio?

Hi,
I run a car audio firm, we have a PX5-based unit a client ordered.. The MCU version is "MTCD_WWW_V2.54b_2" .. Our goal is USB audio working proper, among a few other things (better interface if possible, better apps, better SQ stuff)
I haven't seen a "www" mcu anywhere? It's sold as an EONON GA7150A..
Anyone know anything about this MCU? If it's compatible with any others or anything like that? I definitely would like to root it, update the ROM to something better, get rid of the "Windows Mobile" part of it which was, IIRC, advertised as the ability to 'boot' between Android and Windows but is actually just a different interface theme from the home screen.. Also want to do whatever we can for sound quality and smooth experience.
I should note that, as a car audio company (in Canada), we are seriously considering producing our own Android units.. likely 'producing' would consist of getting units like a px5, branding them and primarily, having a SOLID software system built for automotive use. I think a lot of these units are a great start and are ALMOST there for a lot of things but..some of the interface stuff is rushed, not translated great, etc.
What I'd like to see is an Android unit, priced like these ones usually are, but with *really* good class A interfaces. The kind of experience you'd expect on a Samsung phone or a Pioneer headunit. I personally have been using my Samsung Tab S 8.4" in my car as my 'head unit' (paired with a Pioneer single din for a hardware volume knob and some easy control) for along time and I would not want to ever go back.
Here's a short video of the interface and version info..
My eventual goal is getting USB audio working decently. It does work for most Android apps but the volume control only controls the internal audio chip, and the radio app routes through the internal audio chip as well.. I assume perhaps other sources like DVD and line-in would as well, I haven't verified but I will pretty quick here. I plan on making another video showing what works/what doesn't/how it works.
I'm hoping for a software only solution but am happy to hack the hardware if needed. I'm using a Behringer UCA-222 as a "DAC" (same as 202 but red in color) but won't actually be using the DAC in it but only it's optical output into an Audison Bit 8.9 DSP/Amplifier.
There's the possibility of routing the px5's audio output RCA's to the Behringer's Input and 'monitoring' that input to the optical output via software but that doesn't solve the fact the volume control does nothing for apps when using the USB.. Eg, youtube plays through USB/optical fine but volume control doesn't change the volume..Radio plays through the px5's audio chip and volume control controls that, and shows on screen.. I could force everything to play thru the px5 audio chip and then monitor it to optical but that defeats the purpose of what I'm trying to do completely (full digital audio to the amplifier).
I'm willing to sacrifice some sources re-routed like that though, eg, the radio would be fine as it already sounds ****. Aux in also doesn't sound great usually and won't be used in this car anyway. DVD would be nice to have optical out as well but
I'm currently still searching for a schematic/block diagram for these devices, this would probably answer a lot of my questions like.. I'm curious whether audio from any of the other onboard devices (radio, dvd, aux in) go through Android at all or whether they're directly sourced to the output chip.
If it's the latter - that sucks - but I wouldn't be surprised. I have read the thread about the hardware hack to allow android control of the audio chip but I don't see this giving me the functionality I need. If it is wired like this, and I can get the other components (eg. radio chip) to output their audio to Android, digitally somehow and have Android push it to the USB audio device that'd be cool.
Is no one else using a USB dac on any of these units? I have many years experience coding, hacking, electronic engineering, tinkering, etc. including Android but I haven't done many of these Android Head Units.. A lot of times we use tablets instead! But this client wanted OEM look..so we thought we'd give it a shot.
The difference between the audio quality from the internal DAC and the USB audio device's optical routed directly to the DSP (digital to the power amp) is definitely noticeable, even with there being very little noise picked up in our interconnects.
Hi,
I can help you only with WWW MCU,
forbiddenera said:
Hi,
I run a car audio firm, we have a PX5-based unit a client ordered.. The MCU version is "MTCD_WWW_V2.54b_2" .. Our goal is USB audio working proper, among a few other things (better interface if possible, better apps, better SQ stuff)
I haven't seen a "www" mcu anywhere? It's sold as an EONON GA7150A..
Anyone know anything about this MCU? If it's compatible with any others or anything like that? I definitely would like to root it, update the ROM to something better, get rid of the "Windows Mobile" part of it which was, IIRC, advertised as the ability to 'boot' between Android and Windows but is actually just a different interface theme from the home screen.. Also want to do whatever we can for sound quality and smooth experience.
Click to expand...
Click to collapse
tha same question (#1956) i read in this thread https://forum.xda-developers.com/an...-head-unit-discussion-thread-t3573881/page196
it should be KLD (klyde), you can read the answer in post #1959
Thanks for the pointer.
Hi,
I uses the newsmy carpad since 2 yrs with android box with wince interface and same issue of radio, bt and dvd being analog while the android side of things is 100% digital output via the included hdmi.
I put aside my alpine pxa-h900 and installed the helix dsp pro with auto switching of input with priority on digital input and use internet radio apps, android bt apps and plugged in an usb portable drive for dvd/cd.
Cheers.
Richard
Singapore

Apple USB-C to 3.5mm DAC dongle and Android - remove the power limit

So I finally got fed up enough to purchase a USB-C DAC dongle to overcome the unbearable hissing noise of the inbuilt 3.5mm audio jack. The first obvious choice would be a Pixel dongle, but for some reason Apple is selling a better performing dongle. Being cheaper and available in a mortar store, it was a no brainer purchase. I can definitely say that hissing is gone and sound is crystal clear. However for yet another reason, Apple dongle is by default quite limited in power, being usable mainly by sensitive IEMs. After several attempts of various methods, I found a reliable way of removing this limit.
Ingredients needed:
1. Apple DAC dongle
2. Tasker
3. Magisk
4. AlsaMixer app (https://apkpure.com/alsamixer-root/com.skvalex.alsamixer)
Recipe:
1. Extract AlsaMixer app and locate "assets\alsa\system" folder
2. Create a Magisk module from this folder with 755/755 rights
3. Install Magisk module
4. Create a Tasker event "headphones connected", task "shell script", run as root, command "alsa_amixer -c 1 sset Headphone 120"
5. Connect Apple dongle
Voila, you suddenly moved from -40dB limit to 0db for max volume. Limit is automatically reset on each DAC re-connection, so Tasker intent is mandatory.
Verification:
1. In terminal write as root "alsa_amixer -c 1" to see the current playback limit. It obviously works only with DAC connected.
Note: this method works only for USB-C DACs, not for analog audio jack of Mi A1 phone.
Default:
Code:
# [B]alsa_amixer -c 1[/B]
Simple mixer control 'Headphone',0
Capabilities: pvolume pswitch pswitch-joined penum
Playback channels: Front Left - Front Right
Limits: Playback 0 - 120
Mono:
Front Left:[B] Playback 80 [67%] [-40.00dB][/B] [on]
Front Right:[B] Playback 80 [67%] [-40.00dB][/B] [on]
Headphones with no mic:
Code:
# [B]alsa_amixer -c 1 sset Headphone 120[/B]
Simple mixer control 'Headphone',0
Capabilities: pvolume pswitch pswitch-joined penum
Playback channels: Front Left - Front Right
Limits: Playback 0 - 120
Mono:
Front Left: [B]Playback 120 [100%] [0.00dB][/B] [on]
Front Right: [B]Playback 120 [100%] [0.00dB][/B] [on]
Headset with a mic:
Code:
# [B]alsa_amixer -c 1 sset Headset,1 120[/B]
Simple mixer control 'Headset',1
Capabilities: pvolume pswitch pswitch-joined penum
Playback channels: Front Left - Front Right
Limits: Playback 0 - 120
Mono:
Front Left: [B]Playback 120 [100%] [0.00dB][/B] [on]
Front Right: [B]Playback 120 [100%] [0.00dB][/B] [on]
--first post updated--
Why don't you use tinymix, that is included on any Android release, instead of alsa_mixer so that you don't need to install other stuff?
drizzt said:
Why don't you use tinymix, that is included on any Android release, instead of alsa_mixer so that you don't need to install other stuff?
Click to expand...
Click to collapse
Wasn't aware of this fact, thanks. Will check tinymix, but alsa seems to be much easier to use for this purpose (at least for me ).
Edit:tinymix is just too complex to use and control commands probably aren't 100% universal with all DACs, so I'll stay with ALSA and Tasker. If I wanted to utilize tinymix, I'd just use this app (Apple dongle requires special version) https://forum.xda-developers.com/pixel-2-xl/themes/pixel-2-usb-audio-control-t3704024
Hissing sound? Bro have you checked the internals of your phone? I did and I had a snake inside, after getting him out everything was fine
Yes, I have a very inteligent snake in there, which hisses only when I connect headphones and only during music playback + about 3 seconds once it stops. Also the snake is able to distinguish between sensitive low impedance IEMs and less sensitive bigger headphones, so it adjusts volume of its hissing accordingly. What's even more interesting, he keeps quiet when I connect an external DAC. I want to keep the snake, so I won't remove it from the phone.
Well, it's that or there's ****ty audio output circuit in the phone.
Fixes the PH-1 !
I came across your thread while looking for a fix for the Apple dongle when used with the Essential PH-1. The problem is when using a TRS headset with this specific dongle+phone combo the left and right channels are at significantly different volumes. A TRRS headset does not exhibit this issue.
TRRS reports Headset,1
TRS reports PCM,0
I renamed xbin to bin. Not sure if that is the right solution, but the tools were not showing up before. A quick Tasker task and it's all set!
Thank you so much!!
numanair said:
I came across your thread while looking for a fix for the Apple dongle when used with the Essential PH-1. The problem is when using a TRS headset with this specific dongle+phone combo the left and right channels are at significantly different volumes. A TRRS headset does not exhibit this issue.
TRRS reports Headset,1
TRS reports PCM,0
I renamed xbin to bin. Not sure if that is the right solution, but the tools were not showing up before. A quick Tasker task and it's all set!
Thank you so much!!
Click to expand...
Click to collapse
Thanks for letting us know and I'm glad this guide helped you. Different phones can have different bin folder and also parameters for alsa-mixer, so you did the right thing.
Works on Oneplus 7 pro (Android 10). Just had to change "Headphone" to "Headset" in the alsa_amixer command.
Been trying to get a magisk module made for this on my Razer Phone 2 and it took me quite a while since I kept getting errors. I got fed up and decided to try Samsung's dongle since that surely would've been optimized for Androids, but it seems that it also had the same exact issue (go figure, Samsung practically copied Apple 100%). The Samsung dongle is the same quality as Apple's dongle for sound quality (albeit a tiny bit worse, practically unnoticeable) and also, the same volume output from the same set of earbuds at max. So back to figuring out the whole magisk module thing.
Anyways I got the issue resolved. I remade the module I had on my pc rather than doing it on the phone itself and the error magically went away, and the whole thing is working wonderfully now. Even works for the Samsung USB-C 3.5mm dongle, with a different value. 108 for the Samsung dongle rather than Apple's 120.
Thank you for posting the guide, super helpful to fix this issue for the Apple and Samsung dongles on Android in general.
Thanks for this thread. Could I use this stuff to fix my AirPods Pro with my OnePlus 7 Pro? I have to set the volume to max to hear something in the bus ;-;
cedricberger27 said:
Thanks for this thread. Could I use this stuff to fix my AirPods Pro with my OnePlus 7 Pro? I have to set the volume to max to hear something in the bus ;-;
Click to expand...
Click to collapse
I'm afraid that it's not possible to control external amplifier connected over bluetooth (or at least I don't know about any way how to do it). USB-C dongle can be configured because Android sees it connected "internally" as a sound card. AirPods and similar have DAC ("sound card") in the earphones and phone can use only standard Bluetooth commands to send music and perform basic control. AFAIK, changing the gain parameters isn't among them.
kenvenin said:
Works on Oneplus 7 pro (Android 10). Just had to change "Headphone" to "Headset" in the alsa_amixer command.
Click to expand...
Click to collapse
brother, i tried to make the module for my OnePlus 6 but can't get it to work. it will be great help if you please share your magisk module. thanks in advanced
Can someone upload this module here? Or maybe give some tutorial how to make a magisk module? I was searching for this, but I didn't find it.
Adamz274 said:
Can someone upload this module here? Or maybe give some tutorial how to make a magisk module? I was searching for this, but I didn't find it.
Click to expand...
Click to collapse
Not sure if it's still working (I created and installed this module while on Magisk v19 and modules format changed since then), you might need to update "META-INF\com\google\android\update-binary" script with the latest version from here https://topjohnwu.github.io/Magisk/guides.html (and maybe remove "install.sh")
EU/USA Model
_mysiak_ said:
Not sure if it's still working (I created and installed this module while on Magisk v19 and modules format changed since then), you might need to update "META-INF\com\google\android\update-binary" script with the latest version from here https://topjohnwu.github.io/Magisk/guides.html (and maybe remove "install.sh")
Click to expand...
Click to collapse
Maybe I misunderstood but from everything I have read, the EU version of the Apple Adapter is worse, much quieter. I thought that was in the hardware, the US version is full power.
'There are 2 versions of it, US version A2049 which could output 1v, and EU version A2155 which limited to 0.5v' from another source
https://www.reddit.com/r/headphones/comments/ecf1ud/apple_usbc_to_35mm_adapter_impressions/
Is this 'fix' able to achieve the full 1v power output on the EU Model ?
poster74 said:
Maybe I misunderstood but from everything I have read, the EU version of the Apple Adapter is worse, much quieter. I thought that was in the hardware, the US version is full power.
'There are 2 versions of it, US version A2049 which could output 1v, and EU version A2155 which limited to 0.5v' from another source
https://www.reddit.com/r/headphones/comments/ecf1ud/apple_usbc_to_35mm_adapter_impressions/
Is this 'fix' able to achieve the full 1v power output on the EU Model ?
Click to expand...
Click to collapse
As far as I know it's SW limitation, affecting mostly Android phones (not sure about Apple devices, I don't own any). My phone and dongle come from the official EU distribution, so I assume that it's the EU version. The fix definitely removes the power limit. I do not have an US dongle (or measurement device), so can't compare them though. All I can say for sure it's that with sensitive IEMs the dongle is dead silent, there is no hissing noise. At the same time, and after removing the power limit, the dongle can drive AKG K240MK2 (55ohms) cans without problems. It struggles a bit with Beyerdynamic DT990pro (250ohm) - depending on the sound source, volume can (Google music) or won't be enough (most Youtube videos).
Hi,
I appreciate you dont have meter to measure output but are you saying that this fix seems to increase the volume limit significantly ? The US version is supposed 1v against EU 0.5V.
Does this fix, 'feel' that much louder ?
_mysiak_ said:
As far as I know it's SW limitation, affecting mostly Android phones (not sure about Apple devices, I don't own any). My phone and dongle come from the official EU distribution, so I assume that it's the EU version. The fix definitely removes the power limit. I do not have an US dongle (or measurement device), so can't compare them though. All I can say for sure it's that with sensitive IEMs the dongle is dead silent, there is no hissing noise. At the same time, and after removing the power limit, the dongle can drive AKG K240MK2 (55ohms) cans without problems. It struggles a bit with Beyerdynamic DT990pro (250ohm) - depending on the sound source, volume can (Google music) or won't be enough (most Youtube videos).
Click to expand...
Click to collapse
techcolab said:
Hi,
I appreciate you dont have meter to measure output but are you saying that this fix seems to increase the volume limit significantly ? The US version is supposed 1v against EU 0.5V.
Does this fix, 'feel' that much louder ?
Click to expand...
Click to collapse
Yes, it sounds significantly louder. Dongle is pretty cheap, they might even let you try it in the mortar store, so just get ready your phone and try it with your headphones. In the "worst" case you can use it with a PC (Windows 10), there it works at full power with no "hacking" needed.
I am a novice. But I need a module and good explanation on how to DIY. Can u help me PLEASE?
I am on android 10 samsung tab s7 plus rooted. Alsa installation showing error too. Will be very helpful if u make a video of it.

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