MekedeTech DUDU7 Android Head Unit Review

[Mark185]

DUDU7 RCA output voltage is 4 volts and fairly low distortion compared to other Android head units but the optical output is better. Optical also eliminates the potential for a ground loop between head unit and DSP which can be a difficult problem with some cars. If DSP output is 2 volt maximum, you will adjust your amplifier input sensitivity for that input voltage. Every amplifier I have seen has some form of input adjustment. Ideally, you would use an oscilloscope to set the amplifier input by measuring the speaker outputs of the amp while feeding a 1000 Hz signal from the head unit to the DSP. If you do not own an oscilloscope, there are other ways. Room EQ Wizard (REW) is software that can be configured to do this using your computer's sound card. There is a YouTube reviewer named RAWCat that has some excellent videos and pdf writeups that describe how to do this. There are also some fairly inexpensive battery powered scopes you can buy.

Another reason to do this with measuring equipment is just because your DSP claims 2 volt maximum output, that does not mean 2 volts with no distortion. I have a Dayton Audio DSP408 that claims 4 volt output but the sine wave out starts to distort at about 1.7 volts on my unit. It is very easy to see this on an oscilloscopt. Therefore, I have to be careful with how much I boost signals with the equalizer and I have to set my amplifier input accordingly. The optical in signal is not the problem.

A DUDU? will not be the weak link in the system. The DSP will be area of concern based on only 2 volts output. Optical signal will have very low noise and distortion even with the flaws Amir measured. The DSP output is what you need to be concerned with. That means you have to set the DSP gain for maximum undistorted output and then set the amplifier gain.

The description above is a very basic explanation of how to set gains. There are probably folks who can explain it better but I wanted to give you a sense of what is involved if this is not something you are familiar with. REW software is free and I highly recommend you learn to use it if you have not tried it already. There are more than a few really good tutorials online and probably some excellent info on this forum.

 

[Ovovo]

DUDU7 RCA output voltage is 4 volts and fairly low distortion compared to other Android head units but the optical output is better. Optical also eliminates the potential for a ground loop between head unit and DSP which can be a difficult problem with some cars. If DSP output is 2 volt maximum, you will adjust your amplifier input sensitivity for that input voltage. Every amplifier I have seen has some form of input adjustment. Ideally, you would use an oscilloscope to set the amplifier input by measuring the speaker outputs of the amp while feeding a 1000 Hz signal from the head unit to the DSP. If you do not own an oscilloscope, there are other ways. Room EQ Wizard (REW) is software that can be configured to do this using your computer's sound card. There is a YouTube reviewer named RAWCat that has some excellent videos and pdf writeups that describe how to do this. There are also some fairly inexpensive battery powered scopes you can buy.

Another reason to do this with measuring equipment is just because your DSP claims 2 volt maximum output, that does not mean 2 volts with no distortion. I have a Dayton Audio DSP408 that claims 4 volt output but the sine wave out starts to distort at about 1.7 volts on my unit. It is very easy to see this on an oscilloscopt. Therefore, I have to be careful with how much I boost signals with the equalizer and I have to set my amplifier input accordingly. The optical in signal is not the problem.

A DUDU? will not be the weak link in the system. The DSP will be area of concern based on only 2 volts output. Optical signal will have very low noise and distortion even with the flaws Amir measured. The DSP output is what you need to be concerned with. That means you have to set the DSP gain for maximum undistorted output and then set the amplifier gain.

The description above is a very basic explanation of how to set gains. There are probably folks who can explain it better but I wanted to give you a sense of what is involved if this is not something you are familiar with. REW software is free and I highly recommend you learn to use it if you have not tried it already. There are more than a few really good tutorials online and probably some excellent info on this forum.

I've scope and RCA output is 4v at 34/36 volume, at 36/36 it's 4.6v (unclipped even atax volume). The DSP claims 4v RCA voltage and it only output maximum of 2v unclipped. For RCA I didn't have to increase gain much as I run 50w rms speakers and Amplifier has 75w of clean unclipped power per channel.

The problem is with the subwoofer channel which needs to be at 24v (2ohm 300w) for my subwoofer to be at RMS power which means gain would have to be increased a bit higher thab currently with RCA, which in turn can introduce some potential noise.

Subwoofer channel can output 600w rms at 2 ohm so still within the clean output range.

 

[Mark185]

Your DSP output at 4.6v is good. Glad to see it is better than published specifications. I should correct what I said about the Dayton DSP-408. RCA inputs clip at 1.6v. The output RCA clips at 2.3v.

Your DSP should allow you to increase gain for the subwoofer channel(s) independently of the other channels. Any increase in noise on subwoofer channel(s) should not be audible.

 

[Mikescotland]

Apparently the output never actually goes over 44.1kHz, and is actually resampled from 44.1kHz even though the menu has 48, 96 and 192kHz.

Just thought people might want to know.

Hello
No, you misunderstood my post on DUDU forum.
1. spdif > always goes through Android pipeline, 48 kHz. And then it's resampled to chosen spdif SR (48, 96, 192 kHz). "passthrough" mode only turns off completely internal AKM DSP. Volume adjustment works. So, if your file is 44.1kHz/24bit goes first to 48/24 and then second time to 96/24. Power amp - watch which audio output settings you use, I'm some cases also bit depth is converted to 16 bit before going back to 24 - that's without floating 32bit ON. Internal player - no idea about bit depth as can't see it. Possibly also goes first to 16 bit before conversion to 24bit.
2. USB Audio also always goes via Android pipeline 48 kHz, unless you use a player that directly takes over USB, like USB player pro etc. Then you have bit perfect playback. No volume adjustment and no any other sounds (navi, calls, radio doesn't work until the usb driver is released by such player).

My biggest question to them was WHY introduce 96 and 192 spdif (let alone 192/24 is over standard max bitrate for optical, my dsp is "choppy", as this doesn't make any sense, FR is always max 22-23 kHz). They answer was quite bizarre - because compatibility and "things work better with higher SR". Personally haven't seen any device that has 96kHz but lacks 48kHz. Also generally 96 and 192 kHz spdif is tad quieter (in measurements, can't hear it) than 48 kHz.
And... They finished the answer with even more bizarre "to get the best of the pass through spdif is to play High Resolution music files". Again. What for if that's being resampled by poor android audio stack to 48 kHz and then resampled again to, let say 96kHz.
Also after the firmware update, spdif now looks like 0dBfs is really full volume (need to measure) but they introduced something that raised my eyebrows. Now volume adjustment is linear... Was logarythmic before. Allegedly, users wanted it (couldn't find who though). So now, volume at just 3, pumps quite a lot of watts to your amps, if you have powerful external speakers, and you really never go over half of the volume control for super loud music. Listening in a quiet car is problematic, it's either whisper, or next one adjustment up, you can't speak with a passenger.
Dudu offered resolution - turn the gains down on your amp or dsp.. Hell, no, if I have 300W amp, I want to be able to squeeze 300W from it. I paid for it. Not to castrate my whole system just to have more granular volume control at lower volume. Discussion about this is pointless with them.
For their claims before I purchased the unit that is supports 44.1 and bypasses android stack, for my questions about it, they stopped responding.
Also people complain in the new firmware that DPI is not adjustable. The UI letters and buttons are designed for 20 inch monitor and not scalable. On 10 inch model the navigation and player buttons on home screen are - letters around 1.3mm high, buttons (Inc volume) are 6x6 mm. App buttons around 1cmx1cm. Forget pretty much about operating it while driving.
Also, themes are a quite a bit visually outdated and for me, with steering wheel on the right hand side, configuration to swap bars etc doesn't really exist.
And finally, unit is too bright in the night. Burning your retinas after upgrade. There is a grey overlay mode, called "extreme night" but it just looks like a milky bright fog, still I have to turn off the display driving in the night.
Audio wise - it's not bad even with these shortcomings, I wish they were honest before selling about SR over spdif, UI wise - it's a disaster when driving.

 

[goldenears]

For their claims before I purchased the unit that is supports 44.1 and bypasses android stack, for my questions about it, they stopped responding.

What's the other unit?

 

[Mikescotland]

What's the other unit?

What do you mean by other unit?

 

[goldenears]

What do you mean by other unit?

Sorry, I misread the post. Ignore that.

That linear volume thing is crazy. Why the hell would they do that?

 

[goldenears]

Hello
No, you misunderstood my post on DUDU forum.
1. spdif > always goes through Android pipeline, 48 kHz. And then it's resampled to chosen spdif SR (48, 96, 192 kHz). "passthrough" mode only turns off completely internal AKM DSP. Volume adjustment works. So, if your file is 44.1kHz/24bit goes first to 48/24 and then second time to 96/24. Power amp - watch which audio output settings you use, I'm some cases also bit depth is converted to 16 bit before going back to 24 - that's without floating 32bit ON. Internal player - no idea about bit depth as can't see it. Possibly also goes first to 16 bit before conversion to 24bit.
2. USB Audio also always goes via Android pipeline 48 kHz, unless you use a player that directly takes over USB, like USB player pro etc. Then you have bit perfect playback. No volume adjustment and no any other sounds (navi, calls, radio doesn't work until the usb driver is released by such player).

My biggest question to them was WHY introduce 96 and 192 spdif (let alone 192/24 is over standard max bitrate for optical, my dsp is "choppy", as this doesn't make any sense, FR is always max 22-23 kHz). They answer was quite bizarre - because compatibility and "things work better with higher SR". Personally haven't seen any device that has 96kHz but lacks 48kHz. Also generally 96 and 192 kHz spdif is tad quieter (in measurements, can't hear it) than 48 kHz.
And... They finished the answer with even more bizarre "to get the best of the pass through spdif is to play High Resolution music files". Again. What for if that's being resampled by poor android audio stack to 48 kHz and then resampled again to, let say 96kHz.
Also after the firmware update, spdif now looks like 0dBfs is really full volume (need to measure) but they introduced something that raised my eyebrows. Now volume adjustment is linear... Was logarythmic before. Allegedly, users wanted it (couldn't find who though). So now, volume at just 3, pumps quite a lot of watts to your amps, if you have powerful external speakers, and you really never go over half of the volume control for super loud music. Listening in a quiet car is problematic, it's either whisper, or next one adjustment up, you can't speak with a passenger.
Dudu offered resolution - turn the gains down on your amp or dsp.. Hell, no, if I have 300W amp, I want to be able to squeeze 300W from it. I paid for it. Not to castrate my whole system just to have more granular volume control at lower volume. Discussion about this is pointless with them.
For their claims before I purchased the unit that is supports 44.1 and bypasses android stack, for my questions about it, they stopped responding.
Also people complain in the new firmware that DPI is not adjustable. The UI letters and buttons are designed for 20 inch monitor and not scalable. On 10 inch model the navigation and player buttons on home screen are - letters around 1.3mm high, buttons (Inc volume) are 6x6 mm. App buttons around 1cmx1cm. Forget pretty much about operating it while driving.
Also, themes are a quite a bit visually outdated and for me, with steering wheel on the right hand side, configuration to swap bars etc doesn't really exist.
And finally, unit is too bright in the night. Burning your retinas after upgrade. There is a grey overlay mode, called "extreme night" but it just looks like a milky bright fog, still I have to turn off the display driving in the night.
Audio wise - it's not bad even with these shortcomings, I wish they were honest before selling about SR over spdif, UI wise - it's a disaster when driving.

Do you happen to have any advice about how I can get the Loudness setting to sound better?

I would like it to work like Dynamic EQ on my Denon AVR, for slightly boosted bass and treble at low volumes, but everything sounds super boomy and muddled when I activate it. I have a proper 5ch amp with a 10" subwoofer in the boot. Basically it sounds ridiculously bassy and terrible.

There's no way that I can see to calibrate the loudness setting to have less effect.

 

[Mikescotland]

Wrong forum / rop

Do you happen to have any advice about how I can get the Loudness setting to sound better?

I would like it to work like Dynamic EQ on my Denon AVR, for slightly boosted bass and treble at low volumes, but everything sounds super boomy and muddled when I activate it. I have a proper 5ch amp with a 10" subwoofer in the boot. Basically it sounds ridiculously bassy and terrible.

There's no way that I can see to calibrate the loudness setting to have less effect.

Wrong forum / topic

 

[Mikescotland]

Sorry, I misread the post. Ignore that.

That linear volume thing is crazy. Why the hell would they do that?

I have no idea. You can imagine what happens with 300W kicks and 1000W sub.
Volume from 0-1 pumps already a few watts into the speakers and at 4 you can't really talk in the car..
And no matter what you say, that at the end of the scale still all methods have max volume, but the initial curve is more granular, they don't seem to get it. It might be fine for internal 10W RMS amplifier, but majority of the users bought it for external dsp / amps.
Crazy.

 

[yoyoc]

This is a review and detailed measurements of the MekedeTech DUDU7 (also called DUDU-auto) Android Car Operating System head unit. I purchased the 9.5 inch version for US $499.
View attachment 453018
There is an explosion of these tablet like devices running Android OS with hardware that resembles what you get in a car stereo head unit. Prices start below $100 for very low-end offerings and go up to about $600. You likely have not heard of any of them but they are getting very popular among enthusiasts. With advent of Android Audio and Apple CarPlay, and elimination of CD drive and navigation, traditional head units from likes of Sony, Pioneer, Kenwood, etc. have become expensive, low resolution devices with little functionality. The Sony ES series I was looking at costs almost $1000.

You might think that projecting your phone in the phone on a dash unit using Android Auto gets you the same thing but it does not. Android Auto is low resolution and has nowhere the response of these devices. Take look at this actual shot my device running Google Maps:
View attachment 453019
You are not going to get this level of resolution with Android Auto. Nor the instant response of the display as if it is your own recent phone or tablet. What a joy it is also to be able to download app after app and have it just run. I installed Roon player for example which I used for my testing. Youtube, Netflix, etc. all run. While Android does limit some devices from Play Store, everything I needed installed just fine.

There is an issue of how you get data to such a device. They come with a 4G SIM slot that you can purchase to get mobile data. I am just going to use mobile hotspot on my phone. As a back up, I downloaded offline maps so I don't even need data service for navigation. And if you put your music on the device, or memory stick, of course you can play locally with super responsive UI.

There is hook up for Canbus to show vehicle instrumentation and integrate better with care functionality (you have to get the special harness).

The reason I went with DUDU7 is because a) they provide 1080P and better resolution (most of these boxes are 720p) and b) they have their own software team that has build fair bit of software into these device, as far as audio functionality. The combination is both familiar and unknown at times. Figuring out for example why I was seeing a delay in one channel took quite a bit of looking, to find a poorly named option in Soundstage submenu. Then again, you get such things at DTS upmixer. The familiar came in the form of logging into my Google Account and seeing all my familiar apps offered to be downloaded, and all the usual stuff Google brings to the table.

Company support is said to be good but I could not download even their forum page due to very long load time. There is OTA update of the OS but it too just hangs and gives up. They really need to move to a proper server if they want to service their customers overseas.

Bluetooth support worked instantly with my Samsung S23 Ultra.

On the hardware front, there is the traditional RCA pre-amps and speaker output. Alas, I could not test the latter as they did not include the harness for power and speaker out!!! No, I am not kidding. The main cable is not provided and assumed you get a third-party harness. Where that would come from is left as an exercise for the buyer! I had to kluge up a couple of jumper cables just to power up the thing and wasn't going to do the same for speaker output.

On the positive front, there is S/PDIF output which bypasses the internal DAC. The DSP amp I am using has S/PDIF input which simplifies the wiring and should produce higher end to end system performance. Alas, some features such as upmixing is lost when using Toslink but other DSP functions remain. And they are quite significant features although no parametric EQ. I imagine you can download a third-party app.

Here are the other variations of this device on Amazon:
View attachment 453020
Alas, the only one that was available when I purchased it last week, was the 9.5 inch. It doesn't come with any brackets or trim pieces. Will have to see how it goes tomorrow getting it into the camper van. Note the 8 gigabyte of memory and 128 gigabytes of storage. Low end ones come with as little as 2 gigabytes of RAM and 32 Gigabytes of storage although most are 4/64.

The display is bright and high contrast indoors. Again, will have to see how it works outdoors. Mine is fixed display in that the entire guts are just a 1 inch or so block behind the display. There is a tiny fan in there that comes up but shuts off quickly. It only does that when system activity goes up such as starting some app. Otherwise, it was silent. The sides of the unit get warm but not hot with pre-amp use. There are some settings for fan for amplifier.

Finally, this thing comes with its on GPS antenna, microphone input, FM radio (sadly not HD Radio) and some other stuff I am forgetting. Look for online reviews for more.

MekedeTech DUDU7 Audio Measurements
I initially fed the unit my usual 1 kHz 44.1 kHz tone using Roon. Alas, Roon showed that it had to resample this to 48 kHz to feed to Android. I can't believe Google has not yet fixed this and followed Windows mistake by making 48 kHz the main sampling rate instead of 44.1 kHz. Using Toslink out, I could see a bunch of artifacts so I changed the test signal to 48 kHz and they got better but clearly there is an issue there with the OS audio stack. I tried using Neutron Player hoping for bit exact playback but it did not do anything different. I wish DUDU had spent time creating a bit exact pipeline like portable audio player companies have done.

Anyway, let's go with that and look at analog pre-amp out with volume adjusted to 2 volts out:
View attachment 453023
I expected a number in 80s and that is what we have. There is some hum due to use of my bench supply which in practice will not be there. SINAD may improve a hair as worst case distortion is -92 dB. Nice to see the unit going up to 4.6 volts out while still staying at 85 dB.

I have included power consumption numbers on top right. Basically it dissipates 15 watts constantly. Lowering the display brightness saves you a couple of watts. Sadly there is no suspend/sleep mode. The "Display Off" function just puts up time but the machine is still running. On that front, boot time is about 7 to 10 seconds which is quite reasonable for this type of device.

Switching to Toslink gives us better performance but seemingly limited to 16 bits:
View attachment 453024
We gain 20 dB in noise performance and of course, lose any distortion. Can't figure out why the output is not full scale even though I turned off all the processing (and enabled the option for that).

Edit: I have now tested two other Android stereos and the Dudu7 easily outperforms them:

Jitter on analog output shows data dependency so could be cleaner:
View attachment 453025

Then again we see the same thing and more with Toslink due to noise floor going way down:
View attachment 453026

Don't know what all is going on here. Good news is that the peaks around our main signal are around -120 dB so not an audible concern.

I was hoping to use the analog line level input to run more tests. Alas, I could not find a way to select that input! So this is all I have for you.

Conclusions
You have to be fairly brave to jump into this pool of Android head units. As long as you are savvy around devices like this, you can get through it although having a $30K analyzer next to you is a great help in knowing what does what. It is uncanny to be able to have a car audio product with such high resolution display and such speed. And the ability to keep installing apps on it and extending its functionality. I am hoping these offerings mature and become more westernized (shipping with China as the timezone?). I will report how the installation goes.

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Were you able to get any installation bracket dor your van?
I am interested in inatalling one DUDU7 in an older SUV dor which rhere is no custom face install kit, and have not been able to find a generic double din for it....

 

[amirm]

Were you able to get any installation bracket dor your van?

More or less. I bought a few but at the end, made a combo of the parts I bought and what came with the van. I guess we got kind of lucky in the way someone had already put an aftermarket Kenwood in there so we were able to use its trim piece.

I also bought the double dins and those did not work at all. The single DIN gave us more flexibility as we didn't have to worry about the depth of the unit.

 

[goldenears]

Wrong forum / rop

Wrong forum / topic

I'm asking about the loudness setting on the dudu7.

 

[goldenears]

I have no idea. You can imagine what happens with 300W kicks and 1000W sub.
Volume from 0-1 pumps already a few watts into the speakers and at 4 you can't really talk in the car..
And no matter what you say, that at the end of the scale still all methods have max volume, but the initial curve is more granular, they don't seem to get it. It might be fine for internal 10W RMS amplifier, but majority of the users bought it for external dsp / amps.
Crazy.

So they've said that they're going to leave it that way?

Have you reported it as a bug to them?

If so, I won't update. I haven't gone to 3.6E yet.

 

[Mikescotland]

So they've said that they're going to leave it that way?

Have you reported it as a bug to them?

If so, I won't update. I haven't gone to 3.6E yet.

Yes. Allegedly it was a request from majority of users. Haven't found these requests though.
Funny enough, they fixed spdif out max volume (0dbfs is really 0dbfs out), but introduced linear volume control. Also, it may be my subjective perception, sound signature after that change changed. Something is off and I feel like it's distorted. I'll have to remeasure my system and see. Again, this might be my perception, biased, because now everything is crazy loud.
Tried to reason with them on that linear control, but the only solution for me was "turn down the gains" on the amps. Which isn't really a solution as linear stays, albeit with lower overall loudness and castration of my amps... Then they stopped replying.
Out of frustration I reverse engineered their Raise canbox protocol and now have own diy canbox clio IIi > all functions and indicators on DUDU (doors, lights, indicators, parking brake, distance, speed, wheel angle etc). I will post the protocol on DUDU forum, as some people are interested how to build their own based on one esp32 for 5USD.

 

[Mikescotland]

I'm asking about the loudness setting on the dudu7.

Ah, sorry.
I misread and thought you were talking about kenwood avr.
No, there isn't any way to alter it. Loudness is a switch and does whatever was programmed by Dudu. No way to alter it. I don't use it, as using so called "pass through" but quickly tested and it's just a simple, quite aggressive curve loudness.

 

[goldenears]

Were you able to get any installation bracket dor your van?
I am interested in inatalling one DUDU7 in an older SUV dor which rhere is no custom face install kit, and have not been able to find a generic double din for it....

So you already have your unit and need a mount for it?

I would chat to them on alibaba, they have generic 2din mounts and also units that fit generic single and 2din.

Their chat staff is surprisingly pretty helpful, at least about mounting...

 

[goldenears]

Ah, sorry.
I misread and thought you were talking about kenwood avr.
No, there isn't any way to alter it. Loudness is a switch and does whatever was programmed by Dudu. No way to alter it. I don't use it, as using so called "pass through" but quickly tested and it's just a simple, quite aggressive curve loudness.

Yes, it seems super aggressive.

 

[dexx]

Jitter on analog output shows data dependency so could be cleaner:

Did you test the unit's own internal amp and speaker outs?

 

[Mikescotland]

Did you test the unit's own internal amp and speaker outs?

Possibly no point, as they are either shipped with TDA7803 or TDA7808. Bear in mind TDA7808 will allow only 4Ohm speakers minimum. As they are standard ICs, and the input to them is taken from AKM dsp, you can expect output in pair with their respective data sheets. RAWcat on YT did the analogue audio out (search for it) but not speaker amp outs.