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.
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:
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:
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:
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:
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:
Then again we see the same thing and more with Toslink due to noise floor going way down:
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/
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:
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:
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:
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:
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:
Then again we see the same thing and more with Toslink due to noise floor going way down:
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/
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