MekedeTech DUDU7 Android Head Unit Review

[diddley]

I would go to the dealer and buy an official one and let them build it in. I know it's alot expencier but it saves you so much hassle and stuff that doesn't work.
Let the proffessionals do it. but still respect for you Amir and not giving up.

 

[Mark185]

@diddley for some of us, part of the fun is solving the problems.

 

[amirm]

I would go to the dealer and buy an official one and let them build it in. I know it's alot expencier but it saves you so much hassle and stuff that doesn't work.
Let the proffessionals do it. but still respect for you Amir and not giving up.

Except for a handful of custom shops (all of which I have seen are in Europe), none of the local shops carry such gear or install it. Instead, they will sell the old school Sony, Kenwood, etc. which are dumb displays. But you are right, if you do go with them, then they will know how to fit it to your system. It will also be easier to search for a solution as those brands are much more prevalent than likes of DUDU.

 

[MRC01]

... 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.

USB Audio Player Pro works well on all my Android devices, including ones that run LineageOS. I wonder if would work on these devices.

 

[amirm]

USB Audio Player Pro works well on all my Android devices, including ones that run LineageOS. I wonder if would work on these devices.

Thanks. I was going to try that but couldn't think of its name.

 

[Mark185]

I am getting ready to install my DUDU7 and I want to run optical output to a Helix M6 DSP amplifier. My original plan was to use the DUDU7 volume control but I forgot that controlling volume of a digital signal loses bit depth as you attenuate it. I am thinking the only way to control volume and get the most out of the DUDU7 in terms of sound quality is to buy the Conductor remote control for the Helix DSP amp. @amirm how are you installing your unit if you are using the optical output?

 

[janis93]

Hello, new dudu os beta is out.
DUDUOS 3.6E Public Beta.

It specifically tells: Enhanced SPDIF pass-through on 7870, delivering near-source audio quality

I am really interested if this boosts quality, or at least gives full level signal out of optical.
Are you able to take a look to this subject, I really want this head unit, but the optical out low volume is one thing that holds me back.

Link to the dudu forum post

 

[Mark185]

@janis93 what do you mean by optical out low volume? On my test bench, optical out at full volume into my DSP unit has no shortcomings I can detect. My only issue is controlling volume from the driver's seat in the car. I believe I will have to leave the DUDU7 at full volume and control volume with a remote controller for my DSP unit. Down side is the controller is another $200 and I have to find a place to install it but I don't see that as a showstopper. I mentioned this in my post above. Is there something I am missing or not understanding about Amir's test data with optical out?

From what I can tell, the updated DUDU OS 3.6 gives us SPDIF at 24 bit 96 kHz instead of 48 kHz. I do not see where that affects volume.

 

[janis93]

I have just googeled and read any iformation i can get. and some users have problems with native spdif optical output volume. and using something on usb ( example SMSL PO100) to get full volume output.
on dudu forum there are also multiple discussion on this topic.

for example here user get 75% of full volume after changing some settings he managet to get about 90% of the signal.
dudu forum digital output post.

Maybe I am geting something wrong here?

 

[Mark185]

Is the issue number of bits of resolution above the noise floor rather than % of full volume? If it is simply a volume issue, any DSP or Amplifier the toslink signal is fed into can compensate for that easily.

I wrote the above several hours ago. Since then I hooked up my DUDU7 on my test bench to a Helix M6 DSP amplifier. It has a 10 channel DSP and 6 internal amplifier channels rated at 100 watts each and 4 line level outputs for an additional amplifier if needed. I set the head unit to SPDIF pass thru 24 bit 96kHz. used the optical output and verified that I can boost the gain of the incoming SPDIF signal in the DSP setup. Problem solved - sort of.

The remaining problem is that the pass through signal will only work for whatever music player you are using. Phone calls, navigation prompts, and radio will not be carried on the optical signal. The Helix has a solution. I have to run line level outputs using RCA cables from the DUDU7 to the Helix. The Helix has a setting for assigning priority for the digital and analog inputs. It can be set to interrupt the SPDIF music playback if there is a signal on the analog lines for phone, navigation, etc. The down side is that using analog inputs does introduce the possibility of ground loops and alternator noise. I won't know if this will be a problem until I install the system in my 2003 BMW 540i M Sport. These older BMWs have been known to have problems like this. There is a reason many of their older models have twisted pair wiring from the head units to the trunk mounted amplifiers. My model has a OEM DSP amplifier and the signal from the factory head unit is digital. I will be removing all of that. It will be several weeks before I get the system installed. In the meantime I will be running other tests on the hardware and software.

For those who are interested, Arc Audio also makes DSP hardware and software that does what the Helix system does and they are an American company. I tried one of their DSP amplifiers and really liked their software. Their amplifiers have a good reputation for reliable builds and excellent audio performance but I returned my Arc unit for reasons unrelated to performance. The dealer that sold it shipped me an obviously used unit but represented it as new. I decided to buy from a shop closer to home that would let me use PayPal to buy it but he is a Helix dealer. I liked the Arc Audio product well enough that I am going to buy one of their units used on Ebay and compare it to the Helix. I have a Quant Asylum QA403. Not as good as what Amir uses but within my means to enhance my hobby.

 

[goldenears]

@amirm I just picked up a Dudu7 and quite happy with it.

What speakers are you getting to pair with it, and are you going to measure any car speakers?

 

[amirm]

@amirm I just picked up a Dudu7 and quite happy with it.

What speakers are you getting to pair with it, and are you going to measure any car speakers?

Hi there. I had upgraded the speakers to JBL. Bought another set for $500 but found the JBLs to sound excellent so didn't bother with swapping.

I originally did intend to measure the speakers. I might do that. It is a bit of a hassle to build a baffle for them but otherwise, I am game to test.

 

[amirm]

@amirm how are you installing your unit if you are using the optical output?

The head unit volume control works on Toslink and that is how I am using it. Are you seeing otherwise?

I did get the remote controller for my DSP that has volume control. But my main use for it is to change DSP/sub parameters.

 

[Mark185]

The head unit volume control works on mine as well using Toslink. i am under the impression that turning down the volume using Toslink reduces the bit depth and one loses some of the fidelity of the original signal. In a quiet car, I would like to get the most performance possible. I also have a Toyota Tundra and in that application, I am not so worried about loss of sound quality using Toslink to control volume.

 

[xanalog]

I originally did intend to measure the speakers. I might do that. It is a bit of a hassle to build a baffle for them but otherwise, I am game to test.

This effort sounds like a tough nut to crack.
*How would you simulate the room... ummm... environment+baffle and the location/direction of the drivers, within constraints of an RV?
The answers thru NFS would be in comparison to nothing else... would they?
Have you finalized how you are going to finish-off your RV audio adventures?
Are you putting any fore-thought to doing some video or USB hardware and cable feeds, around your RV?
Which JBL models have you decided on?

Don't get mad for asking.
Your answers will be relevant because my new-ish Xduoo X5 appears to not be up to the task of feeding my car audio.

 

[BURNART]

Hi there. I had upgraded the speakers to JBL. Bought another set for $500 but found the JBLs to sound excellent so didn't bother with swapping.

I originally did intend to measure the speakers. I might do that. It is a bit of a hassle to build a baffle for them but otherwise, I am game to test.

Hello Amirm Can you share the model of JBL?

 

[Ovovo]

With 3.6E update, Mekede claims to make sound improvements over Spdif, don't know if real world difference is audible, I was about to get a DSP amplifier to make use of optical out, worried about not getting better performance compared to RCA.

 

[goldenears]

With 3.6E update, Mekede claims to make sound improvements over Spdif, don't know if real world difference is audible, I was about to get a DSP amplifier to make use of optical out, worried about not getting better performance compared to RCA.

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.

 

[Mark185]

I understand wanting to get the maximum possible performance from the SPDIF outputs but some recognition is due. In a mobile audio environment, it is extremely unlikely that most of us can hear the difference between 44.1 kHz and higher sample rates. Likewise, the jitter that Amir measured on the optical out is more than 90 dB down and not audible for most if not all people. @Ovovo I would not let any of that deter you from buying a DSP and using optical. This is still one of the premier Android head units if not the best and Mekede has shown that they will update the software regularly unlike most other manufacturers.

Speaker location, installation, and DSP tuning will all have a much larger, more audible effect on sound quality than SPDIF sampling frequency and the measured jitter.

 

[Ovovo]

I understand wanting to get the maximum possible performance from the SPDIF outputs but some recognition is due. In a mobile audio environment, it is extremely unlikely that most of us can hear the difference between 44.1 kHz and higher sample rates. Likewise, the jitter that Amir measured on the optical out is more than 90 dB down and not audible for most if not all people. @Ovovo I would not let any of that deter you from buying a DSP and using optical. This is still one of the premier Android head units if not the best and Mekede has shown that they will update the software regularly unlike most other manufacturers.

Speaker location, installation, and DSP tuning will all have a much larger, more audible effect on sound quality than SPDIF sampling frequency and the measured jitter.

Is difference between RCA and optical substantial in audio quality? Sorry for naive question, I've got a ground zero DSP that can take optical in, however RCA voltage from DSP output is just 2v at max volume. Wouldn't low voltage make me increase gain which in turn induce audible noise?