New Android Head Unit Released

[HispanicPanic]

How exactly is the head unit connected to the speakers? I suspect you may be able to run an aftermarket DAC to help keep the sound clean. As far as bluetooth, the only way to do that is to upgrade the bluetooth chip. There are lots of chips out there with varying qualities, and usually only the higher end headunits contain higher quality bluetooth chips. That being said, the bluetooth chip still goes through the onboard DAC and amp. Its a chain of events that can ruin sound quality of either of those components are lacking, which sounds like they are in this unit.

[verkion]

These android HU have pre-amp outs and speaker level outs. I guess how they connect only depends on whether you have the RF amp option or not. I have the RF option and the sound quality isn't the best with the head unit I have to admit. Seems to be quite a bit of "noise" on the signal lines. Probably "dirty" power somewhere. I'm guessing a few filtering caps here and there would help but meh...when the car is on, its not like you can hear the hiss from the speakers.

As for BT A2DP audio...why not just bypass that entirely and install whatever app like spotify, play music etc. on your headunit and play it directly? I have my phone setup to auto-connect (over BT) to the headunit when it comes on, which then turns on my wireless hotspot which the headunit then connects to. Reverse happens when the car goes off and the head unit disconnects.

Lastly, there are a few people working on improving "sound quality" on these units over at XDA Forums. Nothing concrete yet for Android 8.0 ROMs though...

Thanks!
verkion

[HispanicPanic]

These android HU have pre-amp outs and speaker level outs. I guess how they connect only depends on whether you have the RF amp option or not. I have the RF option and the sound quality isn't the best with the head unit I have to admit. Seems to be quite a bit of "noise" on the signal lines. Probably "dirty" power somewhere. I'm guessing a few filtering caps here and there would help but meh...when the car is on, its not like you can hear the hiss from the speakers.

As for BT A2DP audio...why not just bypass that entirely and install whatever app like spotify, play music etc. on your headunit and play it directly? I have my phone setup to auto-connect (over BT) to the headunit when it comes on, which then turns on my wireless hotspot which the headunit then connects to. Reverse happens when the car goes off and the head unit disconnects.

Lastly, there are a few people working on improving "sound quality" on these units over at XDA Forums. Nothing concrete yet for Android 8.0 ROMs though...

Thanks!
verkion

Well there's a whole chain of sound that can be messed up along the way. If there isnt a hiss, but you still notice degraded sound quality, its probably the chip that converts the digital signal to analog. Is there a USB connection on these? If so, it would definately be worth it to use an external USB DAC (Digital to analog converter), then pipe that out to your RF amp. If your sound was clean prior to the android HU install, you can bet that the issue is everything prior to the RF amp. If the sound problems are still there using a good usb dac, then its probably the android software itself. At that point, i'd try different apps.

When testing sound quality, try not to use pandora or anything streamed. Download some songs you know really well in FLAC or 360+ kbps bitrates. I'm on factory base speakers, and when i connect my ipod with 360kbps bitrate music, it sounds amazing. I've had people compliment me left and right how amazing the speakers sound.


I've spent a ton of time researching sound system stuff for my home entertainment center, and have tested all kinds of different headphones, speakers, DAC's, amps and such.

Songs i use to test sound systems:
The Juliana Theory - Congratulations. This song is excellent for testing mids and trebels. If you have weak mids, the bass drum will sound meh, but if mids are strong, the drums will pack a great punch.
M.I.A - Double Bubble Trouble. This song plays well across the entire spectrum, emphasizing bass and vocals. A well balanced system will shine with this song as crystal clear vocals are often a casualty of bass.
Knife Party - Boss Mode. This song is extremely FULL of all audible frequencies. It will highlight any weaknesses in a system. Poor Analog conversion will sacrifice the songs clarity, poor amplification will make trebel harsh, and speakers lacking in any area of the audible spectrum will leave gaps in the sound that are very obvious.


I've played the 3 songs above for friends at home and they feel like that old school maxwell logo. And its just a simple 2.1 setup. It's just spec'd properly and fed with high quality bitrates.

img-1005-48181-5204-large.jpg

[verkion]

I think a few people have tried the USB DAC route but I'm not 100% sure they have it working on the Android HUs yet. Could be some libraries missing that need to be added (which maybe some have done already). I'll check on XDA.

There are wiring diagrams plus internal wiring diagrams for the RF amps in on Evo's that I've found on the various Russian sites: http://mmc-manuals.ru What I really want to be able to do is control the amp settings (EQ etc.) like the stock HU could. (At least, IIRC I think the DSP was done in the RF unit/amp as opposed to the HU.)

Thanks!
verkion

[Dfarmer0033]

Anyone experiencing issues with the ELM327 not connecting to the ECU? It is connected to the HU but sometimes it will not connect to the ECU.