2015 Genesis Sedan Lexicon 14 speaker - OEM amp replacement

[dead_again]

All,

I wanted to share the progress that I've made toward replacing the OEM amp in my 2015 Genesis Sedan with 14 speaker Lexicon system. As many of you may know the 14 speaker Lexicon system uses S/PDIF digital audio from the head unit to the amp, as well as CANBus signals to control power on/off, volume, mute, beep tone, and to play navigation prompts. Thus far I've gotten power on/off, volume, and mute working. I've documented what is required to make all of this work in a GitHub project so that you can see what is involved and what parts are required.

The part that stumped me the longest was that the Genesis uses fault tolerant CANbus to communicate between the head unit and the OEM amplifier. This is incompatible with standard CANbus so I could never get it to talk to my raspberry Pi. Once I learned that fault tolerant CANbus was a thing and that the Genesis used it, it was just a matter of ordering the right convertor and then everything started to come together.

I still don't have this in the car yet as I just finished testing the CANbus integration, but I'll be posting again once I've got it all buttoned up and ready to install to show the final product. Stay tuned, I look forward to your feedback:

As a bonus here is the amp rack ready to go into the car:

 

[dmcmi53]

Great job and I really like the GitHub write up. The only thing I missed is how you determined which amp to install that is going to allow you to capitlize more on HiFi audio quality.
I guess what I'm trying to ask is it what are the current amp limits and what are your new frequency bounds going to be?

 

[dead_again]

Well the head unit isn't putting anything higher than 48k out that I'm aware of, so we're not going to be dealing with high resolution audio. Additionally, the DSP I'm using is limited to 48k as well.

The main motivator (for me) for moving away from the OEM amp is that the built in DAC is incredibly bad, so much so that the designer of the amp has a circuit that shuts off amp output during silence to prevent noise from getting through. This can be heard on certain songs like Phil Collins - Don't Lose My Number when the song goes silent for a moment, then when the audio starts again the first part of the audio is cut off. Additonally it's quite obvious when playing anything through the system that there's a lot of audible distortion, even at low volumes. This problem doesn't appear to exist when plugging the SPDIF signal into anything else, so my conclusion is that the OEM amp has objectively bad sound quality issues.

Additionally, I just want more power. I've replaced all the front speakers with better sounding models (more on that in the build log post) and they aren't as efficient as the OEM speakers, so I needed a lot more power to get the sound I want. I am using 2 of the Soundstream Picasso Nano PN4.1000D amps for a fully active 3 way front setup with 2 channels for rear fill, because they're compact, efficient, and put out gobs of power so I'll be able to tune them down a bit to get clean power all the way to maximum volume.

 

[dmcmi53]

Well the head unit isn't putting anything higher than 48k out that I'm aware of, so we're not going to be dealing with high resolution audio. Additionally, the DSP I'm using is limited to 48k as well.

The main motivator (for me) for moving away from the OEM amp is that the built in DAC is incredibly bad, so much so that the designer of the amp has a circuit that shuts off amp output during silence to prevent noise from getting through. This can be heard on certain songs like Phil Collins - Don't Lose My Number when the song goes silent for a moment, then when the audio starts again the first part of the audio is cut off. Additonally it's quite obvious when playing anything through the system that there's a lot of audible distortion, even at low volumes. This problem doesn't appear to exist when plugging the SPDIF signal into anything else, so my conclusion is that the OEM amp has objectively bad sound quality issues.

Additionally, I just want more power. I've replaced all the front speakers with better sounding models (more on that in the build log post) and they aren't as efficient as the OEM speakers, so I needed a lot more power to get the sound I want. I am using 2 of the Soundstream Picasso Nano PN4.1000D amps for a fully active 3 way front setup with 2 channels for rear fill, because they're compact, efficient, and put out gobs of power so I'll be able to tune them down a bit to get clean power all the way to maximum volume.

That's really good stuff. Do you have a spec sheet on the OEM speakers and amp? This sounds like an interesting avenue to drive down.

 

[fjc2020]

HELP!!! AUDIO SUX
2012 3.8 speakers -door woofers replaced- Now all everything all corners distorted unclean. WTF

 

[dead_again]

HELP!!! AUDIO SUX
2012 3.8 speakers -door woofers replaced- Now all everything all corners distorted unclean. WTF

You should probably post this in a new thread. The first thing I would do is unplug the new woofers one by one until the distortion goes away. Other than that a video explaining the distortion might be helpful.

 

[Mikebrooks]

I'm curious if you have moved forward & any progress has been made. Sounded like you were almost there when you stopped.