A bit disappointed at the sound quality of the JBL Synthesis on my LC. If I were to install DSP for aftermarket amps and speakers, where am I supposed to take the signal for the DSP from? Direct from head unit, splice wiring harness and feed signal into “high level input” on DSP Vs. After stock amp, splice the speaker output wire and feed “high level input” on DSP? Direct from head unit is always best I assume, but I don’t know if I will get some malfunction if I do not use the factory amp anymore or if that even possible at all.
2020 LC with Nav Audio Upgrade (1 Viewer)
- Thread starter Uwiik
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I think you're gonna be blazing new trail here. Unfortunately the factory audio system is rather proprietary and tough to hack into for significantly better sound quality. Good luck, report back.
Try turning off the DSP and auto volume feature. Then use a hard wired source.
It’s good but not as good as the custom setup in my 4Runner.
I do prefer the JBL over the ML in my LX, though.
It’s good but not as good as the custom setup in my 4Runner.
I do prefer the JBL over the ML in my LX, though.
But seriously, you can do small scale things here and there.......subwoofer/speakers/etc but it is quite a challenge to integrate new audio electronics with the factory system. Have you fully explored all the adjustments available with the factory system?
It's a glass box. It's never going to be great.
The jbl uses MOST. MOST is a proprietary audio bus, with little published on it. Each manufacturer seems to be rolling their own slightly different version. So there is no low level full range signal at the amp. You’d have to take the amp speaker level, then work with that, it’s not ideal. . .
the right ‘Tesla’ replacement head unit will probably have two channel low level ‘rca’ output, the audio world is then your oyster. These have varying levels of success at replicating all the stock integrations but they are getting close.
$850 to 1250 for the replacement HU. Then add on your dsp, amps, and speakers.
many have replaced the sub and added a sub amp, there’s a thread running around for that
the right ‘Tesla’ replacement head unit will probably have two channel low level ‘rca’ output, the audio world is then your oyster. These have varying levels of success at replicating all the stock integrations but they are getting close.
$850 to 1250 for the replacement HU. Then add on your dsp, amps, and speakers.
many have replaced the sub and added a sub amp, there’s a thread running around for that
Here is a GM specific MOST adapter. In the above pic it isn’t clear to me if an aftermarket HU was used or not, perhaps the integrator was able to source an adapter To feed signal directly to the aftermarket amps.
www.crutchfield.com
Axxess GMOS-MOST-01 MOST Wiring Interface
Allows you to connect a new car stereo and retain the factory MOST® amp, aux input, and OnStar in select 2014-up GM vehicles
www.crutchfield.com
Wow, that’s almost as crazy as open heart surgery.
- Thread starter
- #10
I am not a stranger in ripping apart my interior, just compounding informations so I don’t wreck my brand new LC.... LOL!! Can somebody point me to the thread of that @Eric Sarjeant audio open surgery? I saw some pics posted on that surgery but wasn’t able to find the full thread.
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- Thread starter
- #11
by this I am assuming that the only bypass I can do is on the speaker wiring right by the output of the factory amp right? Planning to use Helix Ultra DSP for maximum quality and most neutral signal flattening possible. Not ready for Tesla style HU unless they start producing it with proper Android with 6 or even better 8 GB of memory. I had a Tesla style HU on my LC100 and ditched it after 2 days to be replaced with proper Alpine head unit and use the resistor trick I obtained from this forum to keep the function of the factory screen.
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I stopped comparing car audio with home audio more than a decade ago. A $2000 home audio will easily beat a $30.000 car audio, I understand that. I am looking for the great sound within car audio scope and don’t mind to spend.
- Thread starter
- #13
I want to do things once and for all. Upgrading a little here and there usually put me in a spot where I swear a lot and sweat a lot looking for broken plastic clips. There is only very basic adjustment on the so called factory DSP, it’s archaic.
Here is the thread where Eric posted several photos. His posts start with #5.
forum.ih8mud.com
Factory Subwoofer Info Guide
This topic doesn’t seem to have been covered much so I thought I would post some usable info on the factory subwoofer enclosure and subwoofer replacement. Before ordering an 8 inch subwoofer replacement for my 08 LC I searched long and hard for info on mounting depth of the factory enclosure...
forum.ih8mud.com
The audio signal is on the MOST bus at the amp. So the only place to grab it is AFTER the amp, on the speaker level outputs. So the amp or HU will have already applied dsp and channel splitting or summing to the signals. There won’t be an unadulterated output available. Probably you could take the sub + the front woofer, mid, tweeter and sum for the post processed full spectrum. Then you have to flatten that house sound and re-dsp for your desired result.
Unfortunately the stock amp remains, and as these age more will fail and require $$$ replacement.
I have completely replaced the amplifier in my LX570, but it uses a different architecture where the low level L and R is available in 2 channel (and 7.1 coax digital) at the amp before amplification. The main challenge was a packaging issue fitting in 12 channel of dsp and amplification in the allotted space.
- Thread starter
- #17
that’s the plan for now to flatten the “finished” signal from speaker output wires using a very good DSP such as Helix Ultra and go down the line from there. I imagine that I would also faced with space availability problem considering I cannot remove the stock amp from under the seat. If anything break after 5 years or so, I suppose somebody already made a good replacement head unit or MOST converter... hopefully. I assume I would need to buy factory manual to identify the speaker wire assignments from the factory amp speaker output?
- Thread starter
- #18
Thanks for the link, I already read through the full thread, was just wondering if there a full build thread for the work.Here is the thread where Eric posted several photos. His posts start with #5.
Factory Subwoofer Info Guide
This topic doesn’t seem to have been covered much so I thought I would post some usable info on the factory subwoofer enclosure and subwoofer replacement. Before ordering an 8 inch subwoofer replacement for my 08 LC I searched long and hard for info on mounting depth of the factory enclosure...
You could look thru the sub thread someone may have posted the wiring diagram there for the tlc.
Here’s the high level diagram from the sub thread
forum.ih8mud.com
Factory Subwoofer Info Guide
So I just looked a the JBL System in the FSM. It is really different from the Mark Levinson! Most of the action is on F58 at the receiver and F55 at the amp. You also get two separate fused power pins at the Amp on the power ground/acc connector, so adding a DSP and one amp is pretty...
forum.ih8mud.com
