Need to find out what amp you’ve got back there. It should be a pioneer or jbl and then you can move forward from there.

Edit: I just saw your pic of it. Can’t really tell the brand though. Maybe you can get your phone camera around inside?

eBay is only showing a pioneer. That will be an analog straight from the deck to the amp. For mine I bought a wiring harness from pac I believe and it made the install clean and simple.

I’d check pac’s website to get the harness at the least - or maybe eBay has it. It’s like $30. I tried a couple different offerings- one was from pac where you install at the digital signal up front behind the head unit.

wasn’t impressed with the dsp and software not to mention some functionality was lost (I think it was only half the steering wheel controls worked). I ended up just going from the harness to a kicker key lock with two rear channels bc they’re full signal.

 

Need to find out what amp you’ve got back there. It should be a pioneer or jbl and then you can move forward from there.

Edit: I just saw your pic of it. Can’t really tell the brand though. Maybe you can get your phone camera around inside?

eBay is only showing a pioneer. That will be an analog straight from the deck to the amp. For mine I bought a wiring harness from pac I believe and it made the install clean and simple.

I’d check pac’s website to get the harness at the least - or maybe eBay has it. It’s like $30. I tried a couple different offerings- one was from pac where you install at the digital signal up front behind the head unit.

wasn’t impressed with the dsp and software not to mention some functionality was lost (I think it was only half the steering wheel controls worked). I ended up just going from the harness to a kicker key lock with two rear channels bc they’re full signal.

looks like to get a full signal, this use has used rear ch. So these 2 ch will go directly as high input to Helix v8, than you could at align them in helix software and also get a proper line input correction with helix input section. And you should be all set. Get the harnes and hook up speakers using that for easy and clean of installation. And you be golden. I don’t think you will lose any functionality that way. Unless I’m wrong..
You might need to find center ch for phone calls and add that in as high input. But it shouldn’t be difficult if you have wire harness and know which wire is for what. [/QUOTE]

 

It’s a Pioneer

edit- I did see a Lexus harness on Pac’s website (attached) but I’m not sure if I’ll be able to keep all of the factory functions like steering wheel controls etc

 

As others have mentioned there is no digital signal to tap into. You’re going to have to either use an external or a dsp/amp that will accept high level (speaker inputs) . Keep the bass/mid/treb controls flat then tune via your dsp.

 

Thanks- it looks like the easiest way will be to get full signal from rear left and rear right and I’ll also pull the center channel for phone etc. all with an APH-TY02 harness from PAC.

 

What is left/right speaker level input on that diagram?

 

Great question- I pulled the diagram from another Lexus forum. It’s been accurate so far but I have yet to fully verify the pin out diagram for the 30 pin connector. The amp model is 86280-53250 and it’s in a ‘23 Is300 non-ML, non-nav.

 

Purely speculating here, but they might be the left/right signal from headunit into amp and maybe TMUT is what tells the amp your on a phone call, changing output accordingly.
SPD probably speed dependent volume.

As far as hooking up the helix though i think grabbing signal from the rears and the centre would probably still be the best/easiest bet from a retaining factory function perspective. Would only be worth considering differently if the factory amp does nasties to the signal.

 

This is exactly what it could be a left/right signal from the headunit to the amp! But you need to check everything first, one option then another, and the optimal solution will be found)))

 

I’ve got the same problem in a 16 gs350 with ML. Currently tapped the front dash speakers and doors to an helix v8 mk2 and does not look like a full signal even when summing the channels. Got a 2nd Ty02 harness to tap the rear channels to see if there’s improvement. Just have not had the chance to do it yet.

 

Did you ever finish your build? I'm trying to plan one out for my 2015 IS350 with ML (just in the research phase rn) and would love to know what different equipment you used/setted on and what your level of success was in comparison to the OEM setup and audio quality. Like, were you able to maintain most of the controls through the head unit and steering wheel functionality?

 

Since this thread started i now own an 2015 RC350 and have a bit more info for lexus in general.

Anything non-nav + non ML there is a pacamp pro interface available, use it if your headunit is the compatible type.

Nav + non ml. Most(digital) signal into amp, no integration options available (non navigation doesn't work). Stuck with reassembling signal after factory amp, need 5 inputs for a L+R.
Processor needs to be able to correct for all pass filters on the input to correctly sum the signals.

ML system haven't seen any interface options available, will likely need an 8 input processor to recreate a full L+R signal.

You don't necessarily need to recombine everything back together, if the factory signals have enough overlap and cover the bandwidth you want could just route them 1 to 1.

Swapping to a different spec of factory sound system is pretty much a no go.

 

This is strictly for my application so yours could vary. From the start, mine is non-ML. I initially used an APH-TY02 harness adapter to pick up signal out of the factory amp (you have to pick up after or you lose factory volume control). I used my DSP Amp (ADDSP 1200.8AT) to sum the signal and get full range of signal. The harness adapter also hooks up to the speaker outputs - just match the factory positive and negative based on wiring diagrams available online then test for accuracy and re-pin the harness as needed to line everything up. Overall this worked ok as I could stream through wired Apple car play or just Bluetooth to the DSP amp. I retained full factory radio function and steering wheel function.

Shortfalls- The factory amp applies various tuning to the signal and also appears that it rolls off signal below 30hz. I didn’t have the time, equipment, or knowledge to address any of that.

My solution- I choose to run optical input from my phone to DSP amp via an SMSL PO100 PRO MQA DDC XMOS XU316 Digital to Analog Audio Converter. Overall easier signal to work with, no issues with any factory amp filtering/tuning, and I use a bass volume and master volume knob directly wired to the DSP amp. I’ve been happy with it despite not using the steering wheel or radio buttons.

 

So I've got the sameharness adapter and am trying to get my JL Audio FiX82 and TwKD8 to get the singal by feeding it from the harness to the DSP, and from my amps back to the shorter side of the harness to leverage the factory wiring but with after market amps. And I am running into the volume issue, where it only goes up to 12 and stops.

How did yougrab the signal after the amp while using the APH-TY02 harness? Did you use the shorter side of the harness to feed the DSPs?

 

So, my interest in this first peaked when I saw the clublexus thread below on audio upgrades for the ML amp by a member here actually, @patriot34. After looking around those forums a bit and then finding a lot more information on this site, I’m sort of trying to emulate what patriot34 did a bit but I’d like some clarification and confirmation before I start to slowly acquire equipment.




ML Audio Overhaul - Decades of Dominance - ClubLexus - Lexus Forum Discussion
https://www.diymobileaudio.com/threads/need-input-for-2015-gs-350-with-mark-levinson.433885/
https://www.diymobileaudio.com/threads/lexus-gs-350-mark-levinson-system-help.436707/

Here is what their system roadmap looked like:

So I have a couple of questions.

First off, would it be possible to consolidate the audiocontrol loc and minidsp into one unit? For example, if I want to spring for a more buyitforlife type purchase, would a helix pro mk3/ultra (8 channel high level inputs, 10/12 RCA outputs) be fine to accomplish the tasks of getting the high level speaker outputs from the ML amp, summing channels to get a full range signal and then tuning that signal and outputting to several 4 channel amps (helix m four) and perhaps a helix M one for the sub, which then powers the speakers? Most likely I would not implement the tweeters in the pillar like in the photo and instead do the scanspeak 10F full range speakers in the dash corners and center, so 10 channels output would get me the stock number of speakers but if I got the 12 channel dsp then I could add tweeters if I want to in the future.

Secondly, in that same consolidation aspect, why could I not just take it a step further and instead of 3 or 4 separate 4 channel amps, could I not just get one 10/12 channel amp and power all speakers except for maybe using one separate amp for the sub? Or even just using a helix v twelve dsp mk2, which has 12 high level inputs and 12 speaker outputs and 2 RCA out. I assume perhaps you tax an amp more with all of its channels used and outputting enough power to each channel instead of splitting the work amount other amps but would I notice a cleaner or higher powered signal going separate amps vs all in one (excluding the sub maybe)?

Lastly (this one may be totally wrong in my head so be gentle lol), as shown in the image of the system, the rear oem speakers are left unchanged, which is what I would likely do to start. However, as the outputs of the ML amp would go straight to the dsp high level inputs, could I just leave the outputs for the rear unchanged and instead of rerouting them to the dsp, I could leave them connected like stock and the factory amp would still power them with the stock eq? Would this then allow me to potentially use a dsp and amp with less inputs/outputs? I get the sound would probably not mesh well but is it still viable? I ask because perhaps I could just keep rear dash speakers and door woofers as rear fill without having to spend more on a dsp with all the needed i/o. I also thought I read that the center dash speaker is where the navigation and other oem headunit tones/voice cues output from, so I was thinking if I leave that like stock as well maybe I could keep all of the sound cues that come from the head unit. Or would it still make sense to use a route ML amp output for rears and possibly just output the signal one to one if I don’t want to mess with separate tuning/crossovers for those specific group of speakers? Although from a resonix video going over the dsp software it looks like I could tune them to be rear fill anyways through the dsp but if I could do less work for the rear that would be cool.



At the end of the day, I’d like to obviously improve on ML sound system but at the same time I’d like to keep as much functionality as possible from the head unit and steering wheel controls. If I can’t keep functionality like the oem volume knob with the dsp/amps I listed then so be it but I’d like to try to if possible. Also, sorry that was a lot of questions but I figured it you all would be the best sources of information since y’all have done something similar more or less with your lexus vehicles.

 

Would definetly go with a standalone DSP with 8 inputs, or potentially a P6 with an aux input HEC card. Id recommend the standalone for amp flexibility.
Factory signal will have EQ and have some all pass filters to correct on the input

If you wish to retain the ability to fade to the rear using the factory headunit, you MIGHT need more then 8 inputs.

I can't recall wheter the dash fronts in the mark levinson are separate channels for the dash mid and tweeter, or a single channel with a passive crossover. In the standard system the dash is a 72ish mm coax with passive crossovers driven by a single amp channel. They still call it a seperate speaker.

Another unknown is what happens with phonecalls and the center channel. I haven't tested my base system yet with phonecalls, but it sounds like it comes from the entire dash stage at least and not just the center.
ML system might be different again.

8 dsp inputs would handle everything though, worst case you lose front/rear fade from factory stereo.
So input signals would be L+R door/dash/tweeter, sub and center.
If dash and tweet are one channel with passive, could then be L+R door/dash/rear + sub and center.

If on the other hand your primary music listening will be done via digital input from phone or DAP, then you dont need to worry all that much about summing and "fixing" the factory signals as you would only be using them when on phone calls.
Could still have phone connected via Bluetooth to factory system but then route audio out via USB to a duok u2 or smsl 100. Would retain all factory functions except for volume control

 

They're using the same (1+1) speaker for each of the three dash locations. I assume this just means its a tweeter and midrange in one? I opened up the heat shrink and there's just a 3.3uF cap inline with the wire connected to the positive top tweeter wire terminal, and nothing wired with the supposed mid, bottom wire terminal. So does that mean the tweeter is just mounted directly above the midrange?

I suppose it could just be a full range speaker, as it does kind of look like the scan 10F 8414 magnet but then why the two separate terminals. Plus, when measuring ohms with a multimeter for both terminal locations, I'm getting 6 ohms at the presumable tweeter location and 7.2 for the bottom mid terminal after it settles down and adjusts to one value.

Also, haven't had time to check whether its only the center channel or the entire dash stage for system audio like phone calls and navigation directions but I'll report back later this week.

Nonetheless, appreciate all the info, definitely going to start saving up for a standalone DSP. For the time being though, I gonna mess around with the scan 10F 8424 mids and a 6 ohm tweeter (perhaps some variant of the Bliesma T25) wired in parallel with a cap for each (68 uF and 8 uF) in each corner and another scan 10F or 10M in the center. Been doing more research on passives and messing around with xsim and so I might try designing a higher order passive crossover (some RLC variation) if the above doesn't sound good enough but I'm hoping the potentially off-axis signal being reflected off the windshield from the mids rolls off enough around 4khz for the tweeter to somewhat smoothly take over the higher frequencies.

 

That is a coaxial speaker, so a midrange with a tweeter mounted where the dust cap would be.
There are 4 terminals because the mid and tweeter each have a seperate channel, ie fully active.
The cap inline with the tweeter is likely a protection capacitor.

You shouldnt need to mess with passive crossovers, you've already got two seperate amp channels going to each corner.
You would need to do some frequency response measurements on the factory amplifier channels to see where the factory is crossed over.

Also means you will need a DSP with at least 8 highlevel inputs to sum it all together for a fullrange Left/right stereo signal.
Dash tweet, dash mid, door, sub.

For comparisons sake, the base audio also has a coax speaker, but both are driven by the same amplifier channel and there is a inductor and capacitor passive crossover network on the speaker.
There is also some significant EQ cut on the amp channel output right where the two crossover.

10F and a bliesma would be a tight squeeze in the dash location if you want to keep it under the factory grill, at least in my RC

 

Coaxial makes a lot of sense, it was even listed in the links I listed earlier, whoops!

I also didn't think about the fact it was active already, so I'll probably tweak the cap values used so they are strictly for protection purposes. I'll have to do some measurements as you said though to see what I'm working with. However, I have one question on the 4 terminals of each oem dash speaker and both tweeter and mid terminals having a separate channel. How does that work when there is only two pins in the speaker connector and what seems like two individual wires going to each pin?

It looks like yellow and green go to the same connector pin and black and purple go to the other. The yellow and purple then go to the bottom speaker terminal and the black and green to the top speaker terminal. Therefore, aren't the yellow and green and then black and purple just wired together and thus tweeter and mid speakers just wired in parallel and presumably being fed the same signal and part of the same channel?

Also, this is what I was thinking in terms of speaker placement, I ordered the wrong dash covers (nonML) so this implementation wouldn't fit, as the dimensions are a bit larger than the ML dash speaker covers but I've measured it and think I can just barely squeeze it in, might have to raise it up a few mms though.

 

 

Keep the dash under 4” for those three spots. Get signal from rear channels, they are full signals. This would mean you’d only need those two rear channels to supply the full range stereo signal.

The dash, doors, and sub are also real close to full signals, if not full altogether - I just didn’t have time to run frequency tests on them. The eq’ing mentioned in previous comments is likely from the oem dsp settings (sound leveling, surround). These should be turned off completely if you’re running a dsp.

If you decide to run a tweet and a mid off one channel, you’ll need to use a cap to block the bass signal to the tweet since they are likely getting full range signals. This would apply with or without dsp.

This is assuming non ml w/ nav.

In addition to running smsl as a source, people have had great results from CarPlay upgrades from beatsonic and grom vlt2. And most people have good things to say about the Chinese non branded carplay adapters as well. This allows for lossless playback via wired and usb, and of course lossy playback from Bluetooth.

 

Keep the dash under 4” for those three spots. Get signal from rear channels, they are full signals. This would mean you’d only need those two rear channels to supply the full range stereo signal.

The dash, doors, and sub are also real close to full signals, if not full altogether - I just didn’t have time to run frequency tests on them. The eq’ing mentioned in previous comments is likely from the oem dsp settings (sound leveling, surround). These should be turned off completely if you’re running a dsp.

If you decide to run a tweet and a mid off one channel, you’ll need to use a cap to block the bass signal to the tweet since they are likely getting full range signals. This would apply with or without dsp.

This is assuming non ml w/ nav.

In addition to running smsl as a source, people have had great results from CarPlay upgrades from beatsonic and grom vlt2. And most people have good things to say about the Chinese non branded carplay adapters as well. This allows for lossless playback via wired and usb, and of course lossy playback from Bluetooth.

All of the carplay/Android auto units including the replacement screens I've seen use the factory Aux input to get sound into the system and intercept the factory screen and touch pad signals.
Having wireless android/carplay would let you use a smsl on your phone and control via factory though.

I have 2015 RC, non ML with navigation.
My rears (single side 6inch, no 2 way, no parcel shelf 3.5) are not full range signal, front signals not full range and have eq, door signals have an APF, different for left and right.
Measured with sound levelling and surround both off, using helix AISA measurement mode, measurments taken in pctool, REW and open sound meter.

One picture is the signals for sub, door, dash.
Other picture is the sum of the two door signals, showing the results of the factory all pass filters.

 

Did you do a manual frequency sweep to audibly confirm the helix measurements.

 

I played Helix ISA track from a usb drive and ran the ISA and AISA in Pctool.
For REW and Opensound meter i used the aux in jack centre console with an output of my audio interface.
REW I took full range sine sweeps with loopback.
Opensoundmeter generates pink noise etc.

These are measurments of the electrical signals out of the factory amp, the Helix is only involved as far as being a glorified line output convertor so I don't blow up my usb audio interface.

What do you think could be happening that could make these measurements unreliable?

 

An, I see - good job then. That’s interesting they’ve modified the typical tuning that we see across most other models. Does the rc350 come with a pioneer amp or is it jbl? If it’s jbl then that would make more sense as I’ve never had a Lexus with jbl.

Regardless, if you have to use all 8 inputs to get a full range stereo signal, by all means do so. If you can do it in fewer, even better.

I’ve gotta say, this Lexus audio technology is so antiquated - even for being nearly a decade old it’s dated.

 

Mines Pioneer.
5 signals to get full range left and right, if I didn't want to swap between factory system and a phone as a digital source on the same tune i wouldnt need to blend the sub in.

Ignoring the track pad and the UI experience, dont know if i fully agree about antiquated, mines fully active (ignoring the coax mid to tweet XO) with signal processing and all fed and controlled via a MOST network.

I imagine if they were more popular cars with aftermarket demand there would be a MOST unit available, like for all the bigger manufacturers.
some part numbers for headunit, amp and the amp MOST connector if your interested.

 

I'm really appreciative of finding this thread. I've been looking all over ClubLexus and YouTube since I purchased my 2014 Lexus IS350 (w/ nav but w/o ML) 5 months ago - with more confusion than answers. I really wish it was as simple as many of the German vehicles, offering plug and play kits

I'm not too sure how the ML audio sounds, but the base system is one of the worst I've ever heard in any vehicle, far worse than my older 07 IS250 and I knew I needed to start figuring out a custom system.

I had originally thought about removing the factory amplifier and going for an Arc Audio BlackBird (8Ch 75W + 12Ch DSP) to power an active 3 way front stage - 6.5" for the doors, 3" midrange for dash corners and custom mounted tweeters (Not using center speaker) - but it seems that this idea won't work.

I apologize in advance, as I've only been researching car audio for around 5 months, but I had some questions reading this thread over, specifically on what @Matt2023 mentioned. I understand that I will need to tap into each speaker wire individual AFTER the factory amplifier. This confuses me a bit, as I thought the DSP should typically come before an amplifier, so how exactly would the input work on the DSP side? I also don't fully understand how you would then amplifiy the system after the DSP. Any insight on this would be greatly appreciated, inlcuding if a DSP AMP would work as well. Nearly pulling my hair out trying to figure this out.

Other option is just getting a DSP AMP with bluetooth/direct functionality to connect my phone or a Fiio DAP directly, but I'm worried about resale value as the cars factory system would fully not work this way.

 

@rubbertoe i am only intimatly familiar with the RC, so take the following as more of a probably. There may be some IS/RC differences, and more again some with the sales region difference. That said, IS and RC have the same dash and headunit styling.
I also have the luxury, not a F sport, so you may also have noise cancelling or artificial exhaust sounds to contend with, i honestly can't recall all the features by model and model year, let alone sales region.

There are interfacing solutions available for non-nav units, also interfacing solutions for later model years with ML.

Non ML with navigation factory setup will likely be a digital MOST signal into the factory amp.
This signal will contain the audio information for music and phone calls, and likely also fader info, volume level, sound levelling, surround sound processing. Long story short, factory amp does more then just make the signal louder.

Because of this, to retain full factory functionality, the solution is to take the speaker outputs of the factory amp into the high level inputs of a DSP, do what you want to them, then send them on to your aftermarket amps and then your speakers.

So system would be Headunit > factory amp > DSP > aftermarket amp(s) > speakers.

You can have it setup like that and working factory like, and also feed directly into the DSP from your phone when you want, doesnt have to be one or the other. Just need a DSP remote control for the volume.
Would be
Phone > DSP > Amps > speakers

Could also consider something like the Helix BT streamer, these have the ability to handle phone calls aswell so completely eliminate the factory headunit and amp but still have phonecalls. Is especially attractive for when the expensive factory headunit or amp dies, which isnt uncommon.

DSP AMP just combines two stages into one physical unit, is more convenient for install and wiring, but with less flexibility regarding amplifier power/selection and system changes.

Regarding resale, you would simply remove your aftermarket system and plug the factory amp outputs back into the factory speaker wiring. There is ZERO need to permanently remove or alter any part of the factory setup.
To make this easy you want to get an amplifier T-Harness, several companies make them, model should be APH-TY02.
This gives you access to the amplifier outputs and factory speaker wiring without having to cut anything factory, simply plugs in.
Can utilize the factory speaker wiring without an issue, adapters for the factory speaker plugs are available, would just have to run another pair of speaker wires to your your tweeters for a 3 way.

Photos are my amplifier T-Harness and the speaker adapters, 32 is the doors, 45 is my dash corners.

 

@Beardr8 I have to admit a mistake here, wont be full active already, when you said 4 pin i made an assumption based on a different 4pin Toyota connector without actually looking too hard at your pics, when in fact that looks like the same connector I've got in mine.

 

No worries! In that case, I'll keep the cap values the same for now then. But I'm gonna mess around with different values for the tweeter cap soon. Didn't sound too bad from initial tests I've done but the tweets were facing on axis so I'll be curious to see what they sound like once I get the correct dash speaker covers modded.

 

I'd like to know why? When I changed my battery everything info center wise is not rebooting or loading, the only thing working is the back-up camera. No audio, nav, Bluetooth and all controls on steering wheel? On a 2016 lexus IS 300 fsport. Any ideas?