External Amplifier adapter for Tesla

[Naonak]

As per a discussion in another thread with regards to making a "generic" adapter to allow an external amp to interface with the Tesla wiring harness, I am making this thread to foster discussion and to get an idea of how many people might be interested in this.

I have an RFQ out to one of the companies I use to make custom cables for a quote on how much each cable would be. But judging from my past experiences, the price is drastically affected by the quantity.

I'd also like to hear discussion and ideas on what might be required or desired in terms of what the final product would look like.

For reference, it would have this receptacle:

MCP SUB ASSY 32 POS HSG REC: 1534180-2 AMP

attached to bare wires, allowing you to wire up any combination of custom amp(s) to the Tesla wiring harness. This adapter would also allow you to connect to the fill speakers and not just the midwoofers + sub.

 

[JasonA-EV]

I'd be interested in one. Has anyone taken pics or made a vid of the process of getting to the physical harness?

Also, for someone like me with a late 2015 "gen2" car i guess, are all the pin outs the same? I know the factory CANbus harness/diag connector is different.

Would this work only with a UHFS setup or non like mine?

 

[Naonak]

I'm not sure if it would work with a non-UFHS system or not - the harness is really easy to get to, takes about 10 seconds and is above the drivers left knee. Just pop off the lower facade and it's right there. Getting the current UFHS amp out, on the other hand, is a royal pain in the ass. But you can just get to the harness without taking the amp out.

If you want to take your panel off and see if you have that harness and connector just dangling there or something, that would probably tell you.

There's a video from Light Harmonic that shows how to access the amp. You just need the first portion of it where you take off the panel, the rest you don't need to worry about until/unless you want to remove the amp itself.

 

[jeffb]

The non-UFHS does not have that plug and does not have the amp.

Im I mistaken or is that plug the wrong "gender"? I think you need the mating part to the one in the link. Thats the portion that is part of the car. As I recall the amp has the pins and the plug has the receptacles? When I get home Ill look to confirm.

OR....is the picture wrong in the link?


Also....keep in mind that the external amp is for the 5 woofers only.....so this would not be a complete solution for a person looking to do a total overhaul, this would only power the 8" speakers in the doors and the sub.

Also....remember the thing from the other thread about having to reboot the car after swapping amps? We dont really know yet what will happen if we remove the factory amp, does the MCU disable its low level output? Some experimenting may be in order....

 

[JasonA-EV]

So where is the amp then on non-UHFS cars? It is built in to the "headunit" or the main MCU/ display unit?

At some point there has to be a harness that connects to the all the speakers that can be tied into. This was my though process about getting a LCQ-1 into the mix.

 

[jeffb]

Its not one plug or harness, its a few....Muzzman posted the wiring diagram in the other thread, you can see it there. There are a number of plugs/harnesses coming out of the MCU that are audio system related, some going to the UHFS amp, some running speakers directly. But basically there are 12 separate speaker level channels in the UHFS system....to do a proper aftermarket setup retaining (most of) the stock speakers will require at least 9 channels. Im installing a 10 channel DSP processor/amp in order to gain complete control over the system.

Now you could take the route LH has done and just amp the woofers in the car....you could do that with a 5 channel amp, and all the connections are at the external UHFS amp...pretty standard stuff... BUT we don't know for sure what the MCU will do if the amp is not there.....from what I've seen with my LH installs I think it will turn off the low level outputs so you will end up tapping the signal wires behind the MCU anyway. Sooooooo at least for me, if I'm going to go that far I might as well go all the way.

Ive been researching this for a while and have the parts inbound now for my aftermarket install BUT I was an installer for 15 years and have done a number of higher end install in my cars over the years so what is DIY for me is NOT RECOMMENDED for most here. BUT assuming things go well with my install I may make a post about it so that others with some mechanical skill and audio knowledge can follow my lead.....and those without the skill or knowledge can have something to point their installers towards as a target.

Im a couple weeks out from my install right now, waiting for parts. Once Im in there I should have A LOT more concrete info.


For a non UHFS car.....things are a bit simpler as there is no external amp and the front channels are 2 way instead of 3way.....and have passive crossovers.....so in your case you could get away with a much more conventional 5 channel amp install, all the connections tapped into behind the MCU.

There are a TON of if/then/but caveats with all of the above.....and multiple ways to approach upgrading this system, so if you know car audio go ahead and post about it, but if you don't, I would really suggest you consult a professional installer.

 

[JasonA-EV]

I don't have a problem with installing a custom system in my S (I've done it on all my other vehicles) but again I'm only a little 1+ month of ownership on this car so I'm just trying get a grasp on everything before I dive in.

One thing I really want to do is dampen the car even more and it looks like Tesla didn't do much in that dept. I still have 10+ rolls of BrownBread/B-quiet laying around that I plan on using on the car.

Components will be NoS Infinity/Focal's that I still have laying around. LF/Sub I have no idea yet but I'm just trying to layout how to get the audio cleanly out of the main unit on the UHFS system.

That's it.. I guess in the end this harness isn't for me.

 

[jeffb]

Yeah if you have some experience go for it..... talk to muzzman about the wiring diagram he has, you should be able to ID everything you need to tap into on that diagram before you start, then match that against what you see when you pull the screen out. Since you don't have the UHFS it will be pretty straightforward.

 

[coolgj]

I don't have a problem with installing a custom system in my S (I've done it on all my other vehicles) but again I'm only a little 1+ month of ownership on this car so I'm just trying get a grasp on everything before I dive in.

One thing I really want to do is dampen the car even more and it looks like Tesla didn't do much in that dept. I still have 10+ rolls of BrownBread/B-quiet laying around that I plan on using on the car.

Components will be NoS Infinity/Focal's that I still have laying around. LF/Sub I have no idea yet but I'm just trying to layout how to get the audio cleanly out of the main unit on the UHFS system.

That's it.. I guess in the end this harness isn't for me.

Been off TMC for awhile... but if you have UHFS there isn't a clean full output. You will have to sum channels to get full range output. I have two AMPs and DSP installled with some channels sum together.

 

[jeffb]

Yeah, thats what I was thinking.....all the front channels seem to have a crossover on them....so probably will need to sum the front woofers, mids, and tweeters.

OR

Are you SURE the rear door speakers are not being sent a full range signal? Listening to them they sound like they might be.... They dont have the chimes and other noises though so they would still need to be summed with some of the fronts, but Im thinking if they are full range it would be a good starting point.....

 

[coolgj]

Yeah, thats what I was thinking.....all the front channels seem to have a crossover on them....so probably will need to sum the front woofers, mids, and tweeters.

OR

Are you SURE the rear door speakers are not being sent a full range signal? Listening to them they sound like they might be.... They dont have the chimes and other noises though so they would still need to be summed with some of the fronts, but Im thinking if they are full range it would be a good starting point.....

The rear at least when the shop and I testing them was missing some of the low frequency. But they are at the front but the front only has the low frequency. I can connect to the DSP and unsum the rears then check again.

 

[jeffb]

Yeah, sounds right, I went out an stuck my phone next to each speaker with an RTA app running and it confirms that......looks like the fronts are running from roughly 200hz on down and the rears are running 200hz on up.

Did you just sum the front and rear woofer channels or did you get the mids and tweeter channels involved?

If you were able to just sum the front and rear its pretty simple....if you got more channels involved than that things get a bit messy!

Did you tap into the signal before the UHFS amp or after?

 

[coolgj]

Yeah, sounds right, I went out an stuck my phone next to each speaker with an RTA app running and it confirms that......looks like the fronts are running from roughly 200hz on down and the rears are running 200hz on up.

Did you just sum the front and rear woofer channels or did you get the mids and tweeter channels involved?

If you were able to just sum the front and rear its pretty simple....if you got more channels involved than that things get a bit messy!

Did you tap into the signal before the UHFS amp or after?

Yup, I left the fronts alone because of the additional mids and highs speakers but the rears I sum those with the front speakers.

The shop tap into the fronts at the AMP and the rears at the AMP behind the LCD screen. You can get to the wires below the LCD without removing it.

I did not touch the 5 speakers up front as I didn't see a need to change them.

I didn't yet change the speakers in the trunk hatch but I plan on changes those out and connecting it to the DSP.

 

[coolgj]

I have pictures of the installation of you would like to see them.

 

[jeffb]

Yeah, PM sent....

Since you summed the front and rear channels in your DSP.....the parking sensor, starting "bings" and various other noises that come through the stereo, those are mixed in well enough?

 

[JasonA-EV]

all the annoying AP sounds, etc will be mixed in but I don't think there's a way around it. I plan to sum the fronts and rears into the AC unit and then go into their own separate amps. For me I feel the biggest let down on the non UHFS is the speakers and mids/highs. Totally missing.

I'm starting to piece and plan out the system for a "spring install"

 

[Naonak]

Did anyone ever confirm what would happen if the UHFS system was missing the amp? Would there still be signal on those wires that could be directed to another amp or would they need to be tapped behind the MCU?

 

[ebrown7b]

Did anyone ever confirm what would happen if the UHFS system was missing the amp? Would there still be signal on those wires that could be directed to another amp or would they need to be tapped behind the MCU?

I don't know about signals on the wiring harness going to the UHFS amp, but when installing my LH amp, I'm fairly certain that I did have audio in the rest of the car while the amp was disconnected. I inadvertently tested that case by forgetting to connect the harness to the new amp after installing it.

 

[ebrown7b]

I don't know about signals on the wiring harness going to the UHFS amp, but when installing my LH amp, I'm fairly certain that I did have audio in the rest of the car while the amp was disconnected. I inadvertently tested that case by forgetting to connect the harness to the new amp after installing it.

One thing I would love to see is an analysis of the frequency range of the signals sent to each of the speakers. I saw mention in another thread that the fronts are only getting bass frequencies (under 200Hz) and I'd love to get confirmation as to what is being sent to each speaker. If I end up giving up on the LH system, I likely would look to integrate one of the multi-channel DSP systems that can appropriately sum and EQ each signal to (re)produce the full range signals for each of the primary speaker positions (front/rear, left/right).

A wiring harness like you are describing would be great for this integration, though I'm not adverse to tapping the wires as well. That would need to be done for the outputs that don't go through the external amp in any case.

 

[ebrown7b]

One thing I would love to see is an analysis of the frequency range of the signals sent to each of the speakers. I saw mention in another thread that the fronts are only getting bass frequencies (under 200Hz) and I'd love to get confirmation as to what is being sent to each speaker. If I end up giving up on the LH system, I likely would look to integrate one of the multi-channel DSP systems that can appropriately sum and EQ each signal to (re)produce the full range signals for each of the primary speaker positions (front/rear, left/right).

A wiring harness like you are describing would be great for this integration, though I'm not adverse to tapping the wires as well. That would need to be done for the outputs that don't go through the external amp in any case.

I guess I should have re-read this thread first since apparently this *is* the "other" thread where I read about the range limits for the front speaker. In any case, I'd live to see exactly where EQ / crossovers are being applied to the existing signals.