Light harmonic amp on MCU2

[verdee]

i have a 2018 100D with MCU2. I bought a LH amp for it, which sounds great but makes a popping noise whenever the system powers up, ie opening the doors. I thought it was a defect with the amp, which was RMA’d and the new one does the same thing. I suspect it has to do with the power saving mode in MCU2, whereas the MCU1 cars had the always connected option, MCU2 doesn’t, so it completely powers stuff down and when it comes back on you get the popping. I wouldn’t get the popping if you started the climate remotely. I’ve actually removed the amp at this point popping was annoying and made the car sound cheap.

I don’t know if anybody else has it installed in a MCU2 car and if you have the same problem or have found a solution. At this point I am considering selling the amp, but wanted get other opinions first.

 

[murphyS90D]

It's a defect in the amp. It should not be producing any audio while it is powering on. There should be a timer in the amp to block audio until power on is complete and stable.

 

[EVortex]

I have MCU2 and purchased a Light Harmonic amp for my Model S. It did originally have some popping on startup and made some unexpected buzzing sounds. The good news is I live in the same town where Light Harmonic is located so I was able to work with them to diagnose the issue and update the amp. Larry Ho and his team are awesome to work with and we worked together to test and tune until the end result was AWESOME! Light Harmonic now knows what to do in their amp to make it work well in an MCU2 car. I really love it in my car. It inspired me to upgrade all speakers and now it sounds even better!

 

[lit af]

Hi. I just upgraded my 2018 p100d model s to mcu2 and since I have that same popping noise as well as my subwoofer is not working. My stock one as well as I swapped in the light harmonic one and it also is not working. Light harmonic never answers the phone. Any suggestions? Thanks guys

Update. Also 3" speakers in hatch also not working. I've done several reboots and still nothing

 

[verdee]

Hi. I just upgraded my 2018 p100d model s to mcu2 and since I have that same popping noise as well as my subwoofer is not working. My stock one as well as I swapped in the light harmonic one and it also is not working. Light harmonic never answers the phone. Any suggestions? Thanks guys

Update. Also 3" speakers in hatch also not working. I've done several reboots and still nothing

Check the fuse?

 

[EVortex]

Hi. I just upgraded my 2018 p100d model s to mcu2 and since I have that same popping noise as well as my subwoofer is not working. My stock one as well as I swapped in the light harmonic one and it also is not working. Light harmonic never answers the phone. Any suggestions? Thanks guys

Update. Also 3" speakers in hatch also not working. I've done several reboots and still nothing

Are you sure your front door speakers are still working? The premium amp only powers the sub, and front door and rear hatch speakers. If none of those are working I would check the fuse for the premium amp. If front door speakers are still working then it would be more of a mystery. I would probably try all of the normal rebooting procedures and maybe even temporarily pull the amp fuse or disconnect 12v. I might also try reseating the wiring harness connector that attaches to the amp. You could also try plugging the wiring harness back into the stock amp if you still have it - that might inform you if it’s an LH amp issue. That’s all I can think of, but admittedly seems like trial and error diagnosis. Let me know what you find out. You might try email for reaching LH. I have not been by their shop in a few months, but did email a couple of months ago.

 

[lit af]

Front speakers are definitely working as is the rear doors and dash speakers. Sub and rear hatch is not.

I'm having trouble finding the fuse box. I followed the directions from light harmonics video and took the whole front apart and do not see it. Mine is a 3/18 build. Not sure if anything has changed.

 

[verdee]

Front speakers are definitely working as is the rear doors and dash speakers. Sub and rear hatch is not.

I'm having trouble finding the fuse box. I followed the directions from light harmonics video and took the whole front apart and do not see it. Mine is a 3/18 build. Not sure if anything has changed.

the fuse for the amp is in the passenger footwell, it’s different for refresh cars

 

[lit af]

Oh dam haha. That makes sense lol. Im.gonna check there. And it says a.30.amp fuse right. It should be

 

[EVortex]

Slot 217, 30 amp micro2 fuse.

 

[lit af]

Crap. Just checked. Fuse is fine. I'm gonna try swapping my oem amp in and see what happens. If it turns out it is the amp I guess I'm screwed because LH has answered any calls or emails yet.

 

[EVortex]

You can try the original amp without having to do a full replacement back into the amp bracket. Remove driver side and front trim to expose the wiring harness “handle” and unlock and disconnect it. Take the old amp and and plug the harness adapter into it and try it out. Might want to leave the fuse out when making the switch and then put it back in for the test.

 

[lit af]

You can try the original amp without having to do a full replacement back into the amp bracket. Remove driver side and front trim to expose the wiring harness “handle” and unlock and disconnect it. Take the old amp and and plug the harness adapter into it and try it out. Might want to leave the fuse out when making the switch and then put it back in for the test

Awesome man thank u. I will try that 2morrow

 

[Xenoilphobe]

I have MCU2 and purchased a Light Harmonic amp for my Model S. It did originally have some popping on startup and made some unexpected buzzing sounds. The good news is I live in the same town where Light Harmonic is located so I was able to work with them to diagnose the issue and update the amp. Larry Ho and his team are awesome to work with and we worked together to test and tune until the end result was AWESOME! Light Harmonic now knows what to do in their amp to make it work well in an MCU2 car. I really love it in my car. It inspired me to upgrade all speakers and now it sounds even better!

Gee I guess I'll drive the 2671 miles out there so they can fix mine, post MCU upgrade....

 

[headcase]

Until I hear of a remedy from Light Harmonic, I'm personally keeping my MCU1 and doing the daughtercard replacement when the time comes. Hearing too many horror stories on the MCU 2 upgrades negatively impacting sound, even without factoring in an aftermarket amp / speakers.

 

[Muzzman1]

Im about to do my MCU2 upgrade but Im looking to see if this is a consistent problem. I find that LightHarmonic is completely unreachable via phone/email/facebook page.
Is it only the pop when power up? Cause I can live with that. I won't be able to live with diminished sounds quality though.

Thanks!

 

[EVortex]

Im about to do my MCU2 upgrade but Im looking to see if this is a consistent problem. I find that LightHarmonic is completely unreachable via phone/email/facebook page.
Is it only the pop when power up? Cause I can live with that. I won't be able to live with diminished sounds quality though.

Thanks!

When I first tested the LH amp without modification, there was a pop on startup and a lighter thump, if you could even call it that, on shutdown. Operation seemed fine. After a couple of test modifications, I heard a buzzing sound during operation. Upon final mods the popping and buzzing were eliminated.

I can’t speak to what others have experienced, but it would be great to hear from multiple sources.

 

[Muzzman1]

When I first tested the LH amp without modification, there was a pop on startup and a lighter thump, if you could even call it that, on shutdown. Operation seemed fine. After a couple of test modifications, I heard a buzzing sound during operation. Upon final mods the popping and buzzing were eliminated.

I can’t speak to what others have experienced, but it would be great to hear from multiple sources.

How the heck did you get a hold of Light Harmonics to discuss this? I've reached out via every method possible....and got crickets.

Im hoping to live with the pop, as long as there is no constant buzz, I will be good.

 

[EVortex]

How the heck did you get a hold of Light Harmonics to discuss this? I've reached out via every method possible....and got crickets.

Im hoping to live with the pop, as long as there is no constant buzz, I will be good.

I live a few miles from their headquarters and visited them in person. That was about a year ago and have not had contact since before Covid so I don’t know what their current status is.

If you go ahead with MCU2 it would be good to know how it turns out. I am sure others would like the feedback.

 

[EVortex]

FYI - My MCU2 was installed new at the factory. Not sure if that matters or not, but thought I would mention it.