High pitch reduced by 7-8db

[zabloct]

It was driving me nuts but today I have reduced high pitch noise (2.8khz) by around 7-8db as measured by my phone. The solution was to put mineral wool between drive unit and firewall. Not too elegant solution but can be easily done. If you wan to try it make sure water can still go down from the air filter area down. The amount of wool I used was around 5 square meters in total. I am very pleased with the result. The high pitch is greatly reduced. I can now listen to the music 2 steps lower on the volume. The noise is not completelly gone but its not annoying anymore.
The wool itself is not flammable, is great sound absorber and acts as a protective layer from dirt. The only culprit would be it stops the heat transfer but that should not be a problem as the components are connected through coolant link anyways to transfer the heat to radiators.

I welcome any comments.

Video

 

[drklain]

How are you dealing with it getting wet/retaining water and moisture?

 

[zabloct]

Its hydrophobic material meaning it doesnt absorb water so should be ok, will see with time, just installed it today.

 

[drklain]

Keep us updated on how it goes. My experience with materials like that is that they may not absorb water, but that water tends to collect there and they still get wet/water beads on them. Problem is that water sitting there pressed against other things (metal body, etc.). I am honestly anxious to hear how this goes for you as reducing that wine in the dual-motor Teslas would be a nice thing...

 

[Deisic]

Dang dude. You had to do all that? I'm having the same issue with high pitched noise from drive units at 40-60 mph.

 

[zabloct]

So far so good, not sure about moisture yet but will be installing 360 cameras soon so will inspect it.

 

[polyphonic54]

How is this holding up?

 

[jacie6056]

I am curious about how is that holding up and any link to source the material?
Thanks!

 

[zabloct]

I am curious about how is that holding up and any link to source the material?
Thanks!

Its been ok, havent seen any issues. Its just regular rock wool, same you use for house roof insulation.

 

[dduffey]

I've had high pitch inverter sounds into the cabin (as well as motor/road noise) from the rear seat of my 2018 Tesla Model 3. I used some heat safe wool/barrier and then loaded mass on top of it.

But I am going to redo it and may use your idea as it will be easier to push into crevices and where there is a gap between the battery penthouse and car body.

It's a bit torn up because I was in the process of further troubleshooting and removing this old sound absorbing material.

 

[zabloct]

Good luck, yea with wool you can put it anywhere, can fill every single hole, one advice though, use face mask when doing it, it spreads lots of tiny chunks when you play with it so not too good to breathe it

 

[jacie6056]

Would this one work like you used in the video?
Thermafiber Fire and Sound Guard Unfaced Mineral Wool Insulation
Trying to find one with good quality that can hold up for a long period of time

 

[jacie6056]

It was driving me nuts but today I have reduced high pitch noise (2.8khz) by around 7-8db as measured by my phone. The solution was to put mineral wool between drive unit and firewall. Not too elegant solution but can be easily done. If you wan to try it make sure water can still go down from the air filter area down. The amount of wool I used was around 5 square meters in total. I am very pleased with the result. The high pitch is greatly reduced. I can now listen to the music 2 steps lower on the volume. The noise is not completelly gone but its not annoying anymore.
The wool itself is not flammable, is great sound absorber and acts as a protective layer from dirt. The only culprit would be it stops the heat transfer but that should not be a problem as the components are connected through coolant link anyways to transfer the heat to radiators.

I welcome any comments.

Video

after doing some research, it seems like the material you used is probably fiberglass instead of mineral wool? Again I might be wrong, but the mineral wool I got from Home Depot is pretty loose! Trying to find a material that you used for this application.