Well it turns out I can't use my Digidesign 003 digitizer on OS X Big Sur (Avid hasn't updated the driver in years), so my hopes for a DAW in my car using studio-quality microphones have been dashed. But I don't think I need them anyway, because...
...I just did a different analysis and got very interesting results. I drove around at 15-20 MPH in my wife's Model Y and then my Model 3 and recorded the ambient noise on an iPhone 8 placed on the passenger seat, using some music recording software (Music Memos) that does not use any auto gain / compression (so comparisons are apples-to-apples). I then found a representative section of audio that was just the cabin sound (no other cars/horns/sirens) and looked at the spectrum for both cars.
Model 3:
View attachment 622255
Model Y:
View attachment 622256
(I recommended you download the full images and look at them in a viewer that lets you instantly swap between two images with a keystroke (
IrfanView is fantastic image viewing software if you've got a Windows system or are using wine on linux or OS X).
When you do an A/B comparison, you can see that while the noise of both cars from 20Hz to 20kHz has a different shape, the overall energy is similar. I would be hard pressed, looking at these images, to say one car is louder than the other.
However in the low frequencies, you can see that the peak moves from around 50-60Hz for the Model 3 to around 30-40Hz for the Model Y. And the energy around 20Hz (where you definitely feel it instead of hear it) is about 15dB louder in the Y. There is a lot of energy in that <30Hz infrasound region.
So at this point, my thinking that while the overall noise in the Model Y's cabin is similar to the Model 3's, the Model Y cabin/frame's resonant frequency is about 30-40Hz, with significant energy around 20Hz compared to the Model 3. Loud sounds around these infrasonic frequencies make some people uncomfortable. Mythbusters explored it
here (Jamie's conclusion: "It's sort of anxiety-producing...it's unnerving).
This guy talks about it at length, and includes links to
20Hz and
19Hz tones that are, well, anxiety-producing and unnerving (you should listen to them on good headphones or a subwoofer, and start quietly and ramp up the sound so you don't damage your gear or your nerves). It's surprising what a difference 1Hz makes!
And since my and presumably many of your Model Ys are putting out a fairly constant mix of sounds at 19Hz, 20Hz, and thereabouts, it's not surprising that some people are un-nerved by, anxious from, and/or unhappy with the sound/feel in the cabin of their Model Y when driving.
My previous slide show was talking about the compressor making noise around 30Hz. Just to be clear, I'm not saying the compressor is actually generating 30Hz noise (possible, though) - it may have been generating periodic impulses that shake the car like a hammer striking a bell, causing it to vibrate at its resonant frequency of 30Hz. And if there was a mount loose or missing on that compressor, the hammer would effectively be striking harder. So I think this is how the compressor can contribute to this phenomenon.
I don't think it's always easy to change the resonant frequency of such a big/heavy structure, but it sounds like there might be ways to mitigate it (a lot of people say adjusting the stoppers on the trunk helps). Hopefully we (or better yet, Tesla) will get it all figured out soon.
I'm going to the service center tomorrow - will let you all know what they say about it.
Finally, here are big copies of the photos in case some people can't use the thumbnails:
Model 3:
View attachment 622255
Model Y:
View attachment 622256
