[P.K.]

Is anyone besides me bothered by the cabin ultrasonics? It creates a feeling of having your head crushed just a bit- the same feeling you get in a market that has all those motion sensing ultra-sonic devices on. Is it a byproduct of the controller frequency or the interior motion sensor that can't be turned off without locking the car?

[JasH]

Are you Batman?


Seriously, you can hear ULTRAsonics?

[fishpond]

Originally Posted by P.K.

Is anyone besides me bothered by the cabin ultrasonics? It creates a feeling of having your head crushed just a bit- the same feeling you get in a market that has all those motion sensing ultra-sonic devices on. Is it a byproduct of the controller frequency or the interior motion sensor that can't be turned off without locking the car?

I've not experienced any issues and to be honest I have no experience of any of the symptoms you are describing

[Maxxsirrah]

Been watching too much Better Call Saul i think

[Aye-eight]

Originally Posted by P.K.

Is anyone besides me bothered by the cabin ultrasonics? It creates a feeling of having your head crushed just a bit- the same feeling you get in a market that has all those motion sensing ultra-sonic devices on. Is it a byproduct of the controller frequency or the interior motion sensor that can't be turned off without locking the car?

I don’t get that sensation - in the car, a supermarket, or elsewhere. And I thought my ears are fairly sensitive, as I can hear anti-rodent devices. Can you hear a dog whistle?

And I would think the interior motion sensor gets turned off when the car is unlocked and / or in motion.

[Coastali8]

That explains it. Ultrasonics. Just a ringing sound in my ears. Never goes away. Who knew my hearing was that good.

[P.K.]

Well at least there is one more "sensitive" person out there. You aren't talking about a permanent as in NEVER goes away are you? My post doesn't use the word "hearing" I am talking about the in car discomfort that I believe is caused by high frequency vibrations.
Using the word -ultrasonic was a mistake I think.
Question is- what is generating it and even more to the point, can it be reduced by cancelling technologies or filters? Even Batman can hear the controller "wind" up and go beyond hearing frequencies. I am now into my 3rd month with this great car and haven't yet done enough research to find out if it is speed related or power related or sensor related.
My engineers are going to be setting up a frequency analyzer so I can some real answers.
Seems not much help here....

[MichaelJohn]

Originally Posted by P.K.

Seems not much help here....

When you talk about your head being crushed by ultrasonics you are bound to get some colorful responses. Plus, I doubt that anyone here has experienced anything like what you describe but I suppose it is worth asking the question.

It couldn't be something simple like the whine of the electric motor, could it?

[P.K.]

I obviously need to be far less descriptive and use shorter sentences. One always expects a number of jump in with a wise crack responses but then I was hoping to seek out anyone with a genuine curiosity or similar experience. "ultra- sonic" motion sensing has largely been replaced by infrared technology so this may have been a poor reference. My initial suspicion
was the AC controller that has a pitch related to the motor speed. That is the subtle rising whine that is heard as the speed increases. It continues well beyond that audible range. Thanks for the response.

[Louv]

The only uncomfortable sensation I get in the car is when one window is down, but the other isn't, and I'm driving at more than 25 mph. There's an odd reverb caused by the aerodynamics. (Rather common in the BMWs I've owned) Fixed by lowering the passenger window as well.

[P.K.]

Our research has verified the source of the ultrasonics. If you gently remove the facia from the overhead interior lighting panel there is an array of three transducers- We made removable sound absorbing pads to attach to the transducers as an initial test. This made a significant change and has made driving much more comfortable. I would disconnect them but at this point our non destructive fix has addressed the issue. I can only assume that ultrasonic hearing is a fringe situation overlooked by the security design.

[Epirali]

You can't hear ultrasonics, but if they interfere right they will create audible tones. These can be heard or "felt." I am an audio professional and I have not heard any tones, sonic or ultrasonics in neither in my i8 coupe (2015) nor in the 2019 Roadster. And believe me when I say I am VERY sensitive to any sound by profession and nature and my hearing still goes out to 15K.

[P.K.]

Call it ultrasonic hearing or call it what ever you want. The facts are these: I "felt" a discomfort and was seeking similar experience- none apparently. There are three ultrasonic transceivers in the cabin as part of the antitheft system. I covered the transducers with sound absorbing material. The "feeling" has greatly diminished. Done! Incidentally, as a technical theatre instructor, I taught a number of audio professionals - they now work in theatres, live performance, recording, and sound re-enforcement design. I have a state of the art theatre and recording facility in my home so I too have real experience although these old and abused ears have lost their edge to the young non rock and roll set.

[noit]

I totally agree with PK. I am sensitive to active noise cancellation and a lot of cars are using it now. I had to remove the module in my Acura RDX to disable it (and it was 'fixed').

With the i8, I rented one for 24 hours before I bought it. I drove it for 5 hours straight in sport mode and by the end felt the pressure described. I eliminated it from my shopping list for months because of it.

I looked into it and there is active noise cancellation used in the car as part of active sound design. After buying it, I've rarely used sport mode and haven't had the issue-- maybe it's more pronounced when everything is louder in sport. I asked the BMW dealership if it can be coded out and after escalating it from my local Bay Area dealership to New Jersey to Germany, they ghosted and I never heard back. I assume it's not easy/possible.

Anyway just wanted to agree with your sentiments and it's definitely not wind buffeting like some other suggested.

[JasH]

Where is your source that i8 has active noise cancellation?

If it had the technology, BMW would have advertised the feature. So I cannot believe that.

[noit]

Originally Posted by JasH

Where is your source that i8 has active noise cancellation?

If it had the technology, BMW would have advertised the feature. So I cannot believe that.

I can't seem to find the source-- LOL I know, suspicious, but it was a single line in an article somewhere.

But you are correct-- perhaps my statement of active noise cancellation was a little strong since that implies it's at all frequencies for road noise etc. Specifically, the description I read said that it cancelled out some undesirable frequencies of the 3 cylinder and augmented some other frequencies to get a smoother sound. Same cancellation idea, but applied much more focused-- to maybe only a few frequencies.

[JasH]

Most likely simply referring to the enhanced sound inside, using the speakers. It's pretty good in Sport mode to be fair.