High-Pitched Motor Noise

  • Thread starter Thread starter SeanH
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I can't hear anything out of the norm with your sound byte. Have a look and listen to SeanH's video linked to in post number 13 of this thread. The sound in that video is exactly the same as what I am experiencing.

I have a feeling it is a poorly assembled (loose) winding in the motor.
 
Yeah, I've listened to that a few times. Outside of the VESS I could not guess what that whistling noise is. 9700 and 17,700 Hz seem to be the relevant peaks, as I know the VESS rolls off after 6 or 7 kHz. Noting that it's higher on acceleration it's very likely current-related. I very much doubt this is the result of a "loose winding" for several reasons but it's likely related to semiconductor switching frequency(ies) in some way, as harmonics of course since the fundamentals are likely higher. I'm certain I could not personally hear the noises if they were present on my car. When I get an opportunity I'll get one of my younger relatives to have a listen.

upload_2019-6-23_8-56-42.webp
 
KiwiME said:
Here's another with sound file. Not sure why the roll-off under 8kHz, could be the mic. Sorry about the damn birds chipping, I thought it was a quiet hill.

View attachment 5123
Click to expand...

Some advice when recording weird car sounds. I recorded my Niro EV noise issues inside a large underground parking structure when it was mostly empty. Not only did it remove any external sounds, the enclosed walls amplified the sound so it was easier to pickup with my smartphone mic.
 
I can hear the same noise on my kona at 800 km on the odometer.

I don't know if this was audible before since it's the first time today that i drive with windows open in town.

I can't hear it with windows closed or if I'm not driving next to a wall or parked cars.

Yes, it's a bit annoying but not a reason not to buy the car. And if all new cars have this noise, i doubt it's a defect...

I'm an electrical engineer so I'm used to all sorts of weird noises coming out of motors driven by VFDs. It's probably just harmonics.

I'm also going slightly deaf and nearing 40 but i can definitely hear the noise. It's not just young people.
 
OK, I'm having too much fun with this but it's a rainy Sunday. Here's the SeanH audio as an MP3 with the VESS filtered out. Afflicted owners, is this what you're hearing?
Just to add that looking at Siemens EV motor controllers, the working frequency quoted is 2-12 kHz, much lower than I thought.
 

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KiwiME said:
OK, I'm having too much fun with this but it's a rainy Sunday. Here's the SeanH audio as an MP3 with the VESS filtered out. Afflicted owners, is this what you're hearing?
Just to add that looking at Siemens EV motor controllers, the working frequency quoted is 2-12 kHz, much lower than I thought.
Click to expand...

Great job filtering that out. It sure is a nasty sound without the VESS. Makes me wonder if the VESS sound was chosen to cover this up. The bad news is, that is what I am hearing.
 
EnerG said:
Great job filtering that out. It sure is a nasty sound without the VESS. Makes me wonder if the VESS sound was chosen to cover this up. The bad news is, that is what I am hearing.
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Great, so now we have to mute VESS as well as introduce some form of active noise reduction for that band of fr to have a quiet ride :rolleyes:
Why didn't Hyundai do this already?
Wonder what the exact fr is to cancel?
 
There has only been one person to successfully capture the noise. The mp3 file above is not at all the sound. It is VERY noticeable and sounds wrong and abnormal. There is absolutely no confusing it with any “normal” electric car sound. Any person I have in the car with me notices it within about 30 seconds, if we’re driving with the windows down.

It’s so frustrating trying to explain something that is nearly impossible to capture on audio recording. I can’t recall the users name, but he had his car lifted on a jack and had a camera by the motor under the car - you could hear it perfectly. Literally everyone else seems to be describing the normal VESS (100% not the sound) or the cool space ship noise when quickly accelerating (again, 100% not the sound) The only way I’ve been able to explain this to anyone and seen are sort of comprehension on their faces is by telling them it sounds like the high-pitched noise you hear when you have old rusty brakes and are in desperate need of a brake job.

I really, really hope for the sake of my sanity that someone figures it out or Hyundai issues some sort of recall. I have not heard it on any Ioniq’s or Soul EV’s which are essentially the same car.


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MGrognon said:
So just came back from dealership... Did a road test, guy couldn't hear what I was talking about. When we ran next to buildings he understood/heard what I was talking about but considered this wasn't out of the ordinary / abnormal. I asked to test out a demo Kona EV they had on hand (Ultimate ; mine is a preferrred trim) = 3 seconds in at 10 mph/20kmh or so I heard the same exact noise. Another Kona was leaving the dealership as I was walking out of the Kona ; same sound. There was an Ioniq driving in ; I didn't hear a similar sound on the Ioniq but it was brief and outside with road noises nearby, so hard to say.

It would seem this is an issue on all Konas (at least the 2 I saw / heard today and mine) but it would also seem that to Hyundai ; this is not an issue. 2 different people listened to the noise I was pointing out ; interestingly enough the older man could not hear it at all and genuinely thought I was crazy I think. The other (younger) did hear it, but faintly / didn't see this as a problem, but they couldn't point out what exactly this was / why it made that sound ... There may actually be a component where some people just don't hear (or care about?) these type of frequencies, whereas for others it's annoying as hell. I wouldn't recommend the Kona to family / friends specifically because of this ; that's how much it annoys me.

I plan on sending a formal letter to Hyundai Canada ; I know this may sound trivial but if there is anything they can do to resolve (or attenuate) this somehow, I'd really like them to try. I love everything about the Kona except soundproofing (pretty loud in there at 50+ mph / 90+ kmh) and that annoying hissing.
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If you have a contact for Hyundai, could you pass it on. I’ve been trying, unsuccessfully to find a phone number or email address.


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EnerG said:
The bad news is, that is what I am hearing.
Click to expand...
I had another poke around the audio from the SeanH video and there are four distinct regions of noise:
A) below 200 Hz, presumably the rumble of the mechanicals
B) the VESS which ranges from 200 to 7,000 Hz which has an additional unidentified component perhaps related to C and D
C) lower 'switching' (for lack of a better term) noise centered around 9,700 Hz
D) higher frequency 'switching' noise centered around 17.6 kHz, noting that the mic appears to roll off after 18.5 kHz

The mp3 I provided earlier is of C and D, noting that I can only hear D separately if I use high-spec earphones and turn up the volume.
Looking at B again, check out the MP3 below with a high-pass filter above 2,400 Hz instead of 7,000. That leaves much of the unidentified component and higher 'switching' frequencies with the VESS less intrusive.
 

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KiwiME said:
I had another poke around the audio from the SeanH video and there are four distinct regions of noise:
A) below 200 Hz, presumably the rumble of the mechanicals
B) the VESS which ranges from 200 to 7,000 Hz which has an additional unidentified component perhaps related to C and D
C) lower 'switching' (for lack of a better term) noise centered around 9,700 Hz
D) higher frequency 'switching' noise centered around 17.6 kHz, noting that the mic appears to roll off after 18.5 kHz

The mp3 I provided earlier is of C and D, noting that I can only hear D separately if I use high-spec earphones and turn up the volume.
Looking at B again, check out the MP3 below with a high-pass filter above 2,400 Hz instead of 7,000. That leaves much of the unidentified component and higher 'switching' frequencies with the VESS less intrusive.
Click to expand...

This is so cool. I identified 3 categories at the time -- I probably grouped C and D.
I'm sorry I haven't gotten it back up on the lift and done the recording with something better than an iPhone. It is on my to-do, but I have to rebuild my favors with the techs at work ;-)
For that test I will also try to unplug the VESS.
The general consensus among my EE buddies is that it is switching noise either in the inverter or in the motor itself. The real question is whether it is in 100% of Konas. I would think that it would've been noticed in the many reviews that existed for a year before I bought mine (in the US), but none mention it. Do the NA versions have different electronics? I wouldn't think so...
 
I have had my Kona now for just under 2 months (3500 kms), but have not noticed any unusual sounds, just the VESS with reverse and low speed forward. The only thing I do notice is a lot of road noise (maybe wind, too?) at hwy speeds.

Having said we normally drive with the windows closed, and use climate control. Although, have tried turning them down a couple times to see if I can hear what you guys have been talking about. I have asked my wife, too, and she doesn't hear anything unusual either.
 
R P said:
I have had my Kona now for just under 2 months (3500 kms), but have not noticed any unusual sounds, just the VESS with reverse and low speed forward. The only thing I do notice is a lot of road noise (maybe wind, too?) at hwy speeds.

Having said we normally drive with the windows closed, and use climate control. Although, have tried turning them down a couple times to see if I can hear what you guys have been talking about. I have asked my wife, too, and she doesn't hear anything unusual either.
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Try to go drive by her at ~10 mph. You have to either be on the accelerator or regening (not coasting). I can make the noise by tapping the accelerator or the regen part of the brake.
 
It is very weird. I am pretty sure mine doesn't do it. I try to listen once in a while as well but haven't noticed any noise like that. [emoji1696]

Sent from my moto x4 using Tapatalk
 
Ive been in underground parking lots and driven thru confined tim hortons drive thrus and only thing i hear is the VESS. I drive all the time in hotter weather with all the windows down and still dont hear anything odd.
I also have good ole army hearing loss, so maybe that helps. Lol
 
Was out again today, and rolled windows down on both sides as I was driving past buildings going slow. VESS was on to about 15 or 20 kph, and then totally quiet after that. Tried braking and acceleration a bit at low speeds, but nothing. So I have no idea what you guys are talking about.
 
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