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M1 iMac buzzing whining noise with low display brightness

I got in touch with Apple Care today and they will look into this. I have a call back next Tuesday. The buzzing on the current one is a lot quieter than on the first one. When I read through all the comments on different sites I think it is a real gamble what kind you get. Could be better or could be worse...

For me I can only hear it in the evening when the brightness is turned down. Most of the time I hear music (which equals in I won't hear the buzzing at all) + the wait time of at least 4-5 weeks without a computer if I start the game again.

I keep you updated what Apple Care will offer me next week.
 
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cookiemonster89 said:
For me I can only hear it in the evening when the brightness is turned down.
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I'm also interested to hear what Apple says. I determined last night that iMac #2 also *does* make the high-pitched whine when the screen is dimmed, but it is only noticeable in a quiet room. It is definitely related to screen brightness, so the PWM theory sounds right. I would certainly not describe it as 'loud', as in that Apple discussion thread. I imagine a lot of users wouldn't notice it and I wonder if some degree of whine is quite widespread or perhaps even included in the 7dB operating sound level Apple advertises. It is no louder than the fan, I would say, but the tinny, whiney high-pitched quality makes it more obtrusive. I'm happy to live with my occasional soft whine at night. I'll probably tune it out when I'm not reading forum threads about it.
 
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Two news websites in Germany picked up the topic and nearly everyone who has one of the M1 iMacs can confirm they also have this issue…
 
I think it's the PWM or coil whine, just like my PS5 (which I hid behind the TV). Probably every M1 iMac does this to some extent, so it's futile to search for perfection. As with any Apple product. We must settle with something "acceptable". Probably you did good exchanging your first unit, but you probably should keep your second
 
I'm a bit disappointed for sure, but it's probably a non issue - the machine is dead silent when I'm working during the day and I'm happy with the performance.

My PS5 on the other hand... it doesn't have coil whine, but a noisy fan. I guess I'm just more aware of sounds electronic devices make because of that right now. Had to order a new fan for it because the sound is THAT bad.
 
Apfelblüte said:
I'm a bit disappointed for sure, but it's probably a non issue - the machine is dead silent when I'm working during the day and I'm happy with the performance.

My PS5 on the other hand... it doesn't have coil whine, but a noisy fan. I guess I'm just more aware of sounds electronic devices make because of that right now. Had to order a new fan for it because the sound is THAT bad.
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I know there are at least 5 different fan designs randomly put on all PS5s at the moment, and the Delta are actually the silent ones, where the Nidec's are more noisy, whereas in the PS4 it was the opposite.. My fan is silent, I just have coil whine on PS5 games, which is not an high pitched sound but more like blowing a raspberry, or a grinding-sound. Luckily even at night I manage to tune it out.
 
I am using my iMac normally and haven't been actively looking for problems, and so far I haven't heard any noises. Admittedly I use my iMac with a relative high brightness and I cannot think of any scenario where I would use it with low brightness. I have also used my iMac with Final Cut Pro doing rendering and the CPU was nowhere to hear. Overall very happy with my iMac.
 
First Feedback: They asked from engineering if I have the newest software installed and wanted to collect some data from the Mac. Because I only had 11.5 and not 11.5.1 installed we needed to find a new appointment. AppleCare said maybe it could be Software related, but from my point of view this is a cheap excuse to put down the case. I don't know how to fix a physical problem with a software update?

I'll keep you updated.
 
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I'm 99,99% sure it can't be software related

I'm also 99,99% sure every M1 iMac has this buzzing to some extent
 
most electronics buzz when outputting a high frequency signal. Be it pwm for screen brightness or radio signals. I just put my Xbox controller up to my ear, and it buzzes. As you lower the brightness, it’s bringing the frequency of the switching close to your hearing range. Heck, even old crt TVs and monitors would wine and change depending on what frame rate was being used. I even calculated the frequency of the circuit, and hence the whine of the coils, of an old tv to 14-15khz. Aprox 500lines per frame times 30 per second.
 
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Everything buzzes, but with different noise levels. I just think the buzzing needs to be bearable or inudible under normal working conditions (like with the iMac at 1m distance from the ears).
 
Because my 14 day return window closes tomorrow I think I will keep the iMac for now. I got a confirmation that I can exchange the iMac at a later stage (e.g. when the shipping times goes down / they maybe found a fix for the problem). ATM the chance of getting the same error and be without a Mac for 5 weeks is not worth the effort for me. A complete return is also out out of the talks because I really like this machine over my old 27" model.

Funny fact now that I listen for these sounds, my work DELL laptop emits sounds which are easily double the sounds the iMacs emits ;-)
 
cookiemonster89 said:
Because my 14 day return window closes tomorrow I think I will keep the iMac for now. I got a confirmation that I can exchange the iMac at a later stage (e.g. when the shipping times goes down / they maybe found a fix for the problem). ATM the chance of getting the same error and be without a Mac for 5 weeks is not worth the effort for me. A complete return is also out out of the talks because I really like this machine over my old 27" model.

Funny fact now that I listen for these sounds, my work DELL laptop emits sounds which are easily double the sounds the iMacs emits ;-)
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You should hear the sounds my old Razer pro 17” made! Dear lord it was like a jet engine taking flight every time I opened an application. I know it’s frustrating, but maybe the next iteration will have better noise cancellation put into the chin? We can only hope
 
Same here! I had my unit replaced and the whining sound is still there, though not so loud as it was in my first iMac M1.
I'm pretty sure it's affecting ALL new iMacs: that's a shame! I tried downloading an app which lets you adjust the screen brightness independently from the Mac Settings. Setting the brightness at 100% in iMac display settings and then dimming the brightness through the app, the whining noise is NOT there, so I think this issue could be solved software-side...
 
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tom_of_finland said:
Same here! I had my unit replaced and the whining sound is still there, though not so loud as it was in my first iMac M1.
I'm pretty sure it's affecting ALL new iMacs: that's a shame! I tried downloading an app which lets you adjust the screen brightness independently from the Mac Settings. Setting the brightness at 100% in iMac display settings and then dimming the brightness through the app, the whining noise is NOT there, so I think this issue could be solved software-side...
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I don't think so, that means you are "darkening" the colors while keeping the backlight brightness at 100%. With the IPS panel this will still be a problem and mess with color accuracy. It's probably in every iMac to some degree and I think that sadly we will need to deal with it. Very bad units will be exchanged but I don't think they'll fix the problem soon. As already said, every single PS5 has a similar coil whine and they're all out there.
 
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coso said:
I don't think so, that means you are "darkening" the colors while keeping the backlight brightness at 100%. With the IPS panel this will still be a problem and mess with color accuracy. It's probably in every iMac to some degree and I think that sadly we will need to deal with it. Very bad units will be exchanged but I don't think they'll fix the problem soon. As already said, every single PS5 has a similar coil whine and they're all out there.
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I think I'm gonna cry.........
p.s Sono italiano come te :)
 
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throwinrocks said:
okay. Because I just found out the base model only has one fan so I'm about to return mine. I'm done with Apple lying to their customers so I'll most likely go back to Android and Windows. I could've purchased a Windows desktop with almost the same specs for half the price.
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Good thing you didn't buy a MacBook Air with no fan, you really would have felt fan envy. I love the sound of an Intel machine fans roaring in the morning, said no one ever. Well maybe gamers staring at their neon glowing towers.
 
I have the same - high pitched noise at all steps of brightness, except four last steps.
I remember that I have had the same kind of noise out of MagSafe power adapter for MBP..
 
tom_of_finland said:
At the end of the month? Why?
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Ordered 23 July with 25 aug - 1 sep delivery window 🥲

By the way an user in the order thread said that the replacement iMac doesn't buzz with low brightness, so maybe there's hope
 
coso said:
Ordered 23 July with 25 aug - 1 sep delivery window 🥲

By the way an user in the order thread said that the replacement iMac doesn't buzz with low brightness, so maybe there's hope
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Really? I suppose most people can't hear the whine, because it's not a real buzz: I'd compare the noise to a very little mosquito behind the display...I can hear it even during daytime, because I already KNOW the whine is gonna be there!
However I read that Apple mostly considers "coil whine" as "expected behavior" (unless it is VERY loud), so I'm not positive about Apple replacing my unit...What a dead luck!
 
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