Neumann KH 80 DSP - vibrating zzz-noise

[diwic]

Long story short; two out of three speakers I've ordered had a vibrating zzz-noise when playing a sine wave of 450-550 Hz at medium-high volume. The exact frequency seems to vary a bit between tests.

The vibrating zzz-noise, or possibly coil whine, or something like that, comes from the speaker's back side. In some cases I was able to reduce the noise by holding a finger on the XLR contact, thus absorbing the vibration. (I've tried switching XLR cable which did not make a difference.)

So I started by ordering two speakers where one had this problem, the other one did not. So I returned the speaker with the problem and got a new one which also had this problem.

So I'm just checking with the rest of you if this is something you have heard of or encountered? Because either:

1) There is a systematic failure in design or production of the Neumann KH 80 DSP, in which case we should have heard of more of this, but I have not found any other reports of this so far.

2) I've been extremely unlucky, in which case I could just order a fourth speaker and it should work okay

3) The speakers are fine and something else is wrong with my setup. But I've tried my best to rule this out: First, I've tried different speaker locations, and that can cause the resonance frequency to change a bit, but still I can hear that the sound in fact comes from the speaker's back side. Second, one of the speakers does not have this problem.

Let me know what you think. Thanks in advance!

 

[abdo123]

coil whine is coil whine. if that's the case then just replace the speakers if they're bothering you..

I don't see how your setup would influence the issue if the noise is not coming out of drivers.

 

[q3cpma]

Contact Neumann, since you have two samples having the same problem.

 

[diwic]

Contact Neumann, since you have two samples having the same problem.

Thanks for the reply! Would that be the distributor in my country or is there a better way to (hopefully) get to the tech people who are likely to know this first hand?

 

[0321]

related or not, this reminded me of some stuff I've seen before:

1)
https://www.forum.rme-audio.de/viewtopic.php?id=28874
'Thirdly, the backplate resonates quite audibly at about 270 Hz even at moderate output levels'
'I went to the store where I bought the KH80 to compare to their exhibition model which had the exact same issue and the store personal also mentioned that another costumer had returned a pair of KH80 for the same reason.'

2)
https://gearspace.com/board/product...h-80-dsp-raises-standard-monitor-sound-5.html
'Mine were ordered and one of them came with with extreme insulation problems, and with lot of acoustic vibration because the rear part of the speaker is attached by plastic clips.

And these tiny clips that are responsible to push the backplate on the speaker enclosure were broken. Be very careful if you ever have to open the speaker. If you do so and one of these clips break, there's no way ever of closing the speaker correctly again'

 

[diwic]

related or not, this reminded me of some stuff I've seen before:

1)
https://www.forum.rme-audio.de/viewtopic.php?id=28874
'Thirdly, the backplate resonates quite audibly at about 270 Hz even at moderate output levels'
'I went to the store where I bought the KH80 to compare to their exhibition model which had the exact same issue and the store personal also mentioned that another costumer had returned a pair of KH80 for the same reason.'

Thanks. So it's not just me then, I thought I was going crazy. Not sure why mine resonated at a different frequency than theirs but still it seems to be a similar issue.

 

[diwic]

Thanks for the reply! Would that be the distributor in my country or is there a better way to (hopefully) get to the tech people who are likely to know this first hand?

I did ask and just recently got a reply from the representative in my country. The email said that the person had not heard about this issue before.

 

[Kachda]

Only thing to do is to send to @amirm for review

 

[diwic]

Status update: Fourth speaker has now arrived. It does not have the "resonating backplate" / "coil whine" issue.

Rarely I can hear something resonating, but at this point it could just as well be something in the room.

 

[Lilith]

I had exactly the same thing 3 years ago with one KH80. It was sent to Sennheiser and came back again with the remark that it's fine.

 

[Fabiano Oliveira Mix]

I’ve already bought a second hands pair and one of them has this “issue” I don’t know what to do. Around 250 in a medium/high level makes a horrible sound. The other monitor makes that sound too when te level is too high. Any solution? Is an easy issue to fix?

 

[Lilith]

I’ve already bought a second hands pair and one of them has this “issue” I don’t know what to do. Around 250 in a medium/high level makes a horrible sound. The other monitor makes that sound too when te level is too high. Any solution? Is an easy issue to fix?

Does this happen with music or with Sine tones only? If the latter don't think about it.

 

[Fabiano Oliveira Mix]

Does this happen with music or with Sine tones only? If the latter don't think about it.

When I’m recording or mixing any percussion instrument with a great energy in that region or an acoustic guitar without Eq for example. In music it happens just when I play in higher levels ( I rarely do that ).

 

[Lilith]

When I’m recording or mixing any percussion instrument with a great energy in that region or an acoustic guitar without Eq for example. In music it happens just when I play in higher levels ( I rarely do that ).

Do you still have warranty? The speaker is fine it is presumably only the board that hit the housing on the back. You can try pressing on different positions on the back until the sound disappears to see where exactly it comes from.

 

[Fabiano Oliveira Mix]

Do you still have warranty? The speaker is fine it is presumably only the board that hit the housing on the back. You can try pressing on different positions on the back until the sound disappears to see where exactly it comes from.

Thanks for that I’ll try this. I haven’t warranty and I don’t know if has Neumann support in Brazil.

 

[Fabiano Oliveira Mix]

Look the sound that do when I put the 200hz and increase de volume.

https://drive.google.com/file/d/1S7SOZHCuURRb2WDAlEUNsQC4plXbl9MS/view?usp=drivesdk

 

[Lilith]

Look the sound that do when I put the 200hz and increase de volume.

https://drive.google.com/file/d/1S7SOZHCuURRb2WDAlEUNsQC4plXbl9MS/view?usp=drivesdk

Oh... That 's not acceptable. Does it come from the back or the front? I would send them to Sennheiser after they estimated the costs for repair.

You could call them

Sennheiser — fones de ouvido, microfones e sistemas sem fio - Sennheiser

Por mais de 75 anos, nossos produtos vêm com uma missão integrada: manter-se fiel ao som e à alma que o artista deu à sua música.

pt-br.sennheiser.com

 

[Fabiano Oliveira Mix]

Oh... That 's not acceptable. Does it come from the back or the front? I would send them to Sennheiser after they estimated the costs for repair.

You could call them

Sennheiser — fones de ouvido, microfones e sistemas sem fio - Sennheiser

Por mais de 75 anos, nossos produtos vêm com uma missão integrada: manter-se fiel ao som e à alma que o artista deu à sua música.

pt-br.sennheiser.com

Comes from the front. I’m waiting for the sennheiser’s answer.

 

[Lilith]

Comes from the front. I’m waiting for the sennheiser’s answer.

Probably the woofer grid?

 

[Fabiano Oliveira Mix]

Probably the woofer grid?

I’ve tried to hold with my hands because I thought that was too but nothing happened. I gave back the Neumanns and I imported a new pair from sennheiser BR.