Strange issue with Neumann KH 750

[KabukiHakase]

Hello all,

This is my first post here, so please let me know if I am posting in the wrong forum.

Last month, I got a Neumann KH 750 DSP + MA-1 calibration microphone. I am using the KH 750 (and calibration) with my Genelec 8020D, and thus far, the whole system has been working great. I've never experienced time alignment with a sub before, so the difference is night and day. The room EQ also helped too, and sounds much better than any plugin I've used so far.

All this being said, I'm now a bit worried about the reliability of this unit. Today while playing some music (Apple music via the web browser) I noticed that the low end had suddenly vanished, and it sounded like only my Genelecs were active. Sure enough, I looked behind the sub and found that the power LED was a solid amber color, which according to the manual, indicates a firmware update in progress. I thought this was pretty damn bizarre, considering that I had no Neumann software open and haven't touched the unit at all since doing the initial MA-1 calibration. It is worth noting that I leave the unit connected to my PC via ethernet at all times, in case I want to make changes or switch calibration profiles.

In good faith, I waited for this light to change color and the sub to start working again, but nothing ever happened. After a few minutes I did a power cycle using the switch on the back panel, and now it's working again as expected. Has anyone run into this, or a similar problem, with Neumann DSP enabled products? To me this seems like a bug, since I highly doubt the sub would decide to upgrade its own firmware, with NO Neumann software open, right in the middle of audio playback. I called Sweetwater (since Neumann support is worthless and they don't reply) and they said if the issue happens again they would send me a replacement unit.

Any similar stories? Any feedback is much appreciated. I'm attaching a picture of the state the sub was in when the issue occurred.
Thank you!

 

[HarmonicTHD]

Hello all,

This is my first post here, so please let me know if I am posting in the wrong forum.

Last month, I got a Neumann KH 750 DSP + MA-1 calibration microphone. I am using the KH 750 (and calibration) with my Genelec 8020D, and thus far, the whole system has been working great. I've never experienced time alignment with a sub before, so the difference is night and day. The room EQ also helped too, and sounds much better than any plugin I've used so far.

All this being said, I'm now a bit worried about the reliability of this unit. Today while playing some music (Apple music via the web browser) I noticed that the low end had suddenly vanished, and it sounded like only my Genelecs were active. Sure enough, I looked behind the sub and found that the power LED was a solid amber color, which according to the manual, indicates a firmware update in progress. I thought this was pretty damn bizarre, considering that I had no Neumann software open and haven't touched the unit at all since doing the initial MA-1 calibration. It is worth noting that I leave the unit connected to my PC via ethernet at all times, in case I want to make changes or switch calibration profiles.

In good faith, I waited for this light to change color and the sub to start working again, but nothing ever happened. After a few minutes I did a power cycle using the switch on the back panel, and now it's working again as expected. Has anyone run into this, or a similar problem, with Neumann DSP enabled products? To me this seems like a bug, since I highly doubt the sub would decide to upgrade its own firmware, with NO Neumann software open, right in the middle of audio playback. I called Sweetwater (since Neumann support is worthless and they don't reply) and they said if the issue happens again they would send me a replacement unit.

Any similar stories? Any feedback is much appreciated. I'm attaching a picture of the state the sub was in when the issue occurred.
Thank you!

View attachment 343151

Isn’t the answer to your question written right underneath the LED?

 

[custom]

I haven't had this problem yet and the LED also lights up amber when sub ist muted.

 

[KabukiHakase]

Isn’t the answer to your question written right underneath the LED?

Red means protection is active (or the sub is booting up) which is a different status. The LED was amber colored, as pictured in my post. According to the manual, amber indicates a firmware update.

From the manual:

 

[KabukiHakase]

I haven't had this problem yet and the LED also lights up amber when sub ist muted.

Very interesting...
I don't use the Neumann control app, so I have no way of muting the sub. If the sub was in fact muted, then it basically muted itself, which is also not good. There's no reason it should be doing this under normal circumstances.

Thank you for the info!

 

[unpluggged]

Red means protection is active (or the sub is booting up)

Are you sure it's indeed amber?

 

[KabukiHakase]

Are you sure it's indeed amber?

View attachment 343180

I am 100% positive. I could even see the component colors being mixed inside the LED (red and green LEDs active at the same time mixed together to create orange/amber)
When the LED is red, it is solid red. No colors are being mixed and only one LED is active inside the unit.

Here is a picture I took just now while the sub is powering on. Compare this to the photo in my original post.

 

[custom]

Very interesting...
I don't use the Neumann control app, so I have no way of muting the sub. If the sub was in fact muted, then it basically muted itself, which is also not good. There's no reason it should be doing this under normal circumstances.

Thank you for the info!

MA 1 mutes the sub during measurements of the monitor speakers. Just have a look on the LED.

 

[KabukiHakase]

MA 1 mutes the sub during measurements of the monitor speakers. Just have a look on the LED.

Right, but I was not performing any measurements when this happened. I was playing music and no Neumann software was open on my PC.

 

[KabukiHakase]

I got a reply from Neumann! Nice people too, and they apologized for the delay.
In case anyone else finds this thread and has a similar issue, here is the reply I received:

Regarding the LED indicator in amber/yellow colour. I guess you have the KH750 DSP AES Version?

When the INPUT SELECT switch is set to AES67: Normally the POWER ON LED lights up red for 5 seconds and then amber/yellow for 2 minutes. During this time, the subwoofer is muted. The POWER ON LED then lights up green.

In fact, this LED is also used for firmware and lights up amber/yellow during this time. However, it also lights up amber/yellow for approx. 2 minutes while the subwoofer is logging into the network.

In my case, I don't actually have the AES version of this sub, and I confirmed this by the lack of an INPUT SELECT switch on the back of my unit.
However, the last line in his reply is key. I suspect the sub was trying to communicate with my PC via ethernet and somehow became confused.
Most users probably have this sub connected to a network switch or router. That isn't really practical for my setup, hence why I am using one of the two gigabit ports on my motherboard. Maybe this is an unreliable configuration in the long-term? No way to say for sure, but the issue has not returned (fingers crossed!)

Hope this helps someone else. If I get more information from Neumann, I am happy to share.