Neumann KH120 II

[LostJack]

It must have been your source material or other problem not related to the monitors. Read the measurements of these by Amir. The harmonic distortion is amazingly low. Completely inaudible.

I tried to play a single pure sinewave at 32 hz and at 60 hz less or more. The distortion was there. And was audible. I use a rme baby face pro fs as audio interface. I didn't have any problem before with my old monitors. (i have also to say that I experienced what I think a bad shielding, interference alredy from 30 cm. Where even a pair of cheaper mackie I use for my TV don't even have that interference problem).

 

[teashea]

I tried to play a single pure sinewave at 32 hz and at 60 hz less or more. The distortion was there. And was audible. I use a rme baby face pro fs as audio interface. I didn't have any problem before with my old monitors.

Did both monitors exhibit this harmonic distortion? Did you measure the harmonic distortion or see it as a waveform? Do you realize that the KH120 II's will not reproduce a 32 hz signal? How did you generate the sinewaves? Did you try a different signal source?

 

[NTK]

I tried to play a single pure sinewave at 32 hz and at 60 hz less or more. The distortion was there. And was audible. I use a rme baby face pro fs as audio interface. I didn't have any problem before with my old monitors. (i have also to say that I experienced what I think a bad shielding, interference alredy from 30 cm. Where even a pair of cheaper mackie I use for my TV don't even have that interference problem).

The KH 120 II is not designed to reproduced 32 Hz. FR drops to -20 dB at 30 Hz.

 

[LostJack]

@teashea Both monitors, initially neumann said that the problem could be the connector of cable (I tryed different cables) and after that the xlr connector of the monitor (both monitor that have the same defect, nah). I noticed the distortion during a mastering session, using my ears. And then I used a normal microphone to see how it was on a frequency analyzer. And was there. I'm not an expert for this kind of stuff so I don't have test material or enofuht knowledge to do that. I know that monitors have limits (is physic), and even this one. But even at 60 hz harmonics where reproduced, I remember that with a sweep test I found even a higher note with that distortion (a lower distortion, but it was there. The frequency was like 1043hz). The sinewave was generated using a plug in.

 

[LostJack]

The KH 120 II is not designed to reproduced 32 Hz. FR drops to -20 dB at 30 Hz.
View attachment 313464

Yes, but why I didn't have this reply from neumann? Also, distorsion was audible even with a 60hz sinewave. And even (as you can read in my last comment) at 1043 hz (way lower, not audible, but existent).

 

[teashea]

It is highly unlikely that both monitors would have a defect. Since the measured/tested harmonic distortion is so far below auditability, It is unlikely the monitors were defective. This means the harmonic distortion was in the signal being inputted to the monitors.

 

[LostJack]

The dsp can cause this kind of problems?

 

[NTK]

Yes, but why I didn't have this reply from neumann? Also, distorsion was audible even with a 60hz sinewave. And even (as you can read in my last comment) at 1043 hz (way lower, not audible, but existent).

Your experience contradicts Amir's measurement [Edit] and his listening test results. Ideally more tests need to be done (and carefully documented) with your setup, but it is not possible now.

 

[teashea]

The dsp can cause this kind of problems?

The dsp actually is designed to reduce the harmonic distortion. It is highly unlikely that both monitors were malfunctioning. What makes more sense is that the signal had harmonic distortion. What was the source of the input sine wave?

 

[LostJack]

Your experience contradicts Amir's measurement [Edit] and his listening test results. Ideally more tests need to be done (and carefully documented) with your setup, but it is not possible now.

Maybe I'll take the time to order a pair and carefully see what's going on. What you suggest to do to test all?

 

[teashea]

Maybe I'll take the time to order a pair and carefully see what's going on. What you suggest to do to test all?

Again, what was the source of the input sine wave?

 

[LostJack]

The dsp actually is designed to reduce the harmonic distortion. It is highly unlikely that both monitors were malfunctioning. What makes more sense is that the signal had harmonic distortion. What was the source of the input sine wave?

I used native ableton oscillator, serum and an online sinewave as test. To be sure that is not the source the problem. Also different xlr cables. And the audio interface is the baby face pro fs. Set up to +4 dbU.

 

[LostJack]

Your experience contradicts Amir's measurement [Edit] and his listening test results. Ideally more tests need to be done (and carefully documented) with your setup, but it is not possible now.

In the listening test actually he said "Throwing my torture track for sub-bass response did result in distorted bass." for that he put high pass filter.

 

[NTK]

Maybe I'll take the time to order a pair and carefully see what's going on. What you suggest to do to test all?

What equipment do you have at your disposal? Do you have a mic and/or audio interface that can be used for measurements?

In the listening test actually he said "Throwing my torture track for sub-bass response did result in distorted bass." for that he put high pass filter.

It is clear from the FR plot that this speaker cannot reproduce sub-bass. But 60 Hz up at moderate volume shouldn't be a problem.

 

[LostJack]

What equipment do you have at your disposal? Do you have a mic and/or audio interface that can be used for measurements?

It is clear from the FR plot that this speaker cannot reproduce sub-bass. But 60 Hz up at moderate volume shouldn't be a problem.

I used a normal mic and my audio interface and a zoom f3. Which mic do you suggest? (pliz, not too expansive).

I listen at low volumes, lower than 80 dB. The distortion (armonics) was still audible for frequencies lower than 100 hz (like 60 hz).

 

[LostJack]

Also, no one commented about the shielding. Is normal that this monitor get interferences from devices at 30/40 cm when a pair of cheap mackie that I use for my tv even at 2 cm of distance doesn't get any interference? (also my older pair of monitor didn't have this problem)

 

[IamJF]

Cause no one had shielding problems with these monitors before, mine are very stable. It's a very curious case you have here - you have problems with these speakers nobody had before and also should not be.

Speaker produce relatively high harmonics at low frequencies and it's possile to hear that with a sine signal. But your other speakers should have the same effect.
Software sine generators are not always clean enough! Check your source signal, RME digicheck could help? Or put the wave signal in your sequencer and do FFT analysis.

Maybe buy a pair of fitting, new cables when you rebuy the speakers. Something like the Sonarworks ref mic should be fine for your measurements and not to expensive. Or you just use the MA-1 which is anyways a recommended addition.

 

[LostJack]

Cause no one had shielding problems with these monitors before, mine are very stable. It's a very curious case you have here - you have problems with these speakers nobody had before and also should not be.

Speaker produce relatively high harmonics at low frequencies and it's possile to hear that with a sine signal. But your other speakers should have the same effect.
Software sine generators are not always clean enough! Check your source signal, RME digicheck could help? Or put the wave signal in your sequencer and do FFT analysis.

Maybe buy a pair of fitting, new cables when you rebuy the speakers. Something like the Sonarworks ref mic should be fine for your measurements and not to expensive. Or you just use the MA-1 which is anyways a recommended addition.

Well, I had that kind of interference problems. And was weird...but both monitor had that shielding problem (maybe one a little bit more than the other). I noticed that because I put my smartphone on the desk. And the monitor started to buzz and to do weird noises, in a very noticeable way. With my old monitors this happen if i put a device really near (like 1 cm), but not at 30/40 cm like the neumann. Even the pair of cheap mackie I use for my tv don't get interferences.

So you say it is normal for this speakers to produce high harmonics at low frequency (like playing a sine at 60 hz)?
I know that the signal is clean because I always used a frequency analyzer in the channel.

I used a fiew brands of cable, one was a brand new cordial with neutrik gold connectors.

 

[BeerBear]

This is from Neumann's measurements (data & diagrams):

Unless I'm misunderstanding that graph, a 30Hz tone should produce audible distortion, even at moderate levels.
At higher levels, it's possible with 60Hz too.

 

[IamJF]

So it is - low frequencies can produce distortion quite a lot but 60Hz must be clean at these levels. That's with ALL speakers in this size.
When they have significant more THD as Mackies at 60Hz there is something wrong.

@LostJack That's the point - these monitors don't do that normally. Not mine, not from the others. So it would be very interesting what the cause was. Did it show it without input cable? With the input shortcutted? Shortcut after the cable? Different interface? Different power socket? Different position in the room? etc...