Neumann KH120 - tweeter issue or normal unit difference?

[Lilith]

I did some sweeps on Monday at the listening position and varied the position and angle of the mic. This peak is present in all measurments while the other speaker measures flat in that region.

This is the measurement were both speakers were at the same position

220604_003_sameposition_2.mdat - Shared with pCloud

Keep all your files safe, access them on any device you own and share with just the right people. Create a free pCloud account!

e1.pcloud.link

 

[HarmonicTHD]

I did some sweeps on Monday at the listening position and varied the position and angle of the mic. This peak is present in all measurments while the other speaker measures flat in that region.

This is the measurement were both speakers were at the same position

220604_003_sameposition_2.mdat - Shared with pCloud

Keep all your files safe, access them on any device you own and share with just the right people. Create a free pCloud account!

e1.pcloud.link

I would try the following just to exclude the room as much as possible and determine if one of the tweeters is really that far off.

Only measure one speaker at a certain position maybe at a distance of one meter with the mic pointing at the speaker (use the 0deg calib file). Than simply exchanging the speakers and measure the other at the very same position as the first. If they still deviate, then return them. If not, it is the room and you EQ the hump.

 

[Lilith]

I would try the following just to exclude the room as much as possible and determine if one of the tweeters is really that far off.

Only measure one speaker at a certain position maybe at a distance of one meter with the mic pointing at the speaker (use the 0deg calib file). Than simply exchanging the speakers and measure the other at the very same position as the first. If they still deviate, then return them. If not, it is the room and you EQ the hump.

I did this already,, see the rew file from above. Distance was 10cm to the tweeter. I slightly varied the mic position from measurement to measurement. But I measure the same peak at larger distances also. It's the speaker for sure. But does it matter at that frequency?

And what if the next speakers have any other issue? Should I go for Kali instead and live with some minor flaws then? A bit more bass would be nice to have.

 

[ernestcarl]

@Lilith

Such a minor deviation requires only two PEQs to "fix"

PK Fc 15500 Hz Gain -2.50 dB Q 3.000
PK Fc 12200 Hz Gain 1.20 dB Q 2.000

This will reduce the resonance a tad -- whether it's practically audible or not -- I doubt. Then again, personally, I can barely hear in that range, if at all.

 

[Lilith]

I also wrote to Sennheiser and a I'm waiting for reply.
I'm doing automatic room correction and will check if there's a difference for left and right in that range.

 

[LTig]

What about doing a MMM (Moving Mic Measurement) using pink noise at the listening position, with averaging in REW?

 

[Lilith]

What about doing a MMM (Moving Mic Measurement) using pink noise at the listening position, with averaging in REW?

This I can do. Have to check this works though...

 

[Lilith]

Somewhere else people told me I'm crazy when sending them back because of this. Obviously I'm not that crazy

 

[Lilith]

That's the measurement with periodic pink noise and moving the mic at the listening position for both speakers. SPL was around ~78 dB(C) at listening position.

Repeated it once more:

 

[wwenze]

Yea... I would return the tweeter

Funnily the good speaker plot seems to suggest this also occurs there except at a reduced intensity. Something is supposed to damp the resonance but it's not working as well.

 

[mkt]

I’d never be able to hear it but knowing it was there would annoy me. So I’d return it and sleep better.

 

[Lilith]

Yea... I would return the tweeter

Funnily the good speaker plot seems to suggest this also occurs there except at a reduced intensity. Something is supposed to damp the resonance but it's not working as well.

Just wonder because that resonance is seen in many measreuments:

 

[HarmonicTHD]

That's the measurement with periodic pink noise and moving the mic at the listening position for both speakers. SPL was around ~78 dB(C) at listening position.

Repeated it once more:

Instead of you and everyone keep guessing whether it is according to spec or not.

Did you ask Neumann about it? They usually respond within 24hrs (working days). By now we would have had an answer.

What do you think?

(BTW One of their developers is even a member here too and always quite forthcoming)
(Edit. Typo)

 

[Lilith]

Instead of you and everyone keep guessing whether it is according to spec or not?

Did you ask Neumann about it. They usually respond within 24hrs (working days). By now we would have had an answer.

What do you think?

(BTW One of their developers is even a member here too and always quite forthcoming)

I asked and sent them the data. Waiting for reply.

I also called last week and they told me I can't measure this and that every speaker is tested in the company. I understand that I can't measure this correctly absolute wise, but if I measure both speakers "wrong" and they show a difference (always...independent of position, mic position, etc.) I wonder if something is wrong with it. They also offered to measure it, but I can return them for ~14 weeks still and I want to risk damage when sending them in.

 

[HarmonicTHD]

I asked and sent them the data. Waiting for reply.

I think there is a public holiday in (some of ?) Germany today.

 

[ernestcarl]

At the end of the day, if you still cannot go on without thinking about that particular cosmetic wort, might as well return/exchange the afflicted monitor — if they accept the reason.

My own monitors deviate from each other the most past 10 kHz esp. since one of the acoustic lenses is placed rather offset. After 10? years I still can’t tell one is performing better/worse over the other.

 

[Lilith]

I think there is a public holiday in (some of ?) Germany today.

I wrote Monday ... This is only in some states and not where the company is. But I have holidays...

 

[Lilith]

At the end of the day, if you still cannot go on without thinking about that particular cosmetic wort, might as well return/exchange the afflicted monitor — if they accept the reason.

My own monitors deviate from each other the most past 10 kHz esp. since one of the acoustic lenses is placed rather offset. After 10? years I still can’t tell one is performing better/worse over the other.

You' re talking about the KH120? How did you figure that out?

 

[HarmonicTHD]

I asked and sent them the data. Waiting for reply.

I also called last week and they told me I can't measure this and that every speaker is tested in the company. I understand that I can't measure this correctly absolute wise, but if I measure both speakers "wrong" and they show a difference (always...independent of position, mic position, etc.) I wonder if something is wrong with it. They also offered to measure it, but I can return them for ~14 weeks still and I want to risk damage when sending them in.

Ah. One more thing. I just remembered.

May I asked, where did you position the microphone in reference to the tweeter?

Sorry if you posted it before and I overlooked it.

Edit: never mind. Was a stupid idea. I just remembered that the acoustic axis of the Neumanns is not the tweeter axis. But if this would be causing the effect you would see it in both speakers. Therefore please discard.

 

[Lilith]

Ah. One more thing. I just remembered.

May I asked, where did you position the microphone in reference to the tweeter?

Sorry if you posted it before and I overlooked it.

When I measure both speakers at the same position the mic was directing to the tweeter in a distance of ~10 cm. I move the mic slightly (~2 cm) from measurement to measurement to rule out diffraction issues. That was relatively uncritical.