Neumann KH80 DSP Monitor Measurements #3

[AudioStudies]

YES!

Yes to what?

 

[JohnYang1997]

Yes to what?

Good post, I guess.

 

[ROOSKIE]

It's already measured at 105db. What more power handling do you need?

I believe that 105db is at .3 meters.
These speakers are not capable of low distortion output at 105db in the Bass or lower mids at a normal (1-2 meter) listening range.

Here are Newman's distortion specs for this model, at high SPL

 

[JohnYang1997]

I believe that 105db is at .3 meters.
These speakers are not capable of low distortion output at 105db at a normal (1-2 meter) listening range.

Shouldn't measurements be done at 1 meter from the speakers? Yet I do understand that it's still less that general listening distance of 2m or so.

 

[AudioStudies]

Good post, I guess.

thanks, I appreciate a compliment from a smart guy like you

 

[amirm]

Shouldn't measurements be done at 1 meter from the speakers? Yet I do understand that it's still less that general listening distance of 2m or so.

Not with the system I have. It is called "near-field" scanner for a reason. By using short distance the signal to noise ratio becomes far better. It requires a lot of math (and money) to compute the far field though.

 

[ROOSKIE]

Shouldn't measurements be done at 1 meter from the speakers? Yet I do understand that it's still less that general listening distance of 2m or so.

There is no should, but 1meter is common. I believe here many of the tests are at .3 meter and then sometimes mathematically corrected for 1m. The Kipple gets close.

oops looks like I was beaten to the punch...

 

[phoenixdogfan]

It's already measured at 105db. What more power handling do you need?

That's at .3 meter away! At one meter that drops to 90db.

Look I've never heard these, but I very much doubt they could be played very loud at all in a normal listening room without sounding strained. Even with a sub, I don't see these as much more than a small/medium signal device for nearfield listening, and that is not how most people prefer to listen.

 

[napilopez]

Where and when will it all end? Will we develop computer models for the thermal conductivity of all the speaker components to determine how they relate back to speaker measurements? After all some people prefer a warm house and others a cooler environment. Or since the room will change the performance anyway, are we just spinning in circles? Are there any mandates for what temperature should be used in the chambers? With powered monitors, won't the temperature be dependent on what type of music is being played and the volume? I very much appreciate ASR and others with knowledge and equipment to investigate these issues. More than that I appreciate the dedication of those who work so hard. But is there a point of no return? Are we falling into a rabbit hole that may have no carrots at the bottom? Can science sometimes go too far into a gnat's ass?

Well, I think the key point of this experiment was that it should to those of us who don't have as much experience designed speakers as the folks at neumann that temperature can make a difference. S 2-3dB shelf -- below 100hz is definitely audible, even if that area is very room dependent. Luckily a refrigerator or Amir's garage in the winter is certainly not representative of I think most people's rooms, I'd imagine, so no need to worry about that. But the most important thing is we now know the cause.

The spinorama standard does specify a temperature range, by the way, which I don't think anyone expects amir to adhere to adhere to strictly unless we want to fund an HVAC system + bills =]

"Testing shall be conducted at an ambient temperature of 22 °C ± 5 °C (71.6 °F ± 9 °F) and relative humidity of 30 % to 80 %. If the conditions are different, they shall be noted at the time of the test. Both of these items shall be recorded at the time of the tests. The ambient atmospheric pressure (in Pascals) shall also be recorded."

Again, the important thing is now we know! Of all the things people suggested was the cause, temperature was definitely very low on the list.

When I see how high these things rate, I really have my reservations. They're just too small for use in anything other than a small desktop/studio monitor, yet their preference rating is above all the Revels, Kefs, and on a par with the Genelecs, and I just don't see it.

Probably highlights that the preference ratings don't take into consideration the power handling/dynamic range of speakers, which certainly makes them incomplete as a predictive model.

And that's just because frequency response changes when a speaker can't handle the desired power =]. As always, the preference score is only valid when used within the exp comfort range of the 'weaker' speaker. It's up to you to figure that out, but it's normally pretty obvious.
The couple of times I've listened to these in my living room crossed with a sub, btw, they sounded fantastic at my normal listening levels.

 

[Pepperjack]

So from what I am hearing this is not great for a home theater set up?

 

[richard12511]

In the original test, he preferred the JBL.

The first model was only a 74% chance

 

[amirm]

So from what I am hearing this is not great for a home theater set up?

Definitely not.

 

[AudioStudies]

Again, the important thing is now we know! Of all the things people suggested was the cause, temperature was definitely very low on the list.

I am also glad we know. But should it be taken any further than it has? I have my doubts that it should.

 

[phoenixdogfan]

Well, I think the key point of this experiment was that it should to those of us who don't have as much experience designed speakers as the folks at neumann that temperature can make a difference. S 2-3dB shelf -- below 100hz is definitely audible, even if that area is very room dependent. Luckily a refrigerator or Amir's garage in the winter is certainly not representative of I think most people's rooms, I'd imagine, so no need to worry about that. But the most important thing is we now know the cause.

The spinorama standard does specify a temperature range, by the way, which I don't think anyone expects amir to adhere to adhere to strictly unless we want to fund an HVAC system + bills =]

"Testing shall be conducted at an ambient temperature of 22 °C ± 5 °C (71.6 °F ± 9 °F) and relative humidity of 30 % to 80 %. If the conditions are different, they shall be noted at the time of the test. Both of these items shall be recorded at the time of the tests. The ambient atmospheric pressure (in Pascals) shall also be recorded."

Again, the important thing is now we know! Of all the things people suggested was the cause, temperature was definitely very low on the list.



And that's just because frequency response changes when a speaker can't handle the desired power =]. As always, the preference score is only valid when used within the exp comfort range of the 'weaker' speaker. It's up to you to figure that out, but it's normally pretty obvious.
The couple of times I've listened to these in my living room crossed with a sub, btw, they sounded fantastic at my normal listening levels.

"the preference score is only valid when used within the exp comfort range of the 'weaker' speaker. It's up to you to figure that out, but it's normally pretty obvious." Not alway. I think when we get to things like the Genelec 8351 vs the Kef R3 vs a Revel F228be something like the respective large signal capability of each will not be obvious, and a spinorama certainly won't tell us much about that either.

 

[Lao Lu]

Shouldn't measurements be done at 1 meter from the speakers? Yet I do understand that it's still less that general listening distance of 2m or so.

Still bleeding heavily from the ATC 19 scuffle, I would like to hear from anyone who uses these (or the next two models up size-wise) for home listening; HOW do they sound to your ears (which I am more than willing to recognize, in a sincerely proffered act of obeisance, fall far short of Klippel or any other empirically derived measuring devices)...? In particular for recordings of non-amplified acoustic events first conceived preternaturally in the minds of Beethoven and like. 感謝 ！

 

[tomtoo]

Now the Neumann KH80 DSP is a true reference speaker. You can even measure temperatur with it.

 

[jhaider]

This was one of the earliest speakers I measured with the Klippel Near-field scanner. So naturally (or not), there were a lot of suspicions that it could actually recreate anechoic chamber measurements such as provided by the company:

To be fair, you mean the anechoic measurements provided by the company and the independent measurements provided by Prof. Goertz, as published in 2017 by Sound und Recording.

Meanwhile @GuyLayfield reached out privately to me offering that we work together to see what is going on. Suspicion quickly went after the temperature difference for when I tested mine (in winter) and theirs (temperature controlled at 21 degrees C). Guy showed me a couple of useful slides from Klippel indicating changes in speaker parameters based on temperature:
...
Meanwhile my sample arrived and measured it. And what do you know, the low frequency dip had disappeard:
...
We still had to verify the problem was temperature. So Guy put a unit in the fridge overnight...

Fantastic collaboration, gentlemen! That is a fascinating observation. Maybe others did, but I had no idea cold temperatures affected woofers so much.

Yes, it looks the same! It is a bit flatter in bass but I think it has tiny variations here and there. According to Guy, we are now with +-0.6 dB from their measurements.

We don't know if the variations are because my measurements are wrong, or theirs. There is no gold reference here.

As you write, every measurement taken has experimental error. That really shouldn't need to be said: didn't everyone take lab classes in high school and undergrad?

I think two unsmoothed measurements of different sample units of a given speaker, taken on different continents, being within 1.2dB broadband of each other is extraordinary agreement. Again, both you and @GuyLayfield deserve heaps of praise for persevering and reaching this point. Neumann also deserves credit for designing and producing speakers of such consistency that such results are possible.

When I see how high these things rate, I really have my reservations. They're just too small for use in anything other than a small desktop/studio monitor, yet their preference rating is above all the Revels, Kefs, and on a par with the Genelecs, and I just don't see it.

It is very useful to know that a speaker will make a very good desktop/studio monitor. I suspect most of these speakers in hobbyists' systems are deployed for for desktop listening. Mine are.

 

[Mnyb]

Is it air density ( as a consequence of temperature) ? That makes the difference ? wonder how a bassreflex speaker would work in the alps 2000 meters above sea level

 

[carlosmante]

Where and when will it all end? Will we develop computer models for the thermal conductivity of all the speaker components to determine how they relate back to speaker measurements? After all some people prefer a warm house and others a cooler environment. Or since the room will change the performance anyway, are we just spinning in circles? Are there any mandates for what temperature should be used in the chambers? With powered monitors, won't the temperature be dependent on what type of music is being played and the volume? I very much appreciate ASR and others with knowledge and equipment to investigate these issues. More than that I appreciate the dedication of those who work so hard. But is there a point of no return? Are we falling into a rabbit hole that may have no carrots at the bottom? Can science sometimes go too far into a gnat's ass?

>"thermal conductivity"? Most probable is an effect of Temperature on the Young's Modulus of the suspension materials (surround and spider).

 

[Music1969]

I asked @amirm about his cold garage measurements back in January !

https://www.audiosciencereview.com/...-will-be-measuring-speakers.10725/post-298142

He did answer my question with a technical reply though, so he had already considered it.