Neumann KH 80 DSP Speaker Measurements: Take Two

[DJBonoBobo]

NEUMANN KH750 DSP : Crossover frequency: 80 Hz fixed or 60 - 100 Hz via Neumann.Control app
Maybe legal requirement for those who don’t use the app.

The old info on the webpage was misleading. They didn´t implement this functionality to the app yet, so the description was false. Some time ago i got the info from Neumann support that they want to implement this feature in "one of the next updates" of the app. So it is still not possible to change the crossover frequency, even with the app.
It is possible though that the sub automatically uses a higher setting for the KH80. I have the KH310 and the XO is 80Hz. Maybe it´s higher if the KH80 is specified in the app. (You can tell the KH750 if you use KH80, 120, 310 or 420).

 

[jhaider]

KH120 has a much higher SPL bass output in comparison (+13 dB).

Where are you getting that information? Did you miss a decimal place?

Sound und Recording measured scant differences between KH120 and KH80 in bass capability ("Basstauglichkeit") at 10% THD averaged over 50-100Hz: 97dB for KH80 (see Sound und Recording Studiomonitor Special, at 32) and 98dB for KH120 (see id., at 278).

If you want significantly more bass capability in that size class, JBL LSR705i/P is the only speaker I know of that will get you there. S&R measured 101dB under the same conditions (Sound und Recording 8/19, at 55).

What an irritating limitation for a sub that costs that much.

Why? If you're not using their integration tool and care about sound quality you'll be using external bass management. The subwoofer has a switch to disable bass management, and claimed response out to 750Hz when bass management is disabled. That extension makes integration easier than many subs.

 

[DJBonoBobo]

The old info on the webpage was misleading. They didn´t implement this functionality to the app yet, so the description was false. Some time ago i got the info from Neumann support that they want to implement this feature in "one of the next updates" of the app. So it is still not possible to change the crossover frequency, even with the app.
It is possible though that the sub automatically uses a higher setting for the KH80. I have the KH310 and the XO is 80Hz. Maybe it´s higher if the KH80 is specified in the app. (You can tell the KH750 if you use KH80, 120, 310 or 420).

Addendum: I tried to set up a KH120 and a KH420-system in the Neumann-app. Subwoofer measurements show the same FR afterwards. I don´t know for KH80 because i could not try them, but if it´s the same for 120 and 420 i guess the XO is fixed to 80 Hz.

 

[ernestcarl]

... claimed response out to 750Hz when bass management is disabled. That extension makes integration easier than many subs.

750Hz? That's certainly unique... still, I'd say for myself, requiring an iPad to use the sub's internal bass management is an irritating limitation. And if what DjBonoBobo says above is true, then... just nevermind... I'd chooose external bass management with a cheaper Rythmik sub.

 

[GuyLayfield]

Thank you very much for investigating the measurements and joining the forum to share them. Much appreciated.

I wish you had contacted me though and shared the same sample for testing. With me testing a different speakers than yours, and measurement parameters varying from Klippel (I use higher resolution for example), we still have some unknowns that could have been worked out.

For now, the big difference I see is that your measurements are at acoustic center and mine are relative to tweeter axis. I suspect there is diffraction when measured at tweeter axis that shows up in my and Klippel's measurements that don't show up in yours.

Anyway, if you are willing, I would be very interested in measuring the same speaker sample.

Hi everyone, apologies for the late reply to all the messages this week, and for the time it took us to respond in the first place. We are a small and very busy team dealing with the same disruption as everybody else right now.

Sorry also for not contacting you first. Our aim was not to disprove the measurements on this forum but to show that our measurement method is reliable (particularly for the bass where the anechoic chamber limitations can be an issue). There were a lot of comments here suggesting possible errors in our measurement procedure. We thought it was important therefore to verify with an independent third party, and we are satisfied that we have validated our measurement method.

Of course this doesn’t explain the differences to the measurements shown previously here. We would be happy to send the unit from Klippel, but as you’ve now ordered a sample, measurements of your unit could also be very informative.

 

[infinitesymphony]

Where are you getting that information? Did you miss a decimal place?

Sound und Recording measured scant differences between KH120 and KH80 in bass capability ("Basstauglichkeit") at 10% THD averaged over 50-100Hz: 97dB for KH80 (see Sound und Recording Studiomonitor Special, at 32) and 98dB for KH120 (see id., at 278).

Just going by the data on Neumann's website:

KH 80

KH 120

 

[KaiserSoze]

View attachment 49111

This is exactly how I pictured Amir would look without the hat.

 

[jhaider]

Just going by the data on Neumann's website:

KH 80
View attachment 68757

KH 120
View attachment 68758

Thanks for showing your source. That's a pretty bad typo. Neumann couldn't intend to claim KH120 has 0.3dB greater bass headroom than KH310. That is not consistent with third-party measurements of both speakers.

@GuyLayfield, FYI.

 

[witwald]

With respect to acoustic center, I think this is one of those instances where near-field measurement may cause some issues. Specifically, the Klippel system measures the speaker at 1 foot/0.3 meter or so. This heavily accentuates angular differentials. In anechoic chambers attempt is made to measure in the far field by using 2 meter measurement distance or so. This lowers the accuracy of the acoustic center since small differences in location of the microphone there, doesn't make as much angular difference.

Is it possible to use the Klippel system to take measurements at a distance of 1.0 metres? That would be more representative of a nominal near-field monitoring situation, wouldn't it? Why take measurements that are potentially nonrepresentative of the user's application--doesn't that just cause confusion by producing data that doesn't apply particularly well to the task in question? Even a measurement distance of 0.6 metres would be much better than the present 0.3 metre distance, wouldn't it?

 

[witwald]

This is not quite true. Anechoic chambers also have to be "calibrated" at <100Hz, unless it is very large (and maybe even then for really low frequencies). So I would trust the math here (used by Klippel) over the "calibrated measurement" in an anechoic chamber.

I would assume that the "calibration" (or "correction") of an anechoic chamber's effect on the measured low-frequency response of loudspeakers would be something that is quite well thought out and mathematically sound. The correction is probably much simpler to apply than the complex mathematics and attendant underpinning modelling assumptions that are involved in the Klippel Near Field Scanner System. It would seem that using a good, calibrated anechoic chamber of a reasonable size is still preferable, as it really gets to the nuts-and-bolts of what is being measured. Of course, not everyone has access to an anechoic chamber such as this.

 

[napilopez]

Is it possible to use the Klippel system to take measurements at a distance of 1.0 metres? That would be more representative of a nominal near-field monitoring situation, wouldn't it? Why take measurements that are potentially nonrepresentative of the user's application--doesn't that just cause confusion by producing data that doesn't apply particularly well to the task in question? Even a measurement distance of 0.6 metres would be much better than the present 0.3 metre distance, wouldn't it?

You seem to be misunderstanding how the system works. The NFS takes measurements in the nearfield, but the math lets it extrapolate those results to farfield. That is the same the same thing the klippel results Neumann posted is doing. Those results have shown the NFS is certainly capable of doing an accurate bass assessment to match tried and trusted techniques like anechoic chambers and ground plane measurements.

I would assume that the "calibration" (or "correction") of an anechoic chamber's effect on the measured low-frequency response of loudspeakers would be something that is quite well thought out and mathematically sound. The correction is probably much simpler to apply than the complex mathematics and attendant underpinning modelling assumptions that are involved in the Klippel Near Field Scanner System. It would seem that using a good, calibrated anechoic chamber of a reasonable size is still preferable, as it really gets to the nuts-and-bolts of what is being measured. Of course, not everyone has access to an anechoic chamber such as this.

To be fair to leftcoasttim that's an old post from a thread that's been going on for months =]. The anechoic chamber calibration can vary depending on the speaker's radiation patterns in the bass. Harman speakers sometimes show deviations in the bass when measured in different chambers, so it's not foolproof. That's why some manufacturers like Neumann and Dutch &Dutch use ground plane measurements.

 

[infinitesymphony]

Thanks for showing your source. That's a pretty bad typo. Neumann couldn't intend to claim KH120 has 0.3dB greater bass headroom than KH310. That is not consistent with third-party measurements of both speakers.

The KH 310 A and KH 310 D pages list the same measurement. My recollection about the Klein + Hummel O300Ds these are based on is that there were complaints regarding low SPL with bass-heavy material when not using them with a subwoofer. Cross them over <=100 Hz and they are significantly louder than the KH 120s (116.3 dB vs. 111.1 dB).

 

[amirm]

Is it possible to use the Klippel system to take measurements at a distance of 1.0 metres?

Probably. It would partially defeat the purpose of performing near-field measurements though. In my case it is not practical as I don't have a cylinder of space that is 2 meters wide and some 11 to 12 feet high. I have 12+ foot high ceiling but have obstructions width wise as the arm rotates.

That would be more representative of a nominal near-field monitoring situation, wouldn't it? Why take measurements that are potentially nonrepresentative of the user's application--doesn't that just cause confusion by producing data that doesn't apply particularly well to the task in question?

The two have nothing to do with each other. Klippel NFS systems claim to fame is to measure in near field, then compute far field. This sharply increase signal to noise ratio of the measurement system allowing it to do its work in ordinary spaces. Once there, the system can predict the sound field at any distance equal to, or longer than the measurement distance. The standard calls for measuring at 2 meter which is what Klippel uses, and then present at 1 meter. So the data is as you ask.

As to matching the operating distance, that is the beauty of the Klippel in that I can tell it to plot the response at any distance -- something you can't do with anechoic measurements made at one point.

 

[jhaider]

The KH 310 A and KH 310 D pages list the same measurement.

I'm confused. Would you expect KH310A and KH310D to have different capabilities in a region governed by the linear displacement of the (common, I assume) woofer?

My recollection about the Klein + Hummel O300Ds these are based on is that there were complaints regarding low SPL with bass-heavy material when not using them with a subwoofer. Cross them over <=100 Hz and they are significantly louder than the KH 120s (116.3 dB vs. 111.1 dB).

I'm not sure what you're getting at here. There is simply no way KH120 provides the claimed bass headroom. The woofer, cabinet, and amp are all too small. Their website has a typo. Third party testing (same source) proves that to be the case, and also shows minimal bass headroom difference between KH80 and KH120 with KH310 providing significantly higher bass headroom. Third party testing also shows that a even much longer throw 5.5" woofer and 6x the power (i.e. JBL LSR705) does not come close to the claimed KH120 numbers.

 

[infinitesymphony]

I'm confused. Would you expect KH310A and KH310D to have different capabilities in a region governed by the linear displacement of the (common, I assume) woofer?

Not necessarily, although with DSP it's not outside the realm of possibility. Genelec sometimes release incremental improvements of the same speaker between A and D versions, granted there's usually a delay between model release dates.

But that was not my intended point, I just wanted to make the observation that these same specs have been added to more than one page on Neumann's website, and they are also present in the manuals for KH120 and KH310. Most people seem to praise Neumann for their attention to detail regarding measurements and specs, so a typo like this, replicated everywhere, would seem to be out of character.

 

[q3cpma]

I'm confused. Would you expect KH310A and KH310D to have different capabilities in a region governed by the linear displacement of the (common, I assume) woofer?



I'm not sure what you're getting at here. There is simply no way KH120 provides the claimed bass headroom. The woofer, cabinet, and amp are all too small. Their website has a typo. Third party testing (same source) proves that to be the case, and also shows minimal bass headroom difference between KH80 and KH120 with KH310 providing significantly higher bass headroom. Third party testing also shows that a even much longer throw 5.5" woofer and 6x the power (i.e. JBL LSR705) does not come close to the claimed KH120 numbers.

These models being near in maximum SPL is quite coherent with the measurements. Ported vs sealed is the obvious reason for this.
The spec themselves don't seem to match the graphs, though.

 

[LTig]

[..] My recollection about the Klein + Hummel O300Ds these are based on is that there were complaints regarding low SPL with bass-heavy material when not using them with a subwoofer. Cross them over <=100 Hz and they are significantly louder than the KH 120s (116.3 dB vs. 111.1 dB).

This is correct. I've read somewhere in an article or interview that the woofer of the KH310 has about 7 dB higher SPL capability compared to the O300D. That is a lot!

I added a sub 2 years after I got my O300D and it made quite an improvement in both bass SPL and midrange clarity. Consequently I later decided not to upgrade to the KH310 because it's major improvement (bass capability) would be wasted as I use a sub. I'll get them when the O300D finally break beyond repair.

 

[Pio2001]

I would assume that the "calibration" (or "correction") of an anechoic chamber's effect on the measured low-frequency response of loudspeakers would be something that is quite well thought out and mathematically sound.

Calibration of an anechoic chamber is not done with maths.
They just put a subwoofer that is supposed to have a flat frequency response in the room. The measurement result is the calibration curve of the room.

 

[thewas]

These models being near in maximum SPL is quite coherent with the measurements. Ported vs sealed is the obvious reason for this.

True, though max SPL doesn't tell the full story which is relevant for our hearing like IMD does, here are IMD measurements of both:

The intermodulation distortions in the mid range are reduced by 10 - 15 dB and that can be really audible.

 

[q3cpma]

True, though max SPL doesn't tell the full story which is relevant for our hearing like IMD does, here are IMD measurements of both:

View attachment 68926 View attachment 68927

The intermodulation distortions in the mid range are reduced by 10 - 15 dB and that can be really audible.

Indeed, as expected from a 3-way (even if a ported 2-way speaker is kind of a 3-way). But now, I really wonder how incredible the KH310 would be if it was properly ported.