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Neumann KH 80 DSP Monitor Review

Absolute

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It's not about the KH 80 or splitting hair, it's about using a top notch measuring gear to its full extend.
It's like using a super-computer for sum up someone's shopping.
How so? The Klippel does the exact same thing regardless of how you want it to show the calculated graphs. The system works perfectly, this debate is about getting the reference point as perfectly suited as possible to sum the measurements up in the prettiest possible graph. It literally makes no difference whatsoever to the actual measurements, and those are included for all to see.

If it's important to show the prettiest possible graph in order to make everyone happy, then by all means. I don't care what owners, manufacturers or graphoholics think. I want to know the actual performance of a speaker, and the Klippel system already shows us that. Allowing for some small deviations due to mic calibration errors.
 

Krunok

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yes and most of this thread is off-topic if you have ever participate in an internet forum. Off-topic, the magical worlds of the forums. You are discussing the methodology not the review. Open a thread and name it "discussion on @amirm measurement methodology" so I can skip it.
If you have any reasonable experience in participance in internet forums you would know that Moderators are to judge that. You made your proposal and Mod has seen it so bragging more about it is totally meaningless. And also off-topic.
 

Juhazi

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Lots of discussions about the Klippel system, but I can't find any reference on the measurement mic Armim is using.
It's a good one with cal file. It was in another thread.

I'm still wondering if the 60cm measurement distance (plus other layer) is making most of the troubles discussed lately. With such small distance reference axis error comes too dramatic.

Distortion is most reliable done in nearfield, but the mic gets easily distorted. (These miniatyre desktop speakers can't play that loud)

Again - there are many other important measurements too, that will reveal problems and design flaws! Eg. response&distortion at several spl will show compression.

5ms gating, no smoothing shows how mic distance getting longer adds wiggles in response.

er18dxt 5ms nosmo variable distance to mic and wall.jpg
 
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BYRTT

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I'm mathematically and computer retarded, can anyone use the supplied graphs from the Neumann to change the calculation of the listening window to use the - 10 degree vertical angle as the reference? If @napilopez is right to be concerned, we should see a significant difference in the listening window average.
@BYRTT? You seem to be a magician with that virtual EQ program and graphs :)
Listening window in VituixCAD for the EQ models was set to +/-30º hor and +/-10º for verticals and step up 10º a time make little difference up to about 50º where VHF area gets depressed a bit as was it some low Q broad HF shelve filter, and deffently it makes no difference to any warfs NFS plotted in analyze. Looks many don't like the result but think theres a chance scan was perfect and even it could be the low end is really not compressed but how the port tuning is strecthed to reach as low a reach as possible.

But don't be sad on a panthers graphs race Neumann KH 80 looks run over all the others so far ...;)... Congratulations for that ...:cool:... btw all six graphs are divided with microphone calibration but it doesn't mean anything below 12kHz :).

So_far.png
 

Krunok

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I'm still wondering if the 60cm measurement distance (plus other layer) is making most of the troubles discussed lately. With such small distance reference axis error comes too dramatic.
Is measurement distance specified in CEA2034?
 
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Neumann obliterated the competition so far. KH 80 has a lovely pure midrange. Whereas Samsung 305P MKII has no energy in the midrange and peaks in lower treble. The rest of the measured speakers are meh.
 

ctrl

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Thanks BYRTT!

So, this really bothers no one? Every measurement shows comb filtering in the same frequency area - what are the chances?
panther_1.jpg
 

aarons915

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If you end up reviewing something like a Genelec 8030 for example, and you use the same procedure as you used here (high output level, measured at tweeter height), I'm willing to bet you'll spark the exact same debate all over again, because, just like the KH 80, it's a small speaker that is prone to bass compression and its acoustical axis is not the tweeter. And once again, people will point out that your measurements don't agree with anyone else's, and they'll be right to do so.
I think people are making a mountain out of a molehill here, changing the drive level to be the recommended 2.83V for passive and 79db @ 2m for active is a simple adjustment that I think should be made but it shouldn't change the measurements that much.

My bigger disagreement is about the manufacturer's "suggested" axis, or in other words the axis that will create the prettiest graph. Revel suggests 7" above the tweeter axis for the M126be, my question is why? Most people place bookshelf speakers with the tweeter axis close to ear level so why wouldn't we measure that way? I say Amir picks either the tweeter axis or half-way between the tweeter and midrange and sticks with that for consistency. I think most of us want honest, accurate results more than pretty graphs.
 

Krunok

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I think people are making a mountain out of a molehill here, changing the drive level to be the recommended 2.83V for passive and 79db @ 2m for active is a simple adjustment that I think should be made but it shouldn't change the measurements that much.
When it comes to measurements you shouldn't be doing such assumptions. You should make sure your measurement protocol is bullet proof.

My bigger disagreement is about the manufacturer's "suggested" axis, or in other words the axis that will create the prettiest graph. Revel suggests 7" above the tweeter axis for the M126be, my question is why?
My guess would be that spec is coming from Revel engineers who designed M126Be so they probably know why.
 
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I think people are making a mountain out of a molehill here, changing the drive level to be the recommended 2.83V for passive and 79db @ 2m for active is a simple adjustment that I think should be made but it shouldn't change the measurements that much.

My bigger disagreement is about the manufacturer's "suggested" axis, or in other words the axis that will create the prettiest graph. Revel suggests 7" above the tweeter axis for the M126be, my question is why? Most people place bookshelf speakers with the tweeter axis close to ear level so why wouldn't we measure that way? I say Amir picks either the tweeter axis or half-way between the tweeter and midrange and sticks with that for consistency. I think most of us want honest, accurate results more than pretty graphs.
It’s due to a passive crossover. The lobe is pointing up, hence ear should be above the tweeter. Speakers like that also sound better while customers are standing up at the store. It’s an antiquated design. No such problems with DSP powered speakers.
 

Pio2001

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So, this really bothers no one? Every measurement shows comb filtering in the same frequency area - what are the chances?

Something is near the tweeter, 3-3.5cm. If the mic gets that close it could be a reflection.
A simple hypothesis : could it be that most of these speakers have dome tweeters that are about the same diameter and depth ? This would just be the response of any pulsating dome of this size.
 

aarons915

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It’s due to a passive crossover. The lobe is pointing up, hence ear should be above the tweeter. Speakers like that also sound better while customers are standing up at the store. It’s an antiquated design. No such problems with DSP powered speakers.
I know it's due to it most likely sounding and measuring better but most people aren't going to place them 7" under ear level was my point. The official Performa3 stands won't place them 7" under ear level either. They should be measured how the majority will use them, not based on what produces the best measurement in my opinion.
 

ctrl

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Those oscillations are not because of comb filtering. I suggest you read how NFS works.
I mean something causes an "comb filter like effect" by interference - e.g. by reflection.

My bigger disagreement is about the manufacturer's "suggested" axis, or in other words the axis that will create the prettiest graph. Revel suggests 7" above the tweeter axis for the M126be, my question is why? Most people place bookshelf speakers with the tweeter axis close to ear level so why wouldn't we measure that way? I say Amir picks either the tweeter axis or half-way between the tweeter and midrange and sticks with that for consistency. I think most of us want honest, accurate results more than pretty graphs.
If you want "honest, accurate results" then you should measure a loudspeaker as intended by the manufacturer/creator, else you will get an unintended vertical radiation pattern.

All non coax-systems exhibit radiation lobes in the vertical plane around the crossover frequency. If the crossover is 4th order Linkwitz-Riley the radiation lobe is straight on-axis. If the tuning is optimized between tweeter and woofer, then the radiation lobe "stands on right angle" at this position.
If a third order butterworth crossover is used, the radiation lobe is tilted. Tweeter and woofer with same polarity +15°, otherwise -15°. This way you could compensate a tilted baffle or optimize for tweeter axis.
 
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