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Neumann KH 80 DSP Monitor Review

Ilkless

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Sure, this is a very competent design but i dont think taht problem exclusively apply to thin plywood boxes with straight edges, one example is earl geddes speakers. Generally very good directivity and large roundovers on all edges but the 0° axis (not the listening axis) is a little ragged. According to him that is a concious compromise to get the best sound where you listen. The speakers are toed in 20 or 18° wich will give you a wider sweet "spot" due to time intensity trading and balances out the a little bright 0° axis when you are at that axis from one of the speakers with the weaker off axis from the other. If you would EQ the 0° axis perfectly flat all other would be crappy
I am familiar with the Geddes oblate spheroid. The 0° dip is a consequence of how low diffraction the waveguide is. It is mathematically optimised for low diffraction especially in the throat (prioritising that over SPL/compression driver loading), giving the happy problem of such a coherent wavefront at the mouth that there is a minimal amount of reflection at the mouth that is a single high-Q dip at ONLY 0° horizontal. The listening window is excellent - Stanford's 3D3A measured one example.

Geddes had a post about it on DIYAudio that I would dig up were I not traveling right now.
 

Thomas savage

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From someone who tested (using a Klippel for quite some time) and posted this data for everyone to see on my now-defunct website medleysmusings.com, here are my takes:
1) When you're starting off, it's easy to be enraptured with the new toy. It's easy to take things personally. Years away and experience showed me that in my early days, those who I viewed as being combative were (mostly) trying to help and/or curious of certain "inaccuracies" themselves.
2) No matter what is said to/from this is what I am seeing: a bit of an ego because you have the Klippel... and the Klippel doesn't lie. I was that same person for quite some time. I fully admit it. It took me a few months to get over myself. I believe this whole ordeal is no different... I think cooler heads will prevail and time will lead to the same result that I ultimately came up with in #1 above.
3) The purpose of the NFS is to offer the user automation. That's where the cost really lies. Heck, just a standard loudpseaker turntable and CLIO costs upwards of $5k. Numerous software (as well as Klippel) also offer the ability to conduct intelligent nearfield/farfield splicing based on the DUTs effective diameter. But the big benefit of the NFS to me is the wholly automated way of performing the measurement and obtaining the results that would otherwise take hours of manually adjusting. I know. I did this for years myself. I would legitimately spend a good 8 hours to test a single drive unit: from build up, set up, record, analyze, report findings and tear down. The ability to automate the testing to a high degree of accuracy and repeatability is ... well, a god send, to be blunt.
4) With 3 above, and with the desire of this site to be so focused on objective data, I don't understand why re-testing the DUT at the manufacturer specified listening axis isn't performed. First, that's how the 2034 spec says to do it. Second, it's honestly just a no-brainer. Thirdly, if the test is called in to question legitimately then the thread should be updated with the new test results. Or at the very least a huge disclaimer with the points made here should be posted. Still, I've learned that people see graphs and run. They don't take time to read discussion the majority of the time. And unfortunately, as we will see in the future if this thing continues to happen, the internet will be filled with incorrect assumptions about data captured in a non-idealized way. Pages and pages of arguments could have been saved. But, if I'm being honest, I think this has more to do with #2 above.
5) Blitz testing should be avoided at first. I get it. It's a new toy. You want to test a bunch of stuff. But that leads to errors as we are seeing discussed here. At least in the early stages it should be: Perform a test. Post the data. Wait for some feedback. Learn from both it and the viewership's feedback. Implement necessary changes (some of which I believe have been implemented, like the SPL adjustment). And then go forward. Throwing a bunch of data out without taking time to consider what it means leads us to where we are now. I've already seen others on another forum now question the accuracy of this site's testing thanks to this very thread. Think about that for a second. One mis-step and one acknowledgement of said mis-step will now lead to less trust. That's a shame. Truly.

Argue with me if you want. I can point to pages and pages of me going through the EXACT same thing when I first started testing with the Klippel (LSI/LPM, TRF/DIS to be more concise). I've been in the exact same shoes as Amir. And I am the only other person I know of who has used the Klippel to provide data for all. So, I can speak from literal experience on this matter. I made the same mistakes... from letting my ego get in the way by thinking that if I were the owner of said machine then how could anyone question my expertise to not taking time to step back and review what I'm doing. I realize the NFS was a costly undertaking. I know this full well. I hope he can take the time to step back and see that my reply here comes from a place of hope. Hope that he will remember to breathe and evaluate not only his community's concern but also evaluate what his goal is: to provide a lot of data... or provide the most accurate data he can. And I hope you all who seem to be going at this in a spiteful way will try to step back yourselves and ask how you can help the community (not just yourself or not just Amir) learn from this event.

- Erin
Good post , valued experience thanks for that and thanks for the humanity you've shown.
 

Thomas savage

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This plus 1000.

There is a good deal of simple wisdom in this post. And obviously it was gained from personal experience.

The biggest issue of all in Amir not doing a retest is an immediate erosion of trust by a large number of people. I'm not saying I distrust him, but there are plenty who will. Once that has happened, most especially at the very beginning of the testing history, it will take a couple dozen more speakers measured without any glitches to get most of that trust back. And some of that trust will never be fully regained.

IMO, benefits of doing a re-test far, far outweighs any negatives or time involved in the second round of testing.

I shake my head in the resistance to this one retest. Especially as a retest was immediately planned on another speaker due to results being a bit off from expectaions (speaking of the Kali). Why the hard line against a retest of the KH80? Humor the few dozen or few hundred of us this one time.
Trust is everything, it's not necessarily exclusively about right and wrong. Sometimes you have to be conscious of other people's perception of what's happened and going on and cater to that.

We went through similar things when we started testing electronics, I actually thought the speaker testing had got off to a much better start but alas it's proving challenging.

We have a great platform here it's to the benefit of everyone for us to get this right. Rather than throwing stones , hissy fits and the like we have to bind together and all do our part .
 

aarons915

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At this point I wouldn't mind seeing the KH 80 retested either but if it isn't it's not that big of a deal. I think people just pissed off Amir from all the demands so he wasn't going reward bad behavior. He has taken the suggestions and made improvements to the newer tests so I don't see it as a big deal. If people aren't satisfied with that and we aren't going to get a retest maybe just delete the review altogether and move on.
 

jhaider

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Regarding the use of KH80 with subwoofer(s) - how do you cross them?

Response of KH80 drops like stone below 60Hz. But, to make mains and sub(s) to integrate, they shoud have smooth response slopes on both sides of xo. If subs are crossed above 100hz they shoud be doubled and positioned close to the mains.
I agree. My usual rule of thumb is that the minimum subwoofer crossover frequency is 2x the mains' box tuning.

Here, I use a crossover of either 100 or 120 Hz, and Dirac Live below about 300Hz. DAC/crossover/processor is miniDSP DDRC-24D. There are two subs (Dayton RSS265HF-4 in Velodyne SC-10 cabinet, each powered by an Icepower 500ASP), but they run in mono. Speakers are on mounts that lift them to the correct vertical axis for my seated head ;) and subwoofers are under them on the floor.

I don't remember the exact crossover and correction off hand. The files aren't easily accessible right now because Dirac failed to keep up as they should have - their software broke after the Catalina update, which they should have anticipated and prepared for just like everyone else who writes software.
 

Krunok

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Amateur question here ( i’m doing the learning and fun:)

Would not flat on axis be more important in the extreme nearfield you are supposed to use these speakers ?
It seem almost headphone like ? Would the room contribute much in these circumstances for a listener ?
Acoustically it does but are not are brains able to separate out some reflections and would not this work even better in close nearfield ?
I don't know the answer but I would expect the same as you.
 

hardisj

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Fortunately a lot from that site can still be accessed on archive.org:
Medley's Musings on Archive.org
Indeed. That’s how I’m bringing the data back to my new site. :) (Learned lesson: never assume that a back-up drive can’t fail)

I’ll be hosting the old data as well as new data there. Keep an eye out for ErinsAudioCorner.com (not live yet) and if you want you can also keep up with updates via the Facebook group page: https://www.facebook.com/groups/607627396679113/?ref=share

I’m hoping to have the site live and start producing test data again within the next month or two.
 

hardisj

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Does that mean your Klippel is fuly functional? I also hope your daughter got better in the meantime..
So, when I stopped testing I let the Klippel go. But I am working on getting another one. Hopefully with some extras. I don't foresee me getting the NFS (too much $$). I'm just waiting to get the final quote and then I'll figure out what I can afford. I may have to resort to a gofundme but I'm not sure how I feel about asking for donations.

And, yes, my daughter is doing well. She has a few auto immune deficiencies she will always have to contend with but it's nothing bleak. At one point last year we were literally scared for her life. A lot of sleepless nights. But all is well. I'm actually having her get involved with my site/reviews. She's been playing piano for the last 5 years so I told her for each theme she writes and records I'll pay her $5. I figure this will be a good way for her to learn about physics, testing (logic), coding and have some fun together.
 

BYRTT

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Up to date list after acoustic scan number eight for Harbet Monitor 3, all eight graphs are divided with microphone calibration but think it doesn't mean anything below 12kHz, have changed ratio (not actual covering numbers as 20Hz-20kHz and 5dB) of X verse Y scale to same as SS publish their brochures presented on my 24inch flat panels, that ratio combined the non interpolated resolution amirm produce think focus or zoom good into details, maybe then graphs doesn't look as good as wished for then feel free import txt files yourself and widen ratio of X scale to get curves look relative flatter :).
Z_cyrves_1_publsih.png


Below is same but KH 80 is manipulated for if compression in lows was taken place under sweep, and if the dip at XO frequency was caused by microphone position in space was not offset to same listening axis as Neumann suggest.
Z_cyrves_2_publsih_b.png
 

dukanvadet

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I guess this is a pretty good guesstimate of what could be if the assumptions are true but i dont see the reason to manipulate the measurements like that. Just post neumanns own graph if that is what you believe in. Or draw a straight line. That looks even better.
If you like a measurement of another axis at lower SPL i can understand that even if I dont care as much but there is no substitute for doing that measurement imo.
 

Darkweb

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Amateur question here ( i’m doing the learning and fun:)

Would not flat on axis be more important in the extreme nearfield you are supposed to use these speakers ?
It seem almost headphone like ? Would the room contribute much in these circumstances for a listener ?
Acoustically it does but are not are brains able to separate out some reflections and would not this work even better in close nearfield ?
Absolutely, think about having a conversation in a crowded bar. Your ear/brain can cue into your friend’s voice and somewhat ignore the background noise. Also, your friend’s voice doesn’t sound like James Earl Jones in one room and Pee Wee Herman’s in the next.

Important to remember ear/brain and microphones are very different hearing mechanisms.
 

MattHooper

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Wow...just went through this thread and I'm...uh...unpleasantly surprised at how it has gone.

First, I'm as appreciative as anyone else that Amir is now taking the time to measure speakers. However, things could have gone better here.


That's nonsense. I am trying to get you guys to stop obsessing over small differences in frequency response. I have not even bother to put in the calibration for my microphone in there because 1 dB here and there is not material.
The difference in frequency response shown in your measurements vs the others (which tend to correlate more), should be audible deviations from what the manufacturer specs imply, and from that implied by the measurements taken by others which don't have that bass droop or high end tilt.

Since when did this site stop caring about audible differences, even if minor?

If the manufacturer recommends a certain listening axis to realize the flat response specs they claim, and they have been designed to be used that way by the user, what is the point of measuring "off" that axis? Sure you'll find out how they measure off the recommended axis...but we would want to know how they perform ON the recommended axis. One may as well report how a medication performs when not used as directed.
It's like testing a medication with an attitude like: "This medication says take one pill every 6 hours. But the other brands say take one every 12 hours. For constancy sake, I'll stick to taking all brands only once every 12 hours, including the one that recommends once every 6 hours."
Well, that's not going to be very precise to find out if the medication works as directed!

This seems - I don't know how else to put it - surprisingly sloppy for a site with "science" as part of it's title and remit. It can lead, as it appears to have here, to the results looking like the manufacturer was exaggerating it's claims. That's not a fair stain to leave on a manufacturer if it's due to the experimentor's decision to *not follow the manufacturer's own recommendations.*


What do you think your ears are? That they care about these tiny differences when assessing two different speakers?
I find this very odd. You have sweated over incredibly precise differences in electronics and DACs, even bothering to go over measured differences that are inaudible, and caring about thresholds as to when distortions and deviations *just become audible*. Why all of a sudden are audible deviations from flat in a loudspeaker (what should be per your measurements) something you or we aren't supposed to care about? Especially, again, given the point of that speaker design being they *should not* have those audible deviations if the manufacturer's claims for flat response are correct.

In fact, given your care in being precise in rendering DAC and amp measurements even when the sonic consequences are below audibility, so we can see the competence of the design and whether it's reached specs, it seems a similar concern would have carried over to testing loudspeakers. Even if the off-recomended-axis measurements you produced displayed deviations from flat that wouldn't be audible, they would still be measurable deviations, and don't we still care about measurable deviations from an equipment's claimed spec? To try to be as precise as possible it would still make sense to measure based on manufacturer-intended axis.

I'm just as puzzled as many here by this whole thing.

Having followed this thread I can't help but be left wondering at least somewhat about the reliability of the measurements in future reviews. Simply redoing the test would have been an obvious way to mitigate the concerns raised by a significant number of readers. Instead, you have taken the worst possible reading of these concerns waving them off with a "Why bother? You'll never be satisfied!" type of response. I think you could give your audience more credit. They are all expressing appreciation while telling you the problem they are seeing in the measurements, and telling you exactly what step would gain their trust in the measurement process.
 
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TimVG

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I'm not quite sure about this - I'm waiting for @amirm to confirm/deny. But, I believe the Klippel system while measuring in the nearfield, simulates the data as it would present itself in the farfield - so even if you are measuring at the tweeter axis instead of the actual acoustic center, in reality the data presented would only be 1 or 2° off. I'd still include the microphone calibration file though - why not try and make the data as good as it can be with the available means.

FYI - for those of you who really really want to have a KH80 retested, I contacted Klippel. For the price of €1188,00 + shipping they'll happily test any speaker. I'm happy to donate a KH80 and put in an hour of time to pack and ship it, but I'm not going to spend any money on it.
 

aarons915

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I think people just pissed Amir off to be honest, he has made changes to future tests after this one including making sure drive levels are to CTA-2034. In the LS50 review I mentioned I had never seen a 5k peak and he mentioned that he noticed that as well and remeasured it because of that, so he's not as hard-headed as it may seem in this thread. This review can be ignored if you want, I personally think we should just delete it entirely and move on.
 

Vintage57

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They’re his marbles and he’s going to have his game his way.

As a committed donor I would have been happier if Amirm would have taken the high road. This may serve as a bad precedent.

Disclosure. I’m a Neumann owner and somewhat of a brand champion.
 

Ilkless

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I'm not quite sure about this - I'm waiting for @amirm to confirm/deny. But, I believe the Klippel system while measuring in the nearfield, simulates the data as it would present itself in the farfield - so even if you are measuring at the tweeter axis instead of the actual acoustic center, in reality the data presented would only be 1 or 2° off. I'd still include the microphone calibration file though - why not try and make the data as good as it can be with the available means.

FYI - for those of you who really really want to have a KH80 retested, I contacted Klippel. For the price of €1188,00 + shipping they'll happily test any speaker. I'm happy to donate a KH80 and put in an hour of time to pack and ship it, but I'm not going to spend any money on it.
Here's a potential way to get NFS graphs from Klippel themselves for free (if I read correctly).

http://www.klippel.de/fileadmin/kli...cture/Sound Quality of Audio Systems 2020.pdf

They have an upcoming lecture series. As part of the lecture series, Klippel is holding a house party (see second page) the night of 9th March. If I'm reading it correctly, one neither needs to register for the lecture nor pay to attend the party, and one can just bring loudspeakers to be measured (presumably NFS). Perhaps a member living nearby can try to ask and attend. Even if they don't own one, I'd be willing to chip in for shipping by a member who has one to a Dresden member.
 

hardisj

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Here's a potential way to get NFS graphs from Klippel themselves for free (if I read correctly).

http://www.klippel.de/fileadmin/klippel/Bilder/Education/3day_Lecture/Sound Quality of Audio Systems 2020.pdf

They have an upcoming lecture series. As part of the lecture series, Klippel is holding a house party (see second page) the night of 9th March. If I'm reading it correctly, one neither needs to register for the lecture nor pay to attend the party, and one can just bring loudspeakers to be measured (presumably NFS). Perhaps a member living nearby can try to ask and attend. Even if they don't own one, I'd be willing to chip in for shipping by a member who has one to a Dresden member.

If you guys can wait a month or two or three I can test this speaker for you as well. I'll be using Klippel products for my site (in my sig) for testing. Though, I won't have the NFS, I will have the ability to measure at varying degrees of axis and post-process the data. At least on par with what other publications are providing and probably better, if I say so myself because I'll be providing distortion testing as well (assuming donors of products don't mind). I'm hoping to build a dedicated test room in my attic space but that will depend on what the price for the Klippel is going to run me. So, like I said, I'm happy to do some further testing if you guys can wait and I can afford to get the Klippel modules I'll need to do what I want.

If ya'll want to carry this discussion to a different thread let's take it to this thread about my site; just make sure to quote me from this post so it makes sense:
https://www.audiosciencereview.com/forum/index.php?threads/erinsaudiocorner.11219/
 
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