Neumann KH80 DSP Monitor Measurements #3

[amirm]

Is it a crazy suggestion, @amirm, you mention the room temperature in your reviews goig forward? This could prevent future discussions about intersample differences from a trusted measurement/speaker.

I will once the weather gets cooler. But I guess I can do it now as well...

 

[amirm]

amir-when you did the listening test originally was it straight in from the garage to the desk to listen or were the speakers already indoors for some time? No reason why the listening test would be any more particularly unreliable if it had been inside for a while I suppose?

It went from Garage to listening in about 10 minutes probably. So it was still cold at the start I guess.

 

[amirm]

If you decide to test one in the next six months let me know, if I love them I will keep them but guitar center has an extended 180 day return policy, so whatever happens if at some point you do want to, 14 pounds shouldn’t be too bad on my wallet.

You mean KH120? If so, it would be good to test it.

 

[Pepperjack]

Yea

You mean KH120? If so, it would be good to test it.

yea, two are on the truck to me now and one is back ordered (they are grade 1 open box from guitar center, so if being open box matters there is nothing I can do about that) but whenever you decide you want just let me know, no rush to get it done since the extended return is so long (unless I keep them of course then it doesn’t matter at all) but just preferably wait to let me know until your about ready to do it if you decide you want to.

 

[Kachda]

I am interested in getting KH80 for desktop use in an apartment. Can I use any small sub to reduce the lower frequency strain on the small 4" woofers, or do they only work with neumann subs ? I am not really interested in having a big expensive subwoofer since in an apartment I will keep the gain on the sub very low, and the main purpose will be to have some bottom end while letting the woofer of the KH80 only handle 80hz and above

 

[jhaider]

with the way Neumann has done the KH 80 and KH 750 DSP, this might be one of the only "ideal subwoofers" we can actually go out and buy? It's also absolutely the easiest one to integrate. And this also makes that system, by far, the best performance-per-dollar speaker ASR has ever tested?

Not necessarily, or even likely. Unless Neumann knows both where the KH80 and KH750DSP are placed relative to each other and the listening position (assuming 1-2 subs) and the acoustic characteristics of the room, they can't hope to integrate the two. I suspect those "integration" graphs were taken with monitor on top of sub in an anechoic chamber, which has little relevance to use in a real room. No matter what subs you use, clean integration still requires a lot of measurements and simulation or trial-and-error.

Still, I admit the idea of making a “modern KEF 107” (really more like "105 design, 107 form factor) or "B&W Matrix 802" by sticking a pair of KH80 atop beautifully finished stout bass bins with a crossover in the 200Hz range is appealing to me as a comparatively (!) low-budget SOTA stereo or LCR speaker. One could even go 4-way (a la Revel Salon2) by adding a midbass coupler at the top of the woofer box, with appropriate filtering.

 

[bigguyca]

@amirm

In case no one has posted this on this tread before, this is a detailed document from Neumann concerning loudspeaker measurements. The link downloads a 19 page .pdf.

https://www.google.com/url?sa=t&rct...950/download&usg=AOvVaw1zfo0PqTVQe30XBOo-uJmz

Pages 15 -16 describes multi-tone intermodulation distortions tests for loudspeakers, which are of course like the ones you already perform for electronics.

It would be really nice if you could run multi-tone IM tests on some of the loudspeakers you test.

 

[Sancus]

Not necessarily, or even likely. Unless Neumann knows both where the KH80 and KH750DSP are placed relative to each other and the listening position (assuming 1-2 subs) and the acoustic characteristics of the room, they can't hope to integrate the two.

The iPad app lets you set these things(relative distances of speakers, room dimensions and some basic details about positioning like near walls or not) and also offers an 8-band PEQ if you prefer to do it manually, so it should offer decent integration.

That said, Genelec's fully automated GLM system most likely does better, and the iPad requirement to work with Neumann stuff is seriously annoying.

 

[Typevii]

The iPad app lets you set these things(relative distances of speakers, room dimensions and some basic details about positioning like near walls or not) and also offers an 8-band PEQ if you prefer to do it manually, so it should offer decent integration.

That said, Genelec's fully automated GLM system most likely does better, and the iPad requirement to work with Neumann stuff is seriously annoying.

It also lets you select the 'type' of wall as well, soft (drywall) or solid (concrete/brick) for the sub, and distance to listener.

You can then edit the final results as needed manually if needed. (however, as has been noted, this is a real pain on the ipad using only the touch screen sliders to adjust values.)

 

[Music1969]

Wasn’t that done in the original review? Even though there might be a change in dips etc due to temperature, Is it unreasonable to expect the changes due to being off axis to remain within the same range of change, just based on the updated on axis performance? Or am I misunderstanding the original data?

amir-when you did the listening test originally was it straight in from the garage to the desk to listen or were the speakers already indoors for some time? No reason why the listening test would be any more particularly unreliable if it had been inside for a while I suppose?

I was talking about iLoud MTM

 

[amirm]

@amirm

In case no one has posted this on this tread before, this is a detailed document from Neumann concerning loudspeaker measurements. The link downloads a 19 page .pdf.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwii6pvficvqAhWfJzQIHdpID1sQFjADegQIBRAB&url=https://en-de.neumann.com/product_files/7950/download&usg=AOvVaw1zfo0PqTVQe30XBOo-uJmz

Pages 15 -16 describes multi-tone intermodulation distortions tests for loudspeakers, which are of course like the ones you already perform for electronics.

It would be really nice if you could run multi-tone IM tests on some of the loudspeakers you test.

I have started running this already: https://www.audiosciencereview.com/...olution-xt-6-speaker-review.14662/post-454599

But I need to do more work to refine it. Neumann is most likely using a very quiet anechoic chamber. My Audio Precision is quite loud which causes problems.

 

[jhaider]

The iPad app lets you set these things(relative distances of speakers, room dimensions and some basic details about positioning like near walls or not) and also offers an 8-band PEQ if you prefer to do it manually, so it should offer decent integration.

I’m beyond skeptical of any subwoofer integration approach that does not start with measurements in place.

 

[Sancus]

I’m beyond skeptical of any subwoofer integration approach that does not start with measurements in place.

That's fair, I haven't tried it with my Neumanns so no idea how well it works in practice. But I sort of doubt Neumann would use this method if it produces a terrible result, the performance of their stuff produces some level of trust. It would be cool if someone who does have one of the subs posted REW measurements of the combo to confirm, though!

Either way I certainly trust the GLM measurement methodology more, but ofc Genelec's subs are crazy expensive so I HOPE they integrate better...

 

[MZKM]

I have started running this already: https://www.audiosciencereview.com/...olution-xt-6-speaker-review.14662/post-454599

But I need to do more work to refine it. Neumann is most likely using a very quiet anechoic chamber. My Audio Precision is quite loud which causes problems.

How do you feel about Arcam‘s response that your 32Bit test has way too much high frequency content and is far from being representative of real music?

 

[amirm]

How do you feel about Arcam‘s response that your 32Bit test has way too much high frequency content and is far from being representative of real music?

How about I post what they wrote and my response to them:

I run this test per above because it is provided by Audio Precision so anyone with the same equipment can run it and results can be compared. The equal amplitude of the tones allows one at a glance to see if the frequency response is flat and the ratio of distortion to the tone.

As an interesting aside, when playing this signal, it sounds like an organ note. My wife said last night that it reminded me of the soundtrack of scary movies!

BTW there is real life content with extremely high amplitude high frequencies:

No one should design a system relying on what music/soundtrack to a movie looks like. Content looks like whatever it wants!

 

[ernestcarl]

If I don't turn on the space heater during winter, the basement room temperature sometimes goes to as low as 16 degrees celsius here where the Neumann's are sitting at... hmmmn. Also the sub is directly sitting on the floor, where it can get as cold as 14 to 10 degrees (when extremely cold)! Now, does this mean all my measurements done in the winter cannot be trusted? Well, it's probably a good thing that I wait for the ambient temperature to reach 21-22 degrees celsius now before doing most measurements.

Honestly, I am more concerned about my legs and hands feeling cold than warming up the speakers adequately for my ears' pleasure.

*It would be interesting to know how tropical or dessert hot climates affect speaker measurements. From the klippel graph it looks like just slight bass boost.

 

[ernestcarl]

Yep, same. I'd certainly heard about temperatures affecting woofers before, and I think that probably makes intuitive sense to most of us, but it was an issue of scale. I'd pretty much relegated temperature differences to the same mental space where I file the effects of burn-in on a woofer -- relevant only for measuring drivers outside a cabinet and with minimal effect on the primary audible factor of frequency response

Very clearly, that was a false equivalence!

This makes me wonder about wearing headphones outside during winter even more. I wear full-sized headphones during -20 to -30 degrees celsius winters here in Canada. At those temperatures, my critical listening/sensing faculties are all but somewhat numb anyway...

 

[thewas]

Sound & Recording uses a EIA426B spectrum based multitone measurement signal which drops its amplitude from 1 kHz to 10 kHz about 10 dB, which is closer to most musical content than constant amplitude one, but I can also understand if someone prefers the other one.

I have generated a similar signal that I use for my personal measurements, if someone wants it, just send me a PM, here an example measurement based on it:

 

[DualTriode]

Since the beginning of this speaker testing stuff in the garage in Washington State I have been concerned about the Humidity and temperature of the garage lab and the reflective concrete floor, gypboard walls and ceiling.



Sparky the cat has a lab near the coast in northern California. We are in between moving there and finishing up employment in the Sacramento Central Valley. When we make the trip to Sparky’s Lab the thermostat is set at 50 degrees and the humidity is damp.



For grins before turning up the heat I tested Frequency Response Impedance, phase and Theile Small Parameters of a JBL 2235H, JBL 2226H, JBL 2204H and several JBL compression drivers prior to turning up the heat. Everything was tested again in the morning after the heat was turned up overnight.



There was a huge difference in woofer resonance and TSP’s with the increase in temperature. The TSP’s were a complete moving target verses temperature confirmed over days. Temperature are part of the test conditions and are recorded in the book kept on my bench.



So no surprise that test results change with test conditions.



Thanks DT

 

[amirm]

Since the beginning of this speaker testing stuff in the garage in Washington State I have been concerned about the Humidity and temperature of the garage lab and the reflective concrete floor, gypboard walls and ceiling.

??? Reflections have no impact on the measurements since they are mathematically taken out of the measurements by using dual scans (and determining the direction of soundwaves).

And while outdoor winter humidity is on the high side due to rain, for the rest of the year we enjoy very low levels of it.