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Neumann KH150

I did some reading (KH 80 DSP review, the 8030c review and the KH150 review)...and I tried to EQ the Neumann tonight...getting in closer to 'direct sound' and then comparing further away with the sum of all reflective surfaces.

With the Genelec 8030c, I could correlate an improvement when EQ'ing (as per Amir's recommendations), near and far field.
With the Neumann, in far field, not so much. If anything it made the speakers sound too bright.

My room is not treated.

Second test: tonight I put some damping material here and there and that improved things. More work needed.

But the conclusions for me was the difference EQ'ing achieved, and not achieved, between the Genelecs and the Neumanns.

Good lesson learned!
Yes, EQ cannot correct everything, which filters did you use on the Neumann?
 
Yes, EQ cannot correct everything, which filters did you use on the Neumann?
Bass = -2 db
Midbass = - 2 db
High = 0

I listening to varied material and those settings seem to work best. I don't even use the EQ on the RME as it sounds overall just very very good.
 
Bass = -2 db
Midbass = - 2 db
High = 0

I listening to varied material and those settings seem to work best. I don't even use the EQ on the RME as it sounds overall just very very good.
That is more (primitive) room/boundary correction though and cannot be compared to the EQs from Amirs measurements or even better your own ones at the listening position. In the end what matters is that you are satisfied with it.
 
No, they literally do not. I will keep repeating this. The 150s have a kink in the SP that the 120 IIs do not have anywhere near as severely (note how much narrower it is), and the average SP slope is quite a bit shallower (0.2dB/oct might not sound like a lot, but that's in effect a roughly 1dB high shelf from 500hz-16KHz). I've heard them both too, if you know what to listen for it isn't subtle.

View attachment 418712View attachment 418713
Those differences are not audible.
 
That is more (primitive) room/boundary correction though and cannot be compared to the EQs from Amirs measurements or even better your own ones at the listening position. In the end what matters is that you are satisfied with it.
Primitive It is for now. More time to use automated room correction software in the future!
 
Who makes the KH150 woofer?
1000064850.jpg
 
SoundonSound have a detailed review that I read a few days ago. Here is an excerpt:

The KH150 bass/mid driver is a newly developed unit that Neumann say was specifically engineered to offer a significant improvement in distortion, low‑frequency bandwidth and maximum level. In particular, the driver’s motor system is designed to offer extreme linearity and low distortion over extended diaphragm displacement. By way of illustration, a typical off‑the shelf 165mm bass/mid driver will offer between ±6mm and ±8mm of linear diaphragm travel. The KH150 driver, say Neumann, offers ±12mm. This was achieved through intense FEA modelling of the magnet system and diaphragm suspension components, and the use of a variable voice‑coil winding profile technique. The latter is particularly unusual. Forward of the voice coil and magnet system, the KH150 bass/mid driver employs a paper diaphragm and dust cap, paired with a rubber roll surround. The relatively low crossover frequency will help with bass/mid diaphragm design and optimisation, because it makes the diaphragm break‑up characteristics and surround termination characteristics a little less critical. Even so, Neumann say that the particular demands placed on the surround by the driver’s very high linear displacement make its optimisation extremely complex.

Finally on the bass/mid driver, its custom‑designed die‑cast aluminium chassis forms a structural element of the enclosure front panel — recovering the structural panel weakness that results from the big hole the driver demands.
 
I think Neumann make their own drivers, but they possibly have them made by a third party, to their specification. Either way, I don't think they are "off the shelf" items that are used elsewhere.
They usually order from Tymphany/Peerless.
 
SoundonSound have a detailed review that I read a few days ago. Here is an excerpt:

The KH150 bass/mid driver is a newly developed unit that Neumann say was specifically engineered to offer a significant improvement in distortion, low‑frequency bandwidth and maximum level. In particular, the driver’s motor system is designed to offer extreme linearity and low distortion over extended diaphragm displacement. By way of illustration, a typical off‑the shelf 165mm bass/mid driver will offer between ±6mm and ±8mm of linear diaphragm travel. The KH150 driver, say Neumann, offers ±12mm. This was achieved through intense FEA modelling of the magnet system and diaphragm suspension components, and the use of a variable voice‑coil winding profile technique. The latter is particularly unusual. Forward of the voice coil and magnet system, the KH150 bass/mid driver employs a paper diaphragm and dust cap, paired with a rubber roll surround. The relatively low crossover frequency will help with bass/mid diaphragm design and optimisation, because it makes the diaphragm break‑up characteristics and surround termination characteristics a little less critical. Even so, Neumann say that the particular demands placed on the surround by the driver’s very high linear displacement make its optimisation extremely complex.

Finally on the bass/mid driver, its custom‑designed die‑cast aluminium chassis forms a structural element of the enclosure front panel — recovering the structural panel weakness that results from the big hole the driver demands.

I came across another article that went into some detail about the woofer; it doesn't mention who actually makes it though:
https://musicandmiscellany.com/2023/01/03/secrets-of-the-neumann-kh150/

It looks like that article is actually the same author, Phil Ward, as the SOS review. :)
 
Who makes the KH150 woofer? View attachment 419266
Peerless/Tymphany, but it's Neumann's own design and not an off the shelf part; the closest resemblance is the HDS-P830875. I'd imagine the KH120 II is similar, but shrunk.

The tweeter they use is also a Peerless made part based I believe on the DA25BG08 platform (albeit with a unique metal/fabric dual-layer diaphragm) but they have used a similar SEAS-made part in the past. The KH310's woofer is also completely custom with no similar off-the-shelf part - it seems to be a mix of different parts from various lines along with Neumann's own designing. The KH420 uses a PHL-made woofer, albeit again not an off-the-shelf part (based on the 4311, if memory serves, but far from identical). The mid dome is made by I believe Peerless India (separate from Tymphany, if memory serves?).
 
I would appreciate your source for this. I thought it was more like 10 ms. thanks
I learned that Haas/Precedence effect is generally 20-30ms in Audio Engineering II back in the 90's, and by twisting knobs on a Lexicon PCM42, TC 2290 and Eventide H8000 and listening :) . Also mentioned here https://en.wikipedia.org/wiki/Precedence_effect

"Clicks" can be detected much shorter than 20ms, but generally speaking, anything "Musical" is 20+ms to be heard as 2 separate sounds (generally across speakers and hard panned, used as "time-based panning" to a degree). Less than 20ms and we hear them as a single event w/o a detectable "Slap back" effect.

Room reflections that fall into that range (less than approx 20' total distance for ~ 20ms) will also be smeared together with the direct sound by the same phenomenon. In my room - I absorb first reflections (4" + 1" gap on the ceiling made the biggest difference in my smallish room) so this is not really an issue for me...
 
I learned that Haas/Precedence effect is generally 20-30ms in Audio Engineering II back in the 90's, and by twisting knobs on a Lexicon PCM42, TC 2290 and Eventide H8000 and listening :) . Also mentioned here https://en.wikipedia.org/wiki/Precedence_effect

"Clicks" can be detected much shorter than 20ms, but generally speaking, anything "Musical" is 20+ms to be heard as 2 separate sounds (generally across speakers and hard panned, used as "time-based panning" to a degree). Less than 20ms and we hear them as a single event w/o a detectable "Slap back" effect.

Room reflections that fall into that range (less than approx 20' total distance for ~ 20ms) will also be smeared together with the direct sound by the same phenomenon. In my room - I absorb first reflections (4" + 1" gap on the ceiling made the biggest difference in my smallish room) so this is not really an issue for me...
I thought that it is 6 or 8 ms.
 
I thought that it is 6 or 8 ms.
A little OT from the thread - but I posted a link above - and what I mentioned about my own experience in production. Clicks can be detected at shorter than 20ms, but music will not be heard as an "Echo" (discrete sound) under 20ms or so. These offsets WILL have a huge effect on soundstage even with a few ms (one side delayed) when used for sound field placement (production tricks) - but comes with the compromise of good mono compatibility (ends up comb filtered when folded to mono for obvious reasons)...

If you have a DAW, you can play with this on your own using your own ears, and see how sound field placement changes with a dual-mono signal with delay on one side (irrespective of amplitude within reason) until the offsets surpass the Haas threshold, and then are heard as a hard-panned echo.
 
A little OT from the thread - but I posted a link above - and what I mentioned about my own experience in production. Clicks can be detected at shorter than 20ms, but music will not be heard as an "Echo" (discrete sound) under 20ms or so. These offsets WILL have a huge effect on soundstage even with a few ms (one side delayed) when used for sound field placement (production tricks) - but comes with the compromise of good mono compatibility (ends up comb filtered when folded to mono for obvious reasons)...

If you have a DAW, you can play with this on your own using your own ears, and see how sound field placement changes with a dual-mono signal with delay on one side (irrespective of amplitude within reason) until the offsets surpass the Haas threshold, and then are heard as a hard-panned echo.
From Gemini......
The human ear is remarkably sensitive to the timing differences between sounds arriving at each ear.

  • Detectable Delay: Studies have shown that humans can typically detect delays as small as half a millisecond (0.5 milliseconds).


  • Factors Influencing Detection:
    • Sound Frequency: High-frequency sounds are generally more easily localized than low-frequency sounds.
    • Sound Intensity: Louder sounds may be easier to localize than quieter sounds.
    • Individual Variation: There can be significant individual differences in the ability to detect small time delays.
 
From Gemini......
The human ear is remarkably sensitive to the timing differences between sounds arriving at each ear.

  • Detectable Delay: Studies have shown that humans can typically detect delays as small as half a millisecond (0.5 milliseconds).


  • Factors Influencing Detection:
    • Sound Frequency: High-frequency sounds are generally more easily localized than low-frequency sounds.
    • Sound Intensity: Louder sounds may be easier to localize than quieter sounds.
    • Individual Variation: There can be significant individual differences in the ability to detect small time delays.
Yes - Being a drummer of 40+ years and being into DAW's for 25 years - I am very aware of human sensitivity to latency/feel. If I had to track drums with 10+ms of latency - I'd go mad!

And I'm not disagreeing that we can RESOLVE very tiny timing differences down to micro-seconds - of course we can! This is how we sense direction and space. This is not referring to the Haas effect - but does absolutely impact the ear-brain system with regard to localization. All of these minute timing differences (well below Haas/20ms) will be "heard" as a single event by the Ear/Brain. This is why early reflections "blur" the direct sound as they are UNDER the Haas threshold, and are "Heard" as a single event - and imperfect reflections below 20ms (and unavoidable comb filtering) confuse the ear/brain system WRT localization.

The goal is to get first reflections / early reflections OUTSIDE of the Haas effect threshold where they will appear as two separate sounds (generally > 20ms, or a reflection distance of around 20') and our ear/brain will easily "hear" those separately from the direct sound - making our sensitive localization to of all the minute timing stuff you mentioned much cleaner. So if the first reflections are greatly attenuated via acoustic treatment, in most rooms the next set of reflections will be outside the 20ms threshold.

To test the Haas effect yourself - fire up a DAW and place a stereo delay on a track - a mono track will be most revealing. Increase the delay on ONE SIDE by 1ms at a time and see how it initially affects soundfield placement like panning (even though relative volumes are identical!). Once you get around 20ms or so on one side, the delay will no longer act as a soundfield placement effect, but will morph into a short slap-back echo we clearly "hear" as a separate echo event.

This is what I'm referring to - and early reflections that fall under that threshold will inevitably smear the direct sound - especially when the speaker has significant directivity error and the room will allow early reflections of sufficient amplitude back to your ear in under 20ms - and you will hear it as a single event along with the direct sound.

Going back to my initial comment on the tropic - Treating first reflections (especially the ceiling) will negate a lot of the issues with off-axis sound and directivity error (as was mentioned to be an issue for the KH150 in "live" rooms at mid-to-far field MLP's). Even Erin and Amir recommend ceiling and floor treatment for speakers with vertical directivity error (a thin carpet no so much - I use 4" 703 + 1" gap on the ceiling)...

:cool:
 
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