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POLL: Should Amir purchase additional software add-ons for Klippel NFS?

Should Amir purchase additional software add-ons for Klippel NFS, in order to measure more data?


  • Total voters
    81
  • Poll closed .
Wow, they charge as much as they can.
Yes, like 10K USD + shipping? + applicable duty? and taxes?. That's minimum ~400 people sending in $25.00 each. Plus the expense of the actual Klippel System.
 
Yes, like 10K USD + shipping? + applicable duty? and taxes?. That's minimum ~400 people sending in $25.00 each. Plus the expense of the actual Klippel System.

Pigs might fly. Oops.

And let's not mention the $100K bit.
 
I would like to see it, but I don’t believe it’s a necessity. There are workarounds if a speaker doesn’t get loud enough (e.g., reduce listening distance). There are no workarounds if it has terrible imaging and poor directivity.

What I care more about:

  • Testing sensitivity at 2.83Vrms, so many false/misleading specs, I mentioned elsewhere that Klipsch’s R/RP models are all ~6dB lower than their stated sensitivity as they aren’t using anechoic sensitivity but some in-room parameter, yet they don’t disclose this.
  • Testing +/-3dB claims. Paradigm states for their $5000 95F towers that it’s +/-2dB from 37Hz-20kHz on-axis & +/-2dB from 37Hz-17kHz @ 30°...
    • Stereophile measurement (30° horizontal listening window):
      1215P95Ffig04.jpg
    • SoundStage/NRC (0/15°/30°):
      fr_on1530.gif
 
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I would like to see it, but I don’t believe it’s a necessity. There are workarounds if a speaker doesn’t get loud enough (e.g., reduce listening distance apart). There are no workarounds if it has terrible imaging and poor directivity.
Whatever happens the standard needs to be set before testing many more speakers. Set it soon ;)
 
Like I said in the other thread...

As much of a proponent I am for the extra data, I feel like the horse is being put in front of the carriage here. I think right now everyone needs to take a step back and just focus on one thing at a time. Let’s all get comfy with the spin data and methods before asking Amir for anything else and moving on to “bigger and better” things.

Just my $0.02 here.

(To be clear, if Amir already had the modules he needs then that’s one thing. But he doesn’t and it’s pretty clear that not all of the information regarding the spinorama data is fully comprehended by all parties just yet. No need to pile on other unknowns at this very moment if it also means another expenditure. I don’t see that as beneficial right now. Maybe down the line.)



And a side note: I've spent years testing. The one thing that pushed me to quit many times was the number people who would assume my time was at their command... as if I was working for them. Most of the community was fine. But those 5% of people really aggravated me. Speaking from that experience, I must say, even I am starting to get annoyed by all these threads and OT everywhere about what is and isn't provided. It seems to be pervasive in nearly every thread. We've all said our piece ... some of us multiple times now (myself included). I think enough is enough. This isn't me kissing up to Amir... he and I have already had our back and forth regarding his previous tests and his attitude. Maybe the mods can just do some massive cleanup and dump all the OT posts about the "extras" in to a separate thread until things cool down. Until then I think ol' Amir needs to just "tell it how it's gonna be" so we can move on until the time comes to need to care again.
 
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I would like to see it, but I don’t believe it’s a necessity. There are workarounds if a speaker doesn’t get loud enough (e.g., reduce listening distance). There are no workarounds if it has terrible imaging and poor directivity.

What I care more about:

  • Testing sensitivity at 2.83Vrms, so many false/misleading specs, I mentioned elsewhere that Klipsch’s R/RP models are all ~6dB lower than their stated sensitivity as they aren’t using anechoic sensitivity but some in-room parameter, yet they don’t disclose this.
  • Testing +/-3dB claims. Paradigm states for their $5000 95F towers that it’s +/-2dB from 37Hz-20kHz on-axis & +/-2dB from 37Hz-17kHz @ 30°...
    • Stereophile measurement (30° horizontal listening window):
      1215P95Ffig04.jpg
    • SoundStage/NRC (0/15°/30°):
      fr_on1530.gif

It could be kind of fun as a side experiment to add see how much smoothing is required to reach a manufacturer's ±3 dB claim. I feel like 1/3rd octave is probably what a lot of them use, though I don't know if even that would be enough for the paradigm measurements above...
 
I'm kind of uncomfortable with the idea of suggesting that Amir should put more into this project than he already has.

That said, it seems to me like a thorough investigation of output capabilities is fertile ground for improving our understanding of speaker preferences and settling some audiophile debates. I simply don't believe that the spinorama tells the whole story when it comes to dynamics, headroom, behavior under a range of SPL, etc..
 
All this is a waste of time.
There is no need to buy any optional module
Amir: return the Klippel NFS.
The solution: pay Vincent Brient, Paul McGowan, Ted Smith , John Kenny and Michael Lavorgna. Your "ears" will have all the answers we need.

PS: I voted yes.
 
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And a side note: I've spent years testing. The one thing that pushed me to quit many times was the number people who would assume my time was at their command... as if I was working for them. Most of the community was fine. But those 5% of people really aggravated me.

Indeed.
Reminds me of why I stopped coaching youth sports some years ago. The presumptiousness exhibited as par for the course became too much.
Here's the whistle...all yours.

The criticism/complaints to thank you/appreciation ratio became way to high. Yes...it mattered.

Input, even strongly worded, is one thing...Iron sharpens iron and all that...and God knows we have a LOT of very capable and qualified members go at it with each other and with Amir...but this speaker thing just seems...i don't know...different for some reason.

I hope it settles down soon.
 
I voted indifferent. In Olive's study where they came up with the regression model for using the Spinorama to predict listener preference they stated that the model accounted for 99% of the variance in preference ratings. Remember the first, more controlled test with 13 bookshelf speakers had a .995 correlation, the .86 that is often cited is based on less stringent tests over many months and were therefore harder to control. So while distortion is interesting and we want to keep it low, this is another study that didn't show it to be important in preference.

I think common sense is all that is needed when talking distortion, compression, max SPL, etc. If you know you like to rock out at 100+ db, don't buy a monitor with a 4" woofer and if you listen to Jazz at 75 db, then a pair of Salon 2 are probably overkill.
 
I voted indifferent. In Olive's study where they came up with the regression model for using the Spinorama to predict listener preference they stated that the model accounted for 99% of the variance in preference ratings. Remember the first, more controlled test with 13 bookshelf speakers had a .995 correlation, the .86 that is often cited is based on less stringent tests over many months and were therefore harder to control. So while distortion is interesting and we want to keep it low, this is another study that didn't show it to be important in preference.

In Olive's study I doubt they drove the speakers at high levels, because that's not the point of the study. The goal of the study was to evaluate loudspeaker preference with the loudspeakers running within their limits. I don't think that study has any relevance when it comes to evaluating max SPL. These are two different, completely orthogonal dimensions. They're both important - though I do agree max SPL is the least important of the two.

I think common sense is all that is needed when talking distortion, compression, max SPL, etc. If you know you like to rock out at 100+ db, don't buy a monitor with a 4" woofer and if you listen to Jazz at 75 db, then a pair of Salon 2 are probably overkill.

Sure, but then there are some manufacturers who claim they are able to achieve high SPL in small form factors. We'll never know if they're right until we test these claims. For all you know, you might end up buying a large, expensive speaker "just to be safe", but if you had measurements you would realize that a cheaper speaker that's half the size would do just as well as far as max SPL is concerned.
 
https://www.soundstagesolo.com/index.php/features/181-how-to-read-our-headphone-measurements

Distortion

1580485891536.png



The chart above shows how the total harmonic distortion (THD) of a headphone varies with frequency, and at two different levels. Both of these levels are loud; 90dBA (measured with pink noise from my Clio 10 FW audio analyzer) is about as loud as I can stand to listen, while 100dBA is really louder than anyone should listen. But I’ve found these two levels are what “separate the men from the boys” in headphones, so to speak. Pretty much any headphones can play at 80dBA with no significant distortion. If headphones start to distort (usually in the bass) at levels above about 5% at 90dBA, you’ll probably notice that at loud levels. If they distort noticeably at only 100dBA, which is uncomfortably loud anyway, I don’t hold it much against them -- but if they don’t distort at 100dBA, which many headphones do not, then I give them extra credit for having robust drivers.

It’s important to remember here that while 0.5% THD is a commonly accepted threshold of audible amplifier distortion at 1kHz, the commonly accepted threshold for subwoofer distortion audibility is 10% THD. So if a headphone has 5% THD at 50Hz, it’s probably not a big deal.

The importance of harmonic distortion in headphones is usually vastly overstated. As you can derive from looking at my distortion charts, distortion normally becomes significant only at loud levels. At normal listening levels, it’s almost always insignificant because it’s occurring at levels perhaps 60dB below the material you’re listening to -- the equivalent of someone lightly whispering from a few feet away when your stereo is cranked.

In “The Correlation Between Distortion Audibility and Listener Preference in Headphones,” a 2014 Audio Engineering Society paper by Steve Temme, Sean Olive, Steve Tatarunis, Todd Welti, and Elisabeth McMullin, the researchers found that while listeners did single out one pair of headphones from the five tested as having excessive distortion, “The results from the listening tests indicated that listeners had difficulty reliably discriminating among the different headphones even though the distortion measurements indicated there were quantitative differences among them in terms of measured THD, IMD [intermodulation distortion], multitone and non-coherent distortion measured with music.”


Ok. The quoted section above is all based on headphone testing. Still, I think the logic applies to loudspeakers.

Also, I like the analogy he gives here. And while 60dB down is about 0.10% distortion and would be logically impossible to hear, 10% distortion is about 20dB down. That could be something along the lines of you jamming out to a broad spectrum song and having your wife hollering at you from the other room. Do you hear her?... aside from selective hearing, sometimes you don't. And if you were to measure 10% THD most likely that would be a mecahnical issue that would likely be clearly audible and would also show up in a frequency response sweep (as long as the MLS length were long enough to highlight the issue).

Anyway... I think considering how the percentages of distortion equate to a difference in the signal to the distortion level (% vs dB) is a good way to sensibly enter this argument of what is necessary and what isn't. I remember once reading a quote on the matter that "distortion isn't audible until it is". I realize that seems passive but I think it holds a lot of weight. Typically when I hear distortion it's been due to: electrical clipping of the signal, port noise, ringing of a driver playing past it's intended range (think: 6.5" midwoofer playing up to 8khz), or mechanically pushing a driver past it's limits (exceeding xmax).

I think distortion data is nice to have. But again, at this point I would put more stock in to making sure Amir can deliver quality and repeatable spinorama data first before asking him to pile on additional tests and potentially suffer the quality/accuracy of it all. Maybe we are only a couple months out from distortion data. I just don't think we are ready for that at *this* very moment as it seems Amir is still somewhat in the early stages of his testing.
 
In Olive's study I doubt they drove the speakers at high levels, because that's not the point of the study. The goal of the study was to evaluate loudspeaker preference with the loudspeakers running within their limits. I don't think that study has any relevance when it comes to evaluating max SPL. These are two different, completely orthogonal dimensions. They're both important - though I do agree max SPL is the least important of the two.

I think Harman typically runs their tests at 80-85db so no, not super loud but in line with where most people listen to music. I wasn't saying they were trying to evaluate max SPL, just that the frequency response is the only thing that has been shown to matter. There aren't any conclusive studies on the audibility of distortion and at what levels so I'm not sure how measuring it is going to tell us much.

Sure, but then there are some manufacturers who claim they are able to achieve high SPL in small form factors. We'll never know if they're right until we test these claims. For all you know, you might end up buying a large, expensive speaker "just to be safe", but if you had measurements you would realize that a cheaper speaker that's half the size would do just as well as far as max SPL is concerned.

That's true but I would say you can safely ignore most marketing and use common sense when deciding how big or how many woofers you need based on your own SPL habits. The current tests that run speakers around 85 db @ 1 meter would already be over 90 db in room with a stereo pair playing, so as long as distortion looks ok there, it will be good enough for 99% of listeners I would say.
 
I think Harman typically runs their tests at 80-85db so no, not super loud but in line with where most people listen to music.

It also depends on distance, though. There's quite a bit of difference between 80-85 dB at 1 meter for nearfield listening versus 8+ meters for filling a large living room.

There aren't any conclusive studies on the audibility of distortion and at what levels so I'm not sure how measuring it is going to tell us much.

I would expect there to be a threshold where the distortion from the loudspeaker skyrockets (much like amps), i.e. clipping, and that would be a good indicator of its max SPL. In fact I believe it's precisely this threshold that existing speaker measurement standards aim to determine.

use common sense

Appeals to common sense usually do not end well on a website that has "science" in its title. I don't want "common sense", I want facts, empirical data, measurements, and hard numbers.
 
It also depends on distance, though. There's quite a bit of difference between 80-85 dB at 1 meter for nearfield listening versus 8+ meters for filling a large living room.



I would expect there to be a threshold where the distortion from the loudspeaker skyrockets (much like amps), i.e. clipping, and that would be a good indicator of its max SPL. In fact I believe it's precisely this threshold that existing speaker measurement standards aim to determine.



Appeals to common sense usually do not end well on a website that has "science" in its title. I don't want "common sense", I want facts, empirical data, measurements, and hard numbers.

That may be true but that would only be at/near mechanical failure based on my testing experience. Even this 2.5" midrange driver with sensitivity in the upper 80's didn't show significant distortion ramp in my intermittent testing at 90/96/102dB @ 1m equivalent. 102dB full-range on a 2.5 midrange with no filter applied is quite a stress-test case, indeed.

https://web.archive.org/web/20180408035730/http://medleysmusings.com/afgb25



Maybe this actually proves your point, though; that you want this kind of testing to separate the men from the boys, so to speak. Still, I think asking a speaker to do 100dB full range at the typical living/movie room distance from speaker at 6-12 feet then that's the extreme end and I haven't personally seen a case where any of my test units have shown a significant spike in distortion profiles at pretty extreme output levels.



Here's the pictures: 90, 96, 102dB respectively:
gb25 90db.png


gb25 96db.png


gb25 102db.png
 
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