Should we (I) get into speaker testing & measurement

[amirm]

This Loudsoft system might be cheaper than Klippel. It presents data differently, but perhaps there is option to make H&K spinoramas
https://www.loudsoft.com/fine-rd/

It doesn't do anything that you can't do with a USB microphone and REW. It uses gating to eliminate reflections. This requires increasing the distance to reflection points by elevating speaker outside. And even then, you get almost no resolution below a few hundred hertz. It also provides no automation for measurements requiring the operator to handle and keep track of all the microphone movement in 3-d space.

 

[amirm]

It's somewhat ironic for a site called "Audio Science Review" to spend so much energy measuring things that make such little difference to what we actually hear......at least according to psychoacoustic science.

Well, energy is cheap in this case. It is my time. Speaker testing of the same level of quality retails for $100,000 when it is all said and done. My hands are tied behind my back in membership not wanting advertising and sponsorship. I can write a check for $40,000+ but that is still not enough.

The alternative of me sitting outside, putting a speaker on a tall pole, rotating it a few degrees at a time to measure and repeat all that at different height is just not something I want to spend my time on. It is rainy and cold here half the year and when it is nice and warm, I like to enjoy the outdoors than managing a measurement system.

In contrast, electronic measurements occurs in my lab which is a loft overlooking our living room. I can spend many hours on it without feeling like I am disengaging from family life.

So let me know what the suggestions are to move forward. Otherwise you are at the mercy of how much more money I can throw at this hobby....

 

[DDF]

It doesn't do anything that you can't do with a USB microphone and REW. It uses gating to eliminate reflections. This requires increasing the distance to reflection points by elevating speaker outside. And even then, you get almost no resolution below a few hundred hertz. It also provides no automation for measurements requiring the operator to handle and keep track of all the microphone movement in 3-d space.

Have you considered Benjamin's method of low frequency pre-emphasis to the stimulus and then high pass filtering the speaker impulse (1-1 compensation) to reduce the impulse length? You might be able to squeeze measurements into an available space. It won't get you the speed you're after though, but this could be one incremental step towards it.

 

[Absolute]

Yes, I have concluded and decided for you now. I need to see speaker information. Have you set-up a funding campaign yet?
Why shouldn't you monetize the site? The measurements speaks for themselves regardless. If you were to make a list of upcoming reviews before measuring them, we'd be able to see if there's a correlation between fishy measurements/sudden absence of them and advertising.

I see no obligation for you to dedicate your spare time to our amusement without ever being able to at least cover your expenses in your quest to entertain/educate us. If the advertisement would be audio-related and somewhat unobtrusive, I'd certainly wouldn't mind them.
Perhaps it could even be temporary in order to achieve the funding needed to buy the Klippel?

You could perhaps make old reviews a pay-to-read for a small amount to non-active users?

 

[watchnerd]

So let me know what the suggestions are to move forward. Otherwise you are at the mercy of how much more money I can throw at this hobby....

If capital to buy the fancy speaker test rig is the blocker, I'd lower the bar and just do in-room measurements.

It's a good place to start, to practice methodologies. We'll certainly learn something. It works well enough for Stereophile.

 

[amirm]

It's a good place to start, to practice methodologies. We'll certainly learn something. It works well enough for Stereophile.

JA measures them outdoor on his porch I think. And from what I recall, takes him a whole weekend to do.

 

[watchnerd]

JA measures them outdoor on his porch I think. And from what I recall, takes him a whole weekend to do.

He doesn't always measure outdoors.

Example:

Description:
Fig.1 TAD ME1, spatially averaged, 1/6-octave response in JA's listening room (red), and of Dynaudio Contour 20 (blue).

"Listening done, I measured the TAD's spatially averaged response in my room (footnote 2). The result is shown as the red trace in fig.1. The ME1's output gently slopes down in the lower midrange and bass, but, as noted above, there's useful low-frequency extension in-room down to 30Hz. The upper-frequency in-room response is superbly even, and while a gentle measured top-octave rolloff can be seen, I feel that this is actually more neutral in-room behavior, given the increased absorptivity of the room furnishings in the high treble.

The blue trace in fig.1 is the spatially averaged response of the Dynaudio Contour 20, which had impressed me when I reviewed it in May 2017 and wrote that it is indeed "a high-performance loudspeaker with a transparent sound." The Dynaudio's in-room response is not quite as even as the TAD's, and there's a little less energy in-room above 8kHz, but it's otherwise very similar. While the speakers are very different, other than both being stand-mounted speakers of similar size, I suspect that this is a case of convergent evolution."

Read more at https://www.stereophile.com/content...-john-atkinson-march-2018#XDxVokxQk3fwKbzi.99

In this case, not only does he measure the TAD in-room, but compares it to an earlier Dynaudio measurement taken almost a year earlier in the same room.

If it's good enough for JA to publish comparative in-room results for speakers, I don't see why it shouldn't be okay for ASR, too.

 

[watchnerd]

FWIW, I have a hell of a time using test tones at home, because they make my yell asking what the crazy noises are, wondering if something is broken.

So I have to wait until she leaves.

 

[amirm]

In this case, not only does he measure the TAD in-room, but compares it to an earlier Dynaudio measurement taken almost a year earlier in the same room.

That is the only thing that it is good for. Otherwise, you can't predict the sound you will get in your room with the same speaker.

 

[watchnerd]

That is the only thing that it is good for. Otherwise, you can't predict the sound you will get in your room with the same speaker.

Did you read his footnote on the methodology?

"Footnote 2: I average 20 1/6-octave–smoothed spectra, individually taken for the left and right speakers using an Earthworks QTC-40 microphone, SMUGSoftware's FuzzMeasure 3.0 program, and a 96kHz sample rate, in a rectangular grid 36" wide by 18" high and centered on the positions of my ears. This mostly eliminates the room acoustic's effects."


Read more at https://www.stereophile.com/content...-john-atkinson-march-2018#XEDMRd5wYOqQsr0D.99

 

[LeftCoastTim]

Did you read his footnote on the methodology?

"Footnote 2: I average 20 1/6-octave–smoothed spectra, individually taken for the left and right speakers using an Earthworks QTC-40 microphone, SMUGSoftware's FuzzMeasure 3.0 program, and a 96kHz sample rate, in a rectangular grid 36" wide by 18" high and centered on the positions of my ears. This mostly eliminates the room acoustic's effects."


Read more at https://www.stereophile.com/content...-john-atkinson-march-2018#XEDMRd5wYOqQsr0D.99

Huh? An audio engineer or readers of Toole’s book will observe that this method of measurement will have zero effect in eliminating the room acoustics.

 

[Blumlein 88]

JA measures them outdoor on his porch I think. And from what I recall, takes him a whole weekend to do.

You could build a floating speaker testing raft and use it on water. Gets you away from obstructions causing reflections.

 

[watchnerd]

Huh? An audio engineer or readers of Toole’s book will observe that this method of measurement will have zero effect in eliminating the room acoustics.

While I also find JA's logic weird, in my mind:

1. If all the speakers are measured in the same room at the same place in the same way, relative comparisons become possible, even if not as pure as an anechoic / Spinorama / Jupiter room set up

2. We all listen in real rooms, anyway, where results below Schroeder dominate, so anechoic results are only semi-applicable in real life, anyway.

3. I'd rather have some speaker measurements than zero

4. We're not trying to publish AES papers or do speaker design

Again, the limitations of in-room aren't stopping Stereophile from publishing in room measurements and I don't see them getting crap for doing so.

 

[amirm]

Did you read his footnote on the methodology?

"Footnote 2: I average 20 1/6-octave–smoothed spectra, individually taken for the left and right speakers using an Earthworks QTC-40 microphone, SMUGSoftware's FuzzMeasure 3.0 program, and a 96kHz sample rate, in a rectangular grid 36" wide by 18" high and centered on the positions of my ears. This mostly eliminates the room acoustic's effects."

That is a lot of manual work. JA gets paid to do this work. I don't.

And again, it has no predictive effect. The bass response for example, will not be representative and that accounts for a lot of speaker sound.

 

[watchnerd]

That is a lot of manual work. JA gets paid to do this work. I don't.

And again, it has no predictive effect. The bass response for example, will not be representative and that accounts for a lot of speaker sound.

So make it so you get paid?

And then hire some college intern if you don't want to do it yourself?

It seems like you have more of a passion to play with a fancy speaker testing rig than a passion to measure speakers by any means necessary.

Which is fine, but at least come to terms with that and be transparent if that's the conclusion you arrive at.

"Sorry guys, I have no interest in measuring outdoors / in a garage / on a pole / on a boat using typical labor intensive methods. If I can't fund a Klippel rig to make it easy, rapid, and entertaining for me, it's a non-starter."

And then kick off a Go Fund Me.

 

[amirm]

So make it so you get paid?

And then hire some college intern if you don't want to do it yourself?

It seems like you have more of a passion to play with a fancy speaker testing rig than a passion to measure speakers by any means necessary.

My "passion" is to generate data that is based on research to predict listener preference. That science is known. But the data essentially non-existent for speakers on the market.

DIY type methods like JA is deploying is not usable this way. It makes for busy work to sell magazines and such. But it has no value in my mind. I want someone to buy a speaker based on my measurements and have high probability of him liking it.

I also need to have high throughput just as I have with electronics. I can't move the needle testing 3 speakers a year. The automated system measures a speaker in less than hour and is all automated. So I could test a speaker and publish in a day like I am doing with electronics.

James at Audioholics has the best manual system to approximate the CEA-2034A/Harman system. If you are that anxious for data, follow his work. But note that he only reviews a few speakers a year per above. Here is a picture of his setup:

Which limits him in testing any speaker that is too heavy.

 

[watchnerd]

My "passion" is to generate data that is based on research to predict listener preference. That science is known. But the data essentially non-existent for speakers on the market.

DIY type methods like JA is deploying is not usable this way. It makes for busy work to sell magazines and such. But it has no value in my mind. I want someone to buy a speaker based on my measurements and have high probability of him liking it.

I also need to have high throughput just as I have with electronics. I can't move the needle testing 3 speakers a year. The automated system measures a speaker in less than hour and is all automated. So I could test a speaker and publish in a day like I am doing with electronics.

James at Audioholics has the best manual system to approximate the CEA-2034A/Harman system. If you are that anxious for data, follow his work. But note that he only reviews a few speakers a year per above. Here is a picture of his setup:

Which limits him in testing any speaker that is too heavy.

Okay, sounds like you've decided it's a non-starter, then.

 

[watchnerd]

Or.....

Just be blunt.

Klippel or nothing.

And then figure out a way to have the site pay for it.

This thread has been going on since June.

It's been getting a bit dead-horsey....

 

[Hugo9000]

Thanks for the references. Unfortunately all of these schemes require work, manual intervention to get reasonable results. Add this to manual measurements at multiple locations and you have a long process for measurements.

The "innovation" I am suggesting here through the use of Klippel system is what makes this whole thing work: a fast measurement system that doesn't require anechoic chamber, produces processed graphs compliant with standard/Harman, ready to be interpreted. This is what can enable me to grind through many speaker measurements. What others do is fine for one review every other month but not the style of work and rate of publication we have here (daily reviews).

It is not just the low frequency response but the rest of the measurements in order to arrive at the right data set to then predict listener preference.

That can be done using semi-manual system with an automated turntable and manual or automated microphone placement. Harman measures 70 points for example. But even this setup goes well above $10,000 and still not optimal.

To get the high throughput that I have now on electronics, an automated system that performs all of these measurements quickly and far more accurately is needed. Otherwise the scattering of speaker measurements is already out there.

In a nutshell, we are doing first-class evaluation of electronics. Do we want to invest in first-class evaluation of speakers? One where the prediction results for listener preference is almost a given?

I have looked at all those options. Still a lot of money (thousands for the turntable alone) and lots of manual work. People who do that put out a review every other month. My goal is to be as speedy as my electronics measurement. The Klippel system measures a speaker in as little as 20 minutes with little intervention. I don't know that we can move the mark in the industry by measuring 4 or 5 speakers a year.

I think it's clear from Amir's posts throughout this thread that he wants to have an impact, producing rapid high-quality measurements to significantly increase the information out there for consumers and audio enthusiasts. He wants to set the bar higher, with both quality of data and quantity.

 

[watchnerd]

I think it's clear from Amir's posts throughout this thread that he wants to have an impact, producing rapid high-quality measurements to significantly increase the information out there for consumers and audio enthusiasts. He wants to set the bar higher, with both quality of data and quantity.

That's fine.

Then stop debating and start moving towards monetization, if that's what it takes to fund the equipment.

75% of the site said they want it.

Seems like it's time to fish or cut bait.