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SPL vs. SQ

Wes

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#1
What difference in SQ is needed to overcome a 0.5 dB mismatch in SPL between 2 components?
 

RayDunzl

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#3
1591902168395.png
 
OP
Wes

Wes

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Thread Starter #6
It is oft cited on here that a 0.1 dB mismatch in SPL will bias listening tests in favor of the louder device chain.

But the converse does not seem to have been addressed, hence my query
 

Theriverlethe

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#7
It is oft cited on here that a 0.1 dB mismatch in SPL will bias listening tests in favor of the louder device chain.

But the converse does not seem to have been addressed, hence my query
The converse is unquantifiable, so you’re better off volume-matching. Because of equal loudness curves, a slight increase in SPL will result in “harder-hitting bass” and/or “airier highs” while not being obviously louder.
 

pozz

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#8
It is oft cited on here that a 0.1 dB mismatch in SPL will bias listening tests in favor of the louder device chain.

But the converse does not seem to have been addressed, hence my query
Not exactly. It's a criterion for level-matching the output from the compared sources, measured with a multimeter or analyzer, and based on the just-noticable difference (JND) in psychoacoustics. It not exactly that value because it varies depending on signal type/bandwidth, frequency, with the extremes needing more difference, and personal hearing.

These are graphs for listening tests made with test tones below.

1591918272556.png

https://www.frontiersin.org/articles/10.3389/fnagi.2011.00006/full

Incidentally, they confirm something Olive and Toole have pointed out many times in their studies using trained listeners: "The high performers [i.e., those who could discriminate the smallest differences] were less variable in their performance than the low performers." But notice that by the time you hit 2dB of SPL (intensity) difference nearly 80% of young listeners (average 24 years old) were able to tell.

Anyway, to get away from all those complexities just match test tones within 0.1dB electrically at the outputs.
 

Inner Space

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#9
But surely the OP asks a different question: if an obviously "good" speaker is compared with an obviously "bad" speaker at a precise level match, we can expect (hope?) that the "good" speaker will be preferred. But if the "bad" speaker is inched upward in level, beyond the JND, will it now automatically be preferred? Or is there something about the "good" and "bad" speakers' respective SQs that will allow the original preference to survive the new amplitude mismatch? And if so, what?
 

Bear123

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#11

pozz

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#12
But surely the OP asks a different question: if an obviously "good" speaker is compared with an obviously "bad" speaker at a precise level match, we can expect (hope?) that the "good" speaker will be preferred. But if the "bad" speaker is inched upward in level, beyond the JND, will it now automatically be preferred? Or is there something about the "good" and "bad" speakers' respective SQs that will allow the original preference to survive the new amplitude mismatch? And if so, what?
Speakers are:
  • Not flat in frequency response.
  • Have different sound power (total radiation around the speaker).
  • Have different sensitivity to amps.
  • Are of different sizes.
  • May be positioned differently during comparisons (distances, angles).
When comparing electronics using the same speakers, you can use a test tone and volt meter because FR is flat. When comparing different speakers, you have to level-match as best you can using test signals like bandpassed noise or pink noise with a sound level meter.

On top of that there are differences in hearing and so on, and you may not be sitting in the same position.

What ends up being the most important after the level-matching effort's been made is the general, broad spectral tendencies in the speakers' curves. Does that make sense?

Edit: Typo.
 
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Inner Space

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#14
What ends up being the most important after the level-matching effort's been made is the general, broad spectral tendencies in the speakers' curves. Does that make sense?
Not totally. Can you imagine a non-level-matched comparison between equipment where the quieter presentation is preferred by a significant margin? If so, why?
 

RayDunzl

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#17
It is oft cited on here that a 0.1 dB mismatch in SPL will bias listening tests in favor of the louder device chain.
What I think I think:

If two devices "sound the same", but one is played 0.1dB louder than the other, it may be selected (in otherwise blind listening) as "better".


But the converse does not seem to have been addressed, hence my query
The converse is if two devices "sound the same", but one is played 0.1dB softer than the other, it may be selected (in otherwise blind listening) as "worse".

Any questions?

Speakers?

They don't sound the same, unless they are the same, then the above applies.

Any more questions?
 

RayDunzl

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#18
Can you imagine a non-level-matched comparison between equipment where the quieter presentation is preferred by a significant margin? If so, why?
Yes.

I can turn my Radio Shack Multiband Patrolman Radio up louder than you might expect.

I would certainly prefer to listen to my main system at that or even lesser levels.

edit: I forgot to answer "why?".
 
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Wes

Wes

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Thread Starter #19
But surely the OP asks a different question: if an obviously "good" speaker is compared with an obviously "bad" speaker at a precise level match, we can expect (hope?) that the "good" speaker will be preferred. But if the "bad" speaker is inched upward in level, beyond the JND, will it now automatically be preferred? Or is there something about the "good" and "bad" speakers' respective SQs that will allow the original preference to survive the new amplitude mismatch? And if so, what?
exactly

or simplify it for amps to reduce the "multi-dimensional suck factor" that all speakers have
 
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pozz

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#20
Not totally. Can you imagine a non-level-matched comparison between equipment where the quieter presentation is preferred by a significant margin? If so, why?
Me too. So level matching is important mostly (only?) where the SQs under test are pre-judged to be similar?
There is no parameter called "sound quality", but let's simplify it to how loud a speaker can play and its tone, tone just meaning that parts of the FR are different.

I think one of the confusions might be to do with the otherwise straightforward words "quieter" and "louder". These are always frequency-specific when it comes to audio:
1591933604628.png

These are the last three speakers measured by Amir. I got the FR data from @edechamps' Open Loudspeaker Explorer.

Notice that the graph has matched the on-axis FR for all three at 300Hz. So, ostensibly, if you used a 300Hz test tone and matched the SPL, you would get that FR (ignoring the effects of the room). Looking just at 20Hz to 300Hz, what you'll find is that you might like the blue because it's loudest, or because of the emphasis on bass. Or you might like the orange even though it's quieter because that range is flatter and more even. Or you might like red because it reaches deeper and has output at 50Hz stronger than the other two.

So, to summarize, if the tone is exactly the same, assuming it's not pushed beyond what it can handle, the louder speaker will win.

If the tone is different then it's not completely certain what will win.

For electronics, which will 99 times out of 100 have the same flat FR, the louder component will win.
 
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