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Human ears more sensitive than measuring instruments

Frank Dernie

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#21
Well if the measuring instrument has to be 10x better than what you are measuring and you are using ears to listen to a speaker with a distortion level of -50dB then perhaps the best you could hope to hear is around -40dB distortion level???
 

DonH56

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#22
-40 dB = 1 %, for decades the definition of "high fidelity". We are generally more sensitive to variations in amplitude over frequency (frequency response) than distortion, perhaps because FR variations tend to be much larger in the real world.

IME distortion, noise, amplitude, phase, etc. are all readily measured to far better than we can discern through hearing. What gets harder to measure, or at least to set up a measurement methodology for, are things like imaging and sound stage (e.g. depth). Readily measurable but you have to determine phase and such among the sources (speakers) and correlate that to a sense of width and depth. Not horribly difficult IIRC (been many years since I did it) but a little tricky to process the data for presentation. You need/want to be able to say "OK, change the amplitude/phase/delay in that speaker by X amount and the image shifts by Y." When I did it (back in college again, where all the fun was :) ) I used a series of numbered markers on the floor and listeners would record the markers where they heard the sound. By adjusting delay and volume you could move the sound around, left to right and front to back.
 
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amirm

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#24
0.3 dB? How far down can measuring gear measure to? Amir? 0.03 dB? I'm not a measuring guru but input would be appreciated.
You mean with respect to amplitude of frequency response? If so, yes, it is about 0.03 dB. But this is across 1 microvolt to whopping 160 volts and full bandwidth. For 20 to 20 kHz the accuracy improves to 0.008 dB for lower than 20 volt input. This is far, far more accurate than our hearing thresholds.
 

MZKM

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#25
This is far, far more accurate than our hearing thresholds.
Which is stated to be ~0.2dB.

https://www.audiocheck.net/blindtests_level.php?lvl=0.2v

You can change to other levels as well. Even a -1dB change (~20% wattage reduction) is not noticeable if not immediately listening for it (if I lowered the volume of your system by 1dB and you came back the next day, you wouldn’t notice).
 

sergeauckland

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#26
Which is stated to be ~0.2dB.

https://www.audiocheck.net/blindtests_level.php?lvl=0.2v

You can change to other levels as well. Even a -1dB change (~20% wattage reduction) is not noticeable if not immediately listening for it (if I lowered the volume of your system by 1dB and you came back the next day, you wouldn’t notice).
My preamp's volume control goes is reasonably accurate 1dB steps, and on music I generally don't notice 1dB reduction even when I know I've just done it!

S
 

Kal Rubinson

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#28
What's flat for me isn't necessarily for you.
Puts the 1dB cable induced differences (if they exist) into perspective...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4123622/
But that is irrelevant. Sure, we have unique and constant HRTFs (and central processes, as well) but, because they are fixed, their filter on a frequency-flat signal is the same as it is on a stage band or a string quartet. Flat has no meaning except as a reference.
 

andreasmaaan

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#30
What's flat for me isn't necessarily for you.
Puts the 1dB cable induced differences (if they exist) into perspective...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4123622/
View attachment 24194
That's not quite right IMHO. Each person's pinnae puts the input through its own specific filter, but that's the same filter that every sound that person hears goes through. So in this respect, flat is the same for everyone.*

*Headphones are a special case of course.
 

PierreV

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#31
That's not quite right IMHO. Each person's pinnae puts the input through its own specific filter, but that's the same filter that every sound that person hears goes through. So in this respect, flat is the same for everyone.*

*Headphones are a special case of course.
Yes, I have to agree with you and @Kal Rubinson - the reference flat wasn't a good example.
 

Sal1950

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#32
What's flat for me isn't necessarily for you.
Irrelevant. When you hear live music, you hear it in the special way your ears let you.
When you listen to recorded music you do the same.
A accurate system sounds accurate to everyone.
 

digicidal

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#33
Would agree with the flat-is-flat aspect... however, considering that almost nothing is truly flat... the graph would clearly indicate where subtle peaks or dips would be more dramatic (and potentially unpleasant) to one listener than another. Without a similar graph of a subjective reviewer's hearing - there's no way to know where they're "naturally attenuated" (and without your own, no way to compare the two to have an idea if you would hear the sound similarly).

Sure is nice to have objective measurements in such cases. ;)
 

JohnYang1997

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#35
Would agree with the flat-is-flat aspect... however, considering that almost nothing is truly flat... the graph would clearly indicate where subtle peaks or dips would be more dramatic (and potentially unpleasant) to one listener than another. Without a similar graph of a subjective reviewer's hearing - there's no way to know where they're "naturally attenuated" (and without your own, no way to compare the two to have an idea if you would hear the sound similarly).

Sure is nice to have objective measurements in such cases. ;)
Human's hearing is isolated/ independent from reproduction. When people go to concert the performance itself is the same, the human perception is irrelevant from objective reproduction. Subjective preference however can be very different.
 

solderdude

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#36
Who listens with their ears (only)?
I do sometimes, both with speakers and headphones. It helps me to concentrate on the music more (sounds better to me)

What I do find is that when watching a music video and watching the artists play live I don't care about the sound quality and even on a TV the sound is totally convincing. When I close my eyes and listen to the music only I find the sound quality crap and can't discriminate instruments as well as when looking.
I guess this is the same effect as following 1 person in conversation while others around you are also talking. Record and reproduce it and it is very hard to follow the conversation.

Brains are funny devices and so easy to fool as well.
 

Sal1950

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#39
Is that Marty Feldman or the hoarder on American Pickers? God, the programs I watch.:p
You mean "mole man", the guy with all those underground rooms, etc?
I hate to admit knowing this. :eek:
 

Wombat

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#40
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