Yes, I am aware of that.
We can read, Richard. We don't need a flashing neon sign to know that the word is "unweighted."
I don't know why you didn't just quote the entire sentence, which included the A-weighted requirement as well. This would have been useful for ACTUAL COMPARISON.
This is the complete sentence:
"The A/D converter will have a dynamic range of not less than 115 dB unweighted, 117 dB A-weighted."
And I note that the difference in their unweighted requirement and their A-weighted requirement is just 2dB. Are you trying to say that a 2dB difference makes all the difference in the world? So much so that you had to leave the A-weighted figure out and hang the neon sign on unweighted?
Do you have a problem with their A-weighted requirement of 117dB?
As I said, very strange.
se
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Audible thresholds under WHAT CONDITIONS?
Sitting in a quiet room listening to silence, or while ACTUALLY LISTENING TO MUSIC?
se
Remember that with A weighting, the level at 20 Hz, could be +50dB louder
http://upload.wikimedia.org/wikiped...g/400px-Acoustic_weighting_curves_(1).svg.png
Yes.
But it has been Richard who has been holding up the IASA as a beacon of authority. So I thought it was rather strange that he would quote only a partial sentence from their requirements, leaving out their A-weighted requirement, and hanging a neon sign on "unweighted" when there is only a 2dB difference between the IASA's unweighted requirement and their A-weighted requirement.
See what I'm saying?
se
Bill Waslo's tracks with the Brahms lullaby are rather germane if embarrassing to some. I think it was at -65dB. I'm sure there's creative excuses about that example as well.
Audio DiffMaker example files
yes, that is the gist of it. the rest is just noise.
The acoustic range needed has also been researched and I'll put up some, later. its based on the lowest loudness curves and listening room curves. But, it turns out we need high resolution (ie >16 bits) after all if we want to make sure our distribution channel, does not add more noise than the rest of the chain (120db is 20 bits).
Ref also might be found here: "Noise: Methods for estimating Detectability and Threshold" by Stuart, AES Vol 42 issue 3 pp 124-140 March 1994.
and "Dynamic Range Issues in the Modern Digital Audio Envirnment' By Fielder, L. AES Vol 43 issue 5 pp 322-339, May 1995
I wont pick out my favorite points because it will start another round of crazed rants.
THx-RNMarsh
I already answered that --- it is unwgted and ADC/DAC are often weighted specs. see what I am saying?
THx-RNMarsh
Scott,
No need to put words in my mouth, I can speak for myself. Big Hint; when listening to music not everyone sits in the same place!
Dick,
When you place pearls before swine, they don't just ignore them they slip on them. You have put forth among all this noise some of the most important missed issues.
(For those wondering, there ain't no such thing as digital! Well almost none.)
ES
I'll pass on this discussion, but in parting please reconcile all these references to the fact that recordings like the Reference Recordings Kodo Drummers CD which has peak levels set for the big Taiko drums is unlistenable (to me) in a normal room environment because some of the rest is buried at 40-60dB lower. This is at 16/44.1.
Sorry Ed that slipped out, I do mean to leave the -140dB distortion stuff lie. BTW have you done the marching band test?
I see starting another twenty questions?
I measured my listening room late last night --- 22dB. Would that help you?
[I can easily hear sounds some dB's below that background.]
Its 70 degrees F and sunny and it's California. Be back later.
THx-RNMarsh
And we all know what the distortion levels for ADC/DAC conversions are at these levels.
I do not know the answer, Scott can probably calculate this in his head,
If you take a sine wave , ADC (-50dBc) convert it to digital using your best ADI chip (16/44.1K), then pipe (I2S) to the best ADI 16/44.1K DAC, measure THD, what #'s are we talking here, I am guessing >0.1-1% THD (IHF limits?)
And the difference between IASA's unweighted requirement and their A-weighted requirement is 2dB. Are you claiming that this 2dB difference makes all the difference in the world?
And if ADC/DAC specs are often given A-weighted, then why NOT quote IASA's A-weighted requirement?
Leaving out the IASA's 2dB difference A-weighted requirement, when you yourself say ADC/DAC specs are often given as A-weighted, then hanging a neon sign on "unweighted" makes absolutely no sense.
se
Yes..... and so I would say three things.... listen to the music/sound at original performed level (louder, probably), listen in a quieter room/location and use 24 bit system. If they also make your drummers in 24 bit.
THx-RNMarsh
Ah more words.
Why don't you try the simple experiment of using a voltmeter to set a 50 hertz tone at a moderate to loud level into a single loudspeaker and then add a 5000 hertz tone and see at what level it can be perceived?
I suggest using two signal sources to reduce the confounders.
This is the usual suggested test that has nothing to do with the context of listening to music. How about seeing how much masking a 10Hz tone does to a 5kHz tone?
The question with music generating nothing above 50Hz what makes the 5000Hz tone? I know the 100th harmonic distortion.
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So listening at an average 85 dB level (too loud for me) part of the music is still not much above the room noise level. Turn the TV down until you can easily hear it but miss lots of conversation, that's the effect.
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