Robbie Busting Audio Myths at CanJam NYC 2024

[IAtaman]

https://physics.stackexchange.com/questions/110540/how-loud-is-the-thermal-motion-of-air-molecules
I don't know enough to check it, but sources are cited putting it at -20 to -30 dB SPL depending on assumptions, so the Microsoft anechoic chamber isn't far off. Between that and the point where the atmosphere starts clipping we have the dynamic range of the atmosphere, around 220dB.

... atmosphere starts clipping ...

Oh wow. Never thought of that. So obvious when someone points it out - there is indeed a maximum pressure air can transfer.

From Wiki:
While 1 atm (194 dB peak or 191 dB SPL)[11][12] is the largest pressure variation an undistorted sound wave can have in Earth's atmosphere (i. e., if the thermodynamic properties of the air are disregarded; in reality, the sound waves become progressively non-linear starting over 150 dB), larger sound waves can be present in other atmospheres or other media, such as underwater or through the Earth.

 

[somebodyelse]

It's the low pressure side of the wave that has a hard limit - it can't drop below zero. The high side can go higher. For comparison, analysis of the SLS launch compared to the Saturn V:
https://pubs.aip.org/asa/jel/articl...nd-power-of-NASA-s-lunar-rockets-Space-Launch

 

[MaxwellsEq]

I give

It's the low pressure side of the wave that has a hard limit - it can't drop below zero. The high side can go higher. For comparison, analysis of the SLS launch compared to the Saturn V:
https://pubs.aip.org/asa/jel/articl...nd-power-of-NASA-s-lunar-rockets-Space-Launch

Wow, fascinating paper, thanks! A new rabbit hole beckons.

 

[AdrianusG]

Sure, In any case if you have the option like at HDTracks, don't pay more for 24/192 files. You'll never hear a difference unless
one of the files has been purposely manipulated to sound different and milk your wallet.

Hi Sal,

In how far can we trust this web side (HDTracks), as in, are their High Res files really High Res, and not up-scaled CD'quality, is there a way to check this?
I once bought an album through them (Lee Morgan - The Sidewinder 24-96) and sure enough when played with JRiver it says it's correct.

Here's the thing , if for instance i Rip a CD with DB Poweramp i could Rip it to 24-96, you would of course not get any extra information or better fidelity, just a much larger file, but JRiver would still display it as 24-96 as well, so....

 

[IAtaman]

Hi Sal,

In how far can we trust this web side (HDTracks), as in, are their High Res files really High Res, and not up-scaled CD'quality, is there a way to check this?
I once bought an album through them (Lee Morgan - The Sidewinder 24-96) and sure enough when played with JRiver it says it's correct.

Here's the thing , if for instance i Rip a CD with DB Poweramp i could Rip it to 24-96, you would of course not get any extra information or better fidelity, just a much larger file, but JRiver would still display it as 24-96 as well, so....

Well, if you can not tell by hearing, why pay more to 24-96?

 

[AdrianusG]

Well, if you can not tell by hearing, why pay more to 24-96?

I know I know, but still would like to know how to check whether High Res is really High Res.

 

[IAtaman]

I know I know, but still would like to know how to check whether High Res is really High Res.

One way might be to check for ultrasonic content in a simple audio software like Audacity I suppose. If the file has ultrasonic content, then it might be likely due to the fact that its sampled at > 44.1K.

 

[MaxwellsEq]

I know I know, but still would like to know how to check whether High Res is really High Res.

Use SOX.