Re: [Phys-L] decibels

[brian whatcott <betwys1@sbcglobal.net>]

On 5/1/2019 11:49 AM, Scott Orshan
wrote about the anechoic chamber at Bell Labs.

I could have used one of these in establishing the
radial accuracy of a sound direction finding and
elevation system ('SAZEL') I have been rigging to
throw some light on the mysterious booms which
happen periodically here.

Which reminded me...
> On 4/29/2019 6:20 PM, Anthony Lapinski wrote:
> > A student sent me this short article about the world's quietest room:
> >
> > www.smithsonianmag.com/smart-news/earths-quietest-place-will-drive-you-crazy-in-45-minutes-180948160/
> >
> > Anyone ever been in a room like this?
> >
> > And what do negative decibels mean? The "threshhold of hearing" (10^-12 W/m2)
> > corresponds to 0 dB. So a sound quieter than this (say, - 20 dB) has an
> > even lower intensity (10^-14 W/m2)? Is there a lower limit?
> >
> > How does this work with volume control knobs on stereo systems?
I missed the question on volume control potentiometers.
The potentiometer still in use with audio equipment has
??what is called a logarithmic taper. It is more accurate
??to describe it as non-linear. This spreads perceived
volume change more equally across the control's range
??rather than cramping it mostly into the first third
of its angular range.