[NUT-devel] [nut]: r613 - docs/nutissues.txt

[Måns Rullgård]

Rich Felker <dalias at aerifal.cx> writes:

> On Wed, Feb 13, 2008 at 04:48:42AM +0100, Michael Niedermayer wrote:
>> > I'm against the useless physical units and denominator. Just the
>> > ratios of the positions to one another matter; the whole thing is
>> > scale-invariant for all practical purposes. 
>> 
>> Well, it is not scale-invariant, yeah the world sucks ...
>> The speed of sound is not infinite and more distant speakers will have
>> their signal hit the listener later. That causes a phase shift and could
>> change a 2*sin() to 0*sin().
>
> In the range of sane distances, is this really an issue? I'm thinking
> anywhere from headphones to theaters. Somehow I suspect the speed of
> sound and the frequencies involved make it irrelevant but I didn't
> work out the math.

Audible wavelengths range roughly from 20m to 0.02m.  If there is
coherence between the channels, interference effects are readily
observed moving around a room with two speakers.

Any half-decent surround sound system has adjustable delays per
channel to allow compensating for speaker placement.

>> So a system of a speaker at 1m and one at 2m will would sound
>> different from one with a speaker at 1km and 2km (with the volume
>> turned up sufficiently)
>
> WOW I want those speakers! :)
>
>> Iam not saying that there is any need or sense to store this nor
>> that i would know what a decoder would do with that information,
>> but i do know copper purity counters will prefer NUT over other
>> formats if the distance is stored.
>
> Well I would like to see some mathematical/physical reason that it's
> potentially useful rather than the opinions of people who pay for
> solid-gold *digital* audio cables to give their sound "more body"...

Agree.

-- 
Måns Rullgård
mans at mansr.com