The Logic Off Topic list

A theoretical question here:

If you have two stereo audio-files, both 16 bit - 44,1khz, and digitally mix
them together you still only get a stereo audiofile 16 bit - 44,1khz.

Is there then a theoretical degration of the sound quality?

--
Arvid Solvang
http://www.viagram.no/privat/arvid/
ICQ: 13008461

>>Arvid Solvang wrote:
>>
>> If you have two stereo audio-files, both 16 bit - 44,1khz, and digitally
>>mix them together you still only get a stereo audiofile 16 bit - 44,1khz.
>>
>> Is there then a theoretical degration of the sound quality?
>
>From: Bobo Mark <mark4@...>
>If u don't any processing like EQ,compression.  It should no degration.

But wouldn't one track that has all these bits have higher resolution than
two tracks having the same amount of bits?

PS. I know that there are no audible differents I'm just not sure how this
work theoreticly.

--
Arvid Solvang
http://www.viagram.no/privat/arvid/
ICQ: 13008461

Arvid Solvang wrote:
> 
> From: "Arvid Solvang" <arvid@...>
> 
> A theoretical question here:
> 
> If you have two stereo audio-files, both 16 bit - 44,1khz, and digitally mix
> them together you still only get a stereo audiofile 16 bit - 44,1khz.
> 
> Is there then a theoretical degration of the sound quality?
> 

If u don't any processing like EQ,compression.  It should no degration.
-- 
Regards
Bobo mark

-----------------
Producer/Engineer
Artechnica Sound

Arvid,

My understanding was that the relative bit rate would decrease as tracks are
added together, if they are not output at a higher bit rate.  For example if
you mixed 2 matching sine waves, each at 16 bit and zero db, the resultant
amplitude and dynamic range would exceed the ability of the 16 bits to
represent it accurately.  So when they are output at 16 bits instead of
having a sine wave with double the amplitude (and dynamic range) you have
one with an identical amplitude to the first 2 sine waves.  So therefore the
relative dynamic range and bit depth was decreased during mixing to 16 bits.
This is the same whether it is output as a file or to a D/A.  This is a
reason why intenal processing of 32 bits is superior;  it allows the dynamic
range to be greater and more accurate during computation.  So when multiple
audio tracks are mixed they have a much lower increase in amplitude than 2
identical sine waves but it still  adds up and thus the output needs to be
reduced when going from the internal (and usually greater) bit depth to the
output bit depth.

Now for a disclaimer.  I do not know how accurate my interpretation of the
situation is.  I could be totally wrong here....

Lars H


> From: "Arvid Solvang" <arvid@...>
>
> >>Arvid Solvang wrote:
> >>
> >> If you have two stereo audio-files, both 16 bit - 44,1khz, and
digitally
> >>mix them together you still only get a stereo audiofile 16 bit -
44,1khz.

> >>
> >> Is there then a theoretical degration of the sound quality?
> >
> >From: Bobo Mark <mark4@...>
> >If u don't any processing like EQ,compression.  It should no degration.
>
> But wouldn't one track that has all these bits have higher resolution than
> two tracks having the same amount of bits?
>
> PS. I know that there are no audible differents I'm just not sure how this
> work theoreticly.
>
> --
> Arvid Solvang
> http://www.viagram.no/privat/arvid/
> ICQ: 13008461
>
> --------------------------- ONElist Sponsor

Thinking about it more I just want to make a possible correction.



> From: "Pamela or/and Lars" <pollen@...>
>
>
> Arvid,
>
> My understanding was that the relative bit rate would decrease as tracks
are
> added together, if they are not output at a higher bit rate.  For example
if
> you mixed 2 matching sine waves, each at 16 bit and zero db, the resultant
> amplitude and dynamic range would exceed the ability of the 16 bits to
> represent it accurately.  So when they are output at 16 bits instead of
> having a sine wave with double the amplitude (and dynamic range)

I don't think the dynamic range would double because of the amount of energy
to double the db's I think is in the order of 10 times.  So although the
dynamic range would be higher it would not be double.  I think.

you have
> one with an identical amplitude to the first 2 sine waves.  So therefore
the
> relative dynamic range and bit depth was decreased during mixing to 16
bits.
> This is the same whether it is output as a file or to a D/A.  This is a
> reason why intenal processing of 32 bits is superior;  it allows the
dynamic
> range to be greater and more accurate during computation.  So when
multiple
> audio tracks are mixed they have a much lower increase in amplitude than 2
> identical sine waves but it still  adds up and thus the output needs to be
> reduced when going from the internal (and usually greater) bit depth to
the
> output bit depth.
>
> Now for a disclaimer.  I do not know how accurate my interpretation of the
> situation is.  I could be totally wrong here....
>
> Lars H
>
>
> > From: "Arvid Solvang" <arvid@...>
> >
> > >>Arvid Solvang wrote:
> > >>
> > >> If you have two stereo audio-files, both 16 bit - 44,1khz, and
> digitally
> > >>mix them together you still only get a stereo audiofile 16 bit -
> 44,1khz.
> > >>
> > >> Is there then a theoretical degration of the sound quality?
> > >
> > >From: Bobo Mark <mark4@...>
> > >If u don't any processing like EQ,compression.  It should no degration.
> >
> > But wouldn't one track that has all these bits have higher resolution
than
> > two tracks having the same amount of bits?
> >
> > PS. I know that there are no audible differents I'm just not sure how
this

> > work theoreticly.
> >
> > --
> > Arvid Solvang
> > http://www.viagram.no/privat/arvid/
> > ICQ: 13008461
> >
> > --------------------------- ONElist Sponsor
>
>

No!
When you digitally mix 2 audiofiles, there is no quality loss, as it is only a
multiplication of values
Cheers,
Gilles

Arvid Solvang wrote:

> If you have two stereo audio-files, both 16 bit - 44,1khz, and digitally mix
> them together you still only get a stereo audiofile 16 bit - 44,1khz.
>
> Is there then a theoretical degration of the sound quality?
>