MS->LR conversion: why does order matter with gain?

MS->LR conversion: why does order matter with gain?

[Jeff Learman]

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I'm converting mid-side to LR.  Originally I used this:

sox $MS $LR gain -0.5 : remix -m 1,2 1,2i

but found that the result does not have an important property of mid-side:
when summed to mono, the effect does not cancel out.
I changed it to this:

sox $MS $LR remix -m 1,2 1,2i : gain -0.5

and it works as expected.  Why is there a difference?  Note that there is
no clipping going on in either case.  My intuition says that MS->LR is
linear, so gain applied before or after should have the same effect.

Thanks!
Jeff

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Re: MS->LR conversion: why does order matter with gain?

[Jeff Learman]

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Well I bet I didn't really mean to use negative gain!  But I think that
shouldn't affect the question.

On Sat, 30 May 2020 at 14:46, Jeff Learman <jjlearman@gmail.com> wrote:

> I'm converting mid-side to LR.  Originally I used this:
>
> sox $MS $LR gain -0.5 : remix -m 1,2 1,2i
>
> but found that the result does not have an important property of mid-side:
> when summed to mono, the effect does not cancel out.
> I changed it to this:
>
> sox $MS $LR remix -m 1,2 1,2i : gain -0.5
>
> and it works as expected.  Why is there a difference?  Note that there is
> no clipping going on in either case.  My intuition says that MS->LR is
> linear, so gain applied before or after should have the same effect.
>
> Thanks!
> Jeff
>
>

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Re: MS->LR conversion: why does order matter with gain?

[Jeff Learman]

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Never mind!  Colon abuse!  I meant to chain effects but instead I used
multiple effect chains.

On Sat, 30 May 2020 at 14:52, Jeff Learman <jjlearman@gmail.com> wrote:

> Well I bet I didn't really mean to use negative gain!  But I think that
> shouldn't affect the question.
>
> On Sat, 30 May 2020 at 14:46, Jeff Learman <jjlearman@gmail.com> wrote:
>
>> I'm converting mid-side to LR.  Originally I used this:
>>
>> sox $MS $LR gain -0.5 : remix -m 1,2 1,2i
>>
>> but found that the result does not have an important property of
>> mid-side: when summed to mono, the effect does not cancel out.
>> I changed it to this:
>>
>> sox $MS $LR remix -m 1,2 1,2i : gain -0.5
>>
>> and it works as expected.  Why is there a difference?  Note that there is
>> no clipping going on in either case.  My intuition says that MS->LR is
>> linear, so gain applied before or after should have the same effect.
>>
>> Thanks!
>> Jeff
>>
>>

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