I have a value (it's an audio signal) between 0 and 1 that I can multiply a signal in decibels by to get the amplitude I want.

I want to use this number to change the ampitude of a signal however that signal is an absolute value. Is there a way I can do a calculation on the ratio signalso that I can multiply it with a signal using absolute values and get the correct reduction in audio? I want to keep all signals as audio signals too.

I want to use this number to change the ampitude of a signal however that signal is an absolute value.  Is there a way I can do a calculation on the ratio signalso that I can multiply it with a signal using absolute values and get the correct reduction in audio?  I want to keep all signals as audio signals too.

ratios-for-gain-between-decibels-and-absolute-values

> I have a value (it's an audio signal) between 0 and 1 that I can

> multiply a signal in decibels by to get the amplitude I want.

> I want to use this number to change the ampitude of a signal however

> that signal is an absolute value. Is there a way I can do a

> calculation on the ratio signalso that I can multiply it with a

> signal using absolute values and get the correct reduction in audio?

> I want to keep all signals as audio signals too.

Alistair wrote:
> I have a value (it's an audio signal) between 0 and 1 that I can
> multiply a signal in decibels by to get the amplitude I want.
>
> I want to use this number to change the ampitude of a signal however
> that signal is an absolute value.  Is there a way I can do a
> calculation on the ratio signalso that I can multiply it with a
> signal using absolute values and get the correct reduction in audio?
> I want to keep all signals as audio signals too.
>
> Does that make sense?  Possibly not.

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How about this, if I have the gain reduction in dB how can I effect an absolute value with the correct gain reduction?

Quote: Al wrote on Tue, 21 February 2006 13:03

----------------------------------------------------

> How about this, if I have the gain reduction in dB how can I effect an absolute value with the correct gain reduction?

What do you mean "doesn't seem to work"? It works the way I expect it to. If I want to go from 0db to -6db, I would change my amplitude from 1.0 to 0.5. And that's what dbtoa (and dbtoa~) do for me.

Quote: Al wrote on Tue, 21 February 2006 13:03
----------------------------------------------------
> No, doesn't seem to work.
>
> How about this, if I have the gain reduction in dB how can I effect an absolute value with the correct gain reduction?
----------------------------------------------------

What do you mean "doesn't seem to work"?  It works the way I expect it to.  If I want to go from 0db to -6db, I would change my amplitude from 1.0 to 0.5.  And that's what dbtoa (and dbtoa~) do for me.

I don't understand why it woulden't work ? it's no matter if the signal is absolute value or not, in multiplication ?

No, I'm trying to apply that reduction in gain to another signal which is an absolute value. I need to know how the ratios would work in relation to each other. For instance I have a number between 0 and 1 that I can multiply the dB by to create a new amplitude, what calculation would I need to do to correct that ratio to work with an absolute signal?

It's quite possible that I'm missing something obvious or I'm doing something totally wrong but it seems to me there should be some logical relationship between the two ratios.

No, I'm trying to apply that reduction in gain to another signal which is an absolute value.  I need to know how the ratios would work in relation to each other.  For instance I have a number between 0 and 1 that I can multiply the dB by to create a new amplitude, what calculation would I need to do to correct that ratio to work with an absolute signal?

It's quite possible that I'm missing something obvious or I'm doing something totally wrong but it seems to me there should be some logical relationship between the two ratios.


Hold on, I think I may have missed something. Just trying soemthing out.

Hold on, I think I may have missed something.  Just trying soemthing out.


I've cracked it, sorry for talking nonsense there.

I'm not fully sure of what you are aiming at, but if you want to use 

the loudness of one signal to control loudness of another signal, you 

could check out tl.balance~ from tl.objects:

I'm not fully sure of what you are aiming at, but if you want to use  
the loudness of one signal to control loudness of another signal, you  
could check out tl.balance~ from tl.objects:

ratios for gain between decibels and absolute values