Forums > MaxMSP

### average˜

Feb 02 2009 | 9:39 am

Feb 02 2009 | 5:52 pm

Regarding rms, I can’t find a reference that gives values for sin/saw waves, so I’m not sure if max is doing it wrong/differently than you’d expect.

As far as an auto level match, take the averages of signals A and B and then divide average B by average A. Multiply the actual A signal by the product of that division. This will make A match the average level of B.

A more interesting way to do this would be to average the two averages to find the mean level between the signals, and then bring BOTH inputs to that level via the division method, rather than one to the other.

p.s. throw an abs~ pre the input of average~ to make your stuff work in positive values.

Feb 03 2009 | 9:43 am

hi jack,

the problem is that average~ gives a right rms value
for the sine wave (0.707) and wrong rms values for other
waveshapes (for example 0.46 circa for saw~ and so on)…
So it would be difficult to take averages of two different
signals.
So how to take a right average to make the operation
you wrote?

thanks
fv

Il giorno 02/feb/09, alle ore 18:52, Jack ha scritto:

>
> Regarding rms, I can’t find a reference that gives values for sin/
> saw waves, so I’m not sure if max is doing it wrong/differently
> than you’d expect.
>
> As far as an auto level match, take the averages of signals A and B
> and then divide average B by average A. Multiply the actual A
> signal by the product of that division. This will make A match the
> average level of B.
>
> A more interesting way to do this would be to average the two
> averages to find the mean level between the signals, and then bring
> BOTH inputs to that level via the division method, rather than one
> to the other.
>
> p.s. throw an abs~ pre the input of average~ to make your stuff
> work in positive values.
>
>

Feb 03 2009 | 10:18 am

I don’t really know what the average~ rms value should be for saw~ but
there’s something that you need to consider, saw~ is an anti aliased
oscillator. And not a full saw waveform.

ej

On 3 févr. 09, at 10:43, Federico Vanni wrote:

>
> hi jack,
>
>
> the problem is that average~ gives a right rms value
> for the sine wave (0.707) and wrong rms values for other
> waveshapes (for example 0.46 circa for saw~ and so on)…
> So it would be difficult to take averages of two different
> signals.
> So how to take a right average to make the operation
> you wrote?
>
> thanks
> fv
>
>
>
>
>
>
>
>
> Il giorno 02/feb/09, alle ore 18:52, Jack ha scritto:
>
>>
>> Regarding rms, I can’t find a reference that gives values for sin/
>> saw waves, so I’m not sure if max is doing it wrong/differently
>> than you’d expect.
>>
>> As far as an auto level match, take the averages of signals A and B
>> and then divide average B by average A. Multiply the actual A
>> signal by the product of that division. This will make A match the
>> average level of B.
>>
>> A more interesting way to do this would be to average the two
>> averages to find the mean level between the signals, and then bring
>> BOTH inputs to that level via the division method, rather than one
>> to the other.
>>
>> p.s. throw an abs~ pre the input of average~ to make your stuff
>> work in positive values.
>>
>>
>

Feb 03 2009 | 8:23 pm

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