6 Oct
2006
6 Oct
'06
12:25 a.m.
John Rigg wrote:
On Thu, Oct 05, 2006 at 09:01:19AM -0500, Andres
Cabrera wrote:
Yes, I meant low pass filter.... Maybe the window size or something
similar has to do with the apparent high pass filtering?
Andrés
I was assuming that RMS measruments and windowed
integration act as a
high pass filter, is this not true?
No, a low pass filter integrates and a high pass filter differentiates.
The audio signal is rectified before it can be
filtered and used for
gain control, so there is no AC signal for the filter to act on,
just a varying DC level. The time constants for the filter
(eg. charge and discharge rates on a capacitor in an analog LP filter)
determine the rate at which the control signal can increase or
decrease, and hence the attack and decay times.
John