Yes, Peak: the +/- amplitude limits for the filter, typically,...
+12dB to -12dB. Frequencies "skirting" the center frequency being
selected will be un-affected within the limits of the frequency 
band limits and filter capabilities (some are better than others)
which is fixed, or controlled by the Q-Factor (if the filter has 
a Q control).

Q: center frequency divided by the bandwidth. As the bandwidth gets 
smaller, the amplitude at the center frequency gets greater. If you 
take the Q high enough, the filter will self-oscillate and become a 
very noisy oscillator (at least with a hardware filter, a Csound 
filter in the virtual realm ??? [have to try that sometime]).

"low shelving means it boost or cuts everything below the corner 
frequency and leaves everything above it alone"--- yes. 
How flat it is, is a matter of how good the filter is and how 
little the ripples and artifacts are.


-Partev


===================================================



--- dennis.raddle@gmail.com wrote:

From: Dennis Raddle 
To: csound@lists.bath.ac.uk
Subject: [Csnd] using parametric EQ
Date: Mon, 26 Dec 2011 14:55:58 -0800

Can someone explain the parametric EQ opcode to me (pareq).
Does "peaking" mode mean that it boosts (or cuts) frequencies around
a center frequency and leaves the rest of the spectrum intact?
What does "low shelving" and "high shelving" mean?
I'm guessing that low shelving means it boost or cuts everything
below the corner frequency and leaves everything above it alone. And
the shape of the boost or cut is flat. So the response would look
like a stairstep. Is this right?
What does Q mean in the shelving mode?
Thanks,
Dennis




_____________________________________________________________
Netscape.  Just the Net You Need.


Send bugs reports to the Sourceforge bug tracker
            https://sourceforge.net/tracker/?group_id=81968&atid=564599
Discussions of bugs and features can be posted here
To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"