- added

git-svn-id: http://moon:8086/svn/matlab/trunk@128 801c6759-fa7c-4059-a304-17956f83a07c
2020-07-23 11:10:12 +00:00
parent 0631c89f10
commit 1f5b0b0570
8 changed files with 288 additions and 1 deletions
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+function [B,A] = boost2(fs, fc, bw, gain);
+%BOOST - Design a boost filter at given gain, center
+%        frequency fc, bandwidth bw, and sampling rate fs
+%        (default = 1).
+%
+%        Cookbook formulae for audio EQ biquad filter coefficients
+%        by Robert Bristow-Johnson  <rbj@audioimagination.com>
+
+Q = fs/bw;
+w0 = 2*pi*fc/fs;
+
+A=sqrt(gain);
+alpha = sin(w0)/(2*Q) 
+
+b0 =   1 + alpha*A
+b1 =  -2*cos(w0)
+b2 =   1 - alpha*A
+a0 =   1 + alpha/A
+a1 =  -2*cos(w0)
+a2 =   1 - alpha/A
+
+A = [a0 a1 a2] / a0;
+B = [b0 b1 b2] / a0;
+
+if nargout==0
+  freqz(B,A);
+  title('Boost Frequency Response')
+end
+