diff --git a/src/sfizz/dsp/filters/filters_modulable.dsp b/src/sfizz/dsp/filters/filters_modulable.dsp
index fa46f7e0..2d4b9907 100644
--- a/src/sfizz/dsp/filters/filters_modulable.dsp
+++ b/src/sfizz/dsp/filters/filters_modulable.dsp
@@ -11,6 +11,7 @@ rbj = library("rbj_filters.dsp");
 //     b0,b1,b2,a1,a2 : normalized coefficients
 //-------------------------------------------------------------------------
 biquad(b0,b1,b2,a1,a2) = fi.iir((b0,b1,b2),(a1,a2));
+biquadTf2(b0,b1,b2,a1,a2) = fi.tf22t(b0,b1,b2,a1,a2);
 
 //-------------------------------------------------------------------------
 // Biquad filter using smoothed coefficients
@@ -18,6 +19,7 @@ biquad(b0,b1,b2,a1,a2) = fi.iir((b0,b1,b2),(a1,a2));
 //     b0,b1,b2,a1,a2 : normalized coefficients
 //-------------------------------------------------------------------------
 smoothBiquad(s,b0,b1,b2,a1,a2) = biquad(b0:s,b1:s,b2:s,a1:s,a2:s);
+smoothBiquadTf2(s,b0,b1,b2,a1,a2) = biquadTf2(b0:s,b1:s,b2:s,a1:s,a2:s);
 
 //-------------------------------------------------------------------------
 // RBJ filter of a specific type using smoothed coefficients
@@ -27,14 +29,14 @@ smoothBiquad(s,b0,b1,b2,a1,a2) = biquad(b0:s,b1:s,b2:s,a1:s,a2:s);
 //     q : height of the resonant peak in linear units
 //-------------------------------------------------------------------------
 rbjLpfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).LPF,x) : smoothBiquad(s);
-rbjHpfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).HPF,x) : smoothBiquad(s);
-rbjBpfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).BPF,x) : smoothBiquad(s);
-rbjNotchSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).notch,x) : smoothBiquad(s);
-rbjApfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).APF,x) : smoothBiquad(s);
-rbjPeakingEqSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).peakingEQ,x) : smoothBiquad(s);
-rbjPeakingNotchSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).peakNotch,x) : smoothBiquad(s);
-rbjLowShelfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).lowShelf,x) : smoothBiquad(s);
-rbjHighShelfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).highShelf,x) : smoothBiquad(s);
+rbjHpfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).HPF,x) : smoothBiquadTf2(s);
+rbjBpfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).BPF,x) : smoothBiquadTf2(s);
+rbjNotchSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).notch,x) : smoothBiquadTf2(s);
+rbjApfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).APF,x) : smoothBiquadTf2(s);
+rbjPeakingEqSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).peakingEQ,x) : smoothBiquadTf2(s);
+rbjPeakingNotchSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).peakNotch,x) : smoothBiquadTf2(s);
+rbjLowShelfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).lowShelf,x) : smoothBiquadTf2(s);
+rbjHighShelfSmooth(s,f,g,q,x) = (rbj.filtercoeff(f,g,q).highShelf,x) : smoothBiquadTf2(s);
 
 //-------------------------------------------------------------------------
 // 1-pole low-pass filter