diff options
| author | Damien Zammit <damien@zamaudio.com> | 2017-06-08 02:04:12 +1000 |
|---|---|---|
| committer | Damien Zammit <damien@zamaudio.com> | 2017-06-08 02:04:12 +1000 |
| commit | ca815acd6150669347e15114bd6276d5e133ac6c (patch) | |
| tree | 51ffbb512aada4424eecd2c1d3caf9f7ba574bd2 | |
| parent | c4a4857b8710654e8b91aa354f602331ed8fc859 (diff) | |
a-EQ: DSP bugfix
Previously there were large spurious spikes in the signal when
the bandwidth parameter was adjusted on a pure sine tone
for the peaking circuits. This has been *greatly* reduced if not
eliminated by fixing a typo in two of the equations.
| -rw-r--r-- | libs/plugins/a-eq.lv2/a-eq.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/libs/plugins/a-eq.lv2/a-eq.c b/libs/plugins/a-eq.lv2/a-eq.c index 7a15c8a14f..99138fc21c 100644 --- a/libs/plugins/a-eq.lv2/a-eq.c +++ b/libs/plugins/a-eq.lv2/a-eq.c @@ -270,12 +270,12 @@ activate(LV2_Handle instance) static void linear_svf_set_peq(struct linear_svf *self, float gdb, float sample_rate, float cutoff, float bandwidth) { double f0 = (double)cutoff; - double q = (double)pow(2.0, 1.0 / bandwidth) / (pow(2.0, bandwidth) - 1.0); + double q = (double)pow(2.0, 0.5 * bandwidth) / (pow(2.0, bandwidth) - 1.0); double sr = (double)sample_rate; double A = pow(10.0, gdb/40.0); self->g = tan(M_PI * (f0 / sr)); - self->k = 1.0 / (q * A); + self->k = 1.0 / q; self->a[0] = 1.0 / (1.0 + self->g * (self->g + self->k)); self->a[1] = self->g * self->a[0]; |