24 Aug
2013
24 Aug
'13
3:16 p.m.
CAPS Audio Plugin Suite 0.9.12
http://quitte.de/dsp/caps.html
New in this release:
Eq4p, a four-way parametric equaliser
http://quitte.de/dsp/caps.html#Eq4p
(Unlike Fons', this one uses parallel processing but lacks control
smoothening other than that provided by a continuous IIR filter
history.)
Elsewhere, a few stupid bugs have been fixed (one of them keeping
PhaserII from reaching strong effect levels), the documentation has
undergone a major revision, many plugins have been polished, some
renamed, and lots of unnecessary ones have been removed.
http://quitte.de/dsp/caps.html#Download
Enjoy!
24 Aug
24 Aug
4:44 p.m.
New subject: [LAD] [ANN] CAPS 0.9.12
On Sat, Aug 24, 2013 at 03:14:14PM +0200, Tim Goetze wrote:
New in this release:
Eq4p, a four-way parametric equaliser
http://quitte.de/dsp/caps.html#Eq4p
* Insert in Ardour's master strip.
* Make sure your speakers are disconnected.
* Provide some input signal at around -20 dB.
* Set first section to bandpass, Q = 0.8, gain = +15 dB.
* Use the mouse wheel on the frequency slider.
* Observe output levels well above +40 dB.
The F slider switching between its extremes when using the
mouse wheel is of course a bug in A3. But it still provides
valid input to the plugin (which could come from automation
or MIDI as well).
Apart from this, it also produces multiplicative LF noise
at some low frequency settings. This is typical for type of
filter used.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
9:59 p.m.
New subject: [LAD] [ANN] CAPS 0.9.12
[Fons Adriaensen]
On Sat, Aug 24, 2013 at 03:14:14PM +0200, Tim Goetze
wrote:
> Eq4p, a four-way parametric equaliser
> http://quitte.de/dsp/caps.html#Eq4p
[...]
The F slider switching between its extremes when using
the
mouse wheel is of course a bug in A3. But it still provides
valid input to the plugin (which could come from automation
or MIDI as well).
Thanks a lot for the evaluation and the problem report; I hope this
hasn't caused damage to your ears (which I value highly!) or
equipment. It adds to the evidence that implementing thorough control
smoothening is inevitable in the long run.
Apart from this, it also produces multiplicative LF
noise
at some low frequency settings. This is typical for type of
filter used.
I haven't been able to measure such noise at anywhere near audible
levels, not even when followed by high-gain saturation. If you have,
can you point out an input signal and settings that can provoke it?
Thank you,
Tim
11:48 p.m.
New subject: [LAD] [ANN] CAPS 0.9.12
On Sat, Aug 24, 2013 at 09:56:47PM +0200, Tim Goetze wrote:
The noise remains below audible levels in this case (there
are some plugins that are much worse). But it is still much
higher than it should be. The reason is that a biquad is not
the right filter for this job, at least not at low frequencies.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
Thanks a lot for the evaluation and the problem
report; I hope this
hasn't caused damage to your ears (which I value highly!) or
equipment.
I've learned to mute monitoring while doing such tests...
It adds to the evidence that implementing thorough
control
smoothening is inevitable in the long run.
That may or not solve the problem. You have 3 input parameters
(P), and 5 biquad coefficients (C). Interpolating the C can
make a biquad unstable, and if this happens it doesn't matter
how fast or slow you do it. The only solution is to interpolate
the C only between sets of values that correspond to values of
the P that are not too far apart. So you need two levels, first
on the P to limit the rate of change of the parameters, then on
the C to avoid zipper noise.
Apart from
this, it also produces multiplicative LF noise
at some low frequency settings. This is typical for type of
filter used.
I haven't been able to measure such noise at anywhere near audible
levels, not even when followed by high-gain saturation. If you have,
can you point out an input signal and settings that can provoke it?
25 Aug
25 Aug
12:24 a.m.
New subject: [LAD] [ANN] CAPS 0.9.12
[Fons Adriaensen]
I'm planning to evade this problem by crossfading between two parallel
static filters. Some phase mismatch issues can probably be expected
when the parameter sweep covers a larger range, but I'm hopeful it
will turn out not to be much of a problem in actual practice, and that
we will find out soon. It really needs a fix.
Tim
I've learned to mute monitoring while doing such
tests...
I was suspecting you had :)
It adds to the
evidence that implementing thorough control
smoothening is inevitable in the long run.
That may or not solve the problem. You have 3 input parameters
(P), and 5 biquad coefficients (C). Interpolating the C can
make a biquad unstable, and if this happens it doesn't matter
how fast or slow you do it. The only solution is to interpolate
the C only between sets of values that correspond to values of
the P that are not too far apart. So you need two levels, first
on the P to limit the rate of change of the parameters, then on
the C to avoid zipper noise.
1:05 a.m.
New subject: [LAD] [ANN] CAPS 0.9.12
On Sun, Aug 25, 2013 at 12:21:52AM +0200, Tim Goetze wrote:
I'm planning to evade this problem by crossfading
between two parallel
static filters. Some phase mismatch issues can probably be expected
when the parameter sweep covers a larger range, but I'm hopeful it
will turn out not to be much of a problem in actual practice, and that
we will find out soon. It really needs a fix.
I doubt very much if that will provide a practiacal solution.
The state of the filter depends on signal history. Depending
on the parameters, this could be quite long. So you would
either have to
* run the new filter (with the new parameters) for some
time before crossfading, which will complicate the
code, or
* copy the state of the old into the new filter, but
with a biquad this can again produce quite heavy
spikes wich may last much longer than your crossfade.
This can happen even when both the new and old filter
are set to 0 dB gain.
The simple solution is to smooth the input parameters,
limiting their rate of change. Nobody expects an EQ
section to change from 100 Hz to 10 kHz in less than
half a second (unless it's a synth VCF module, but then
you definitely need something else than a biquad).
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
2:02 a.m.
New subject: [LAD] [ANN] CAPS 0.9.12
[Fons Adriaensen]
On Sun, Aug 25, 2013 at 12:21:52AM +0200, Tim Goetze
wrote:
I think the question deciding the quality of the filter fade is, how
big will the phase difference between the two filters be? Amplitude
differences shouldn't matter when we crossfade, as long as we're not
phase-canceling.
These are very simple filters that don't take long to settle on a
stable phase relationship. A reasonably small parameter change will
not change their phase response by much, so my expectation is that
there will be only little cancellation and the fade thus close to
imperceptible; at most a slight attenuation of high-frequency content.
Just theorising over a glass of wine though.
I'm planning to evade this problem by
crossfading between two parallel
static filters. Some phase mismatch issues can probably be expected
when the parameter sweep covers a larger range, but I'm hopeful it
will turn out not to be much of a problem in actual practice, and that
we will find out soon. It really needs a fix.
I doubt very much if that will provide a practiacal solution.
The state of the filter depends on signal history. Depending
on the parameters, this could be quite long. The simple solution is to smooth the input parameters,
limiting their rate of change. Nobody expects an EQ
section to change from 100 Hz to 10 kHz in less than
half a second (unless it's a synth VCF module, but then
you definitely need something else than a biquad).
Yes, that is a very convenient way to solve it, perhaps the preferable
one given the realities.
Tim
4:17 p.m.
New subject: [ANN] CAPS 0.9.13, Re: [LAD] [ANN] CAPS 0.9.12
The new version of CAPS comes -- among other, minor changes -- with
control input smoothening for Eq4p, establishing gentle manners in the
face of even the most drastic parameter changes:
http://quitte.de/dsp/caps.html#Download
Due to an unrelated change, the plugin will even run slightly quicker
with static parameters.
The filter cross-fade has the nice additional property of softening
the transition between different filter types somewhat.
Still pondering generic lowpass control smoothening, but it appears to
be best applied centrally so all plugins can benefit.
Enjoy!
6:47 p.m.
New subject: [ANN] CAPS 0.9.13, Re: [LAD] [ANN] CAPS 0.9.12
On Sun, Aug 25, 2013 at 04:15:35PM +0200, Tim Goetze wrote:
Still pondering generic lowpass control smoothening,
but it appears to
be best applied centrally so all plugins can benefit.
I'd disagree about that. In general a host has not idea of
what is required to do this correctly. Same for interpolating
e.g. automation data.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
7:03 p.m.
New subject: [ANN] CAPS 0.9.13, Re: [LAD] [ANN] CAPS 0.9.12
[Fons Adriaensen]
On Sun, Aug 25, 2013 at 04:15:35PM +0200, Tim Goetze
wrote:
Ah, sorry, I was being vague. "Applied centrally" within CAPS, not
host-side.
Thanks again for the helpful discussion,
Tim
Still pondering generic lowpass control
smoothening, but it appears to
be best applied centrally so all plugins can benefit.
I'd disagree about that. In general a host has not idea of
what is required to do this correctly. Same for interpolating
e.g. automation data. 
6:52 p.m.
New subject: [LAD] [ANN] CAPS 0.9.12
Hi, thanks for the software!
I'm using Lorenz as a modulation source, but it appears that amplitude
decreases greatly as I slow down the rate. Is there a high pass / DC
blocking filter somewhere in there?
Here's my code, in Supercollider:
{SinOsc.ar(freq: 100 * (2 ** LADSPA.ar(1,1774,0.01,1,1,0,100)))}.play
thanks again,
Mark Hadman
On 25 August 2013 01:00, Tim Goetze <tim(a)quitte.de> wrote:
[Fons Adriaensen]
On Sun, Aug 25, 2013 at 12:21:52AM +0200, Tim
Goetze wrote:
I think the question deciding the quality of the filter fade is, how
big will the phase difference between the two filters be? Amplitude
differences shouldn't matter when we crossfade, as long as we're not
phase-canceling.
These are very simple filters that don't take long to settle on a
stable phase relationship. A reasonably small parameter change will
not change their phase response by much, so my expectation is that
there will be only little cancellation and the fade thus close to
imperceptible; at most a slight attenuation of high-frequency content.
Just theorising over a glass of wine though.
I'm planning to evade this problem by
crossfading between two parallel
static filters. Some phase mismatch issues can probably be expected
when the parameter sweep covers a larger range, but I'm hopeful it
will turn out not to be much of a problem in actual practice, and that
we will find out soon. It really needs a fix.
I doubt very much if that will provide a practiacal solution.
The state of the filter depends on signal history. Depending
on the parameters, this could be quite long. The simple solution is to smooth the input
parameters,
limiting their rate of change. Nobody expects an EQ
section to change from 100 Hz to 10 kHz in less than
half a second (unless it's a synth VCF module, but then
you definitely need something else than a biquad).
Yes, that is a very convenient way to solve it, perhaps the preferable
one given the realities.
Tim
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7:36 p.m.
New subject: [LAD] [ANN] CAPS 0.9.12
[mark hadman]
I'm using Lorenz as a modulation source, but it
appears that amplitude
decreases greatly as I slow down the rate. Is there a high pass / DC
blocking filter somewhere in there?
Yes, there is.
This effect of the hp filter will be greatly reduced when I get to
implement the same fix that the Roessler fractal has already seen,
subtraction of a DC constant on each of the three axes.
Thank you for the reminder,
Tim
26 Aug
26 Aug
6:20 p.m.
New subject: 0.9.15, Re: [LAD] [ANN] CAPS 0.9.12
[Tim Goetze]
[mark hadman]
Done, and the highpass can now be tuned or turned off entirely.
http://quitte.de/dsp/caps.html#Fractal
http://quitte.de/dsp/caps.html#Download
Tim
I'm using Lorenz as a modulation source, but
it appears that amplitude
decreases greatly as I slow down the rate. Is there a high pass / DC
blocking filter somewhere in there?
Yes, there is.
This effect of the hp filter will be greatly reduced when I get to
implement the same fix that the Roessler fractal has already seen,
subtraction of a DC constant on each of the three axes. 
11:07 p.m.
New subject: 0.9.15, Re: [LAD] [ANN] CAPS 0.9.12
Hello Tim!
Thanks again for your fixes. Although I've never used the fractal plugins, I
downloaded it. It's always good to be up to date. So many very helpful and
just usable plugins in that suite! Tghanks for your continued work and
improvements!
Warm regards
Julien
----------------------------------------
http://juliencoder.de/nama/music.html
27 Aug
27 Aug
1:46 p.m.
New subject: 0.9.15, Re: [LAD] [ANN] CAPS 0.9.12
Ave Iulius,
Thanks! I'm very happy to know that with your keen ears you find many
of these plugins useful. I have more ideas for new features and
plugins but currently polishing things is my prime objective.
Tim
[Julien Claassen]
Thanks again for your fixes. Although I've never
used the fractal plugins, I
downloaded it. It's always good to be up to date. So many very helpful and just
usable plugins in that suite! Tghanks for your continued work and improvements!
4165
days inactive
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days old
linux-audio-user@lists.linuxaudio.org
14 comments
4 participants
participants (4)
-
Fons Adriaensen -
Julien Claassen -
mark hadman -
Tim Goetze