On 11/03/11 06:17, Q wrote:
Hello
I'm looking for a resonant filter that's switchable between lowpass,
bandpass and highpass and which has a traditional ADSR envelope
controlling it. I'm wanting something that can be used in JACK Rack or
something like that, or which could be used as a plugin in Ardour, in
order to process incoming audio in real time.
There are plenty of LADSPA filter plugins, but they all seem to be
either static or swept by an LFO or similar. I thought someone, at some
point, might have made a filter and envelope triggered by an incoming
signal, in the way that a synth's filter does.
It looks like all the building blocks are probably there in various
LADSPA plugins, but I can't figure out how you'd connect them together.
AlsaModularSynth could probably do exactly that. However, I'd also look
at PHASEX -- it's a synth, but like many hardware synths it has the
ability to turn off its oscillators and process an external signal (from
a JACK port) through its filters, using its envelopes and LFOs for
modulation.
I'd also consider a hardware solution (but only a
cheap one, as finances
are very tight at the moment) and in some ways it would have some
advantages. I thought there was bound to be a guitar stompbox that would
do that (and no doubt a cheap Behringer knock-off version as well!), but
so far I've not turned up anything suitable.
Nothing cheap that I know of, but Moog's MF-101 does fit the bill, if
only for a low-pass filter:
http://www.moogmusic.com/moogerfooger/?section=product&product_id=5
Thanks
Leigh