Cycling 74 » Topic: Realtime Noise Filter

Realtime Noise Filter

cronoklee — Mon, 21 Mar 2011 15:14:36 +0000

Anyone know of a realtime noise filter object for max? I just want to clean up a noisy input signal.

Thanks

Re: Realtime Noise Filter

pid — Mon, 21 Mar 2011 16:10:34 +0000

two warnings: 1 – there is no such thing as a ‘realtime’ noise filter. 2 – this is almost impossible to do WELL in max. unless you use a vst / au. just saying.

Re: Realtime Noise Filter

cronoklee — Mon, 21 Mar 2011 16:43:45 +0000

OK thanks – can you suggest an alternative? Is there a handy noise gate object I could use?

Re: Realtime Noise Filter

cronoklee — Mon, 21 Mar 2011 18:24:00 +0000

Ah the built in onx.comp~ object has a ngThreshold parameter which is a reasonable noise gate.

Re: Realtime Noise Filter

jameswherever — Tue, 22 Mar 2011 21:49:28 +0000

@pid Could you possibly expand on why it is impossible to do well? I was thinking about attempting to programme one and an early indication as to why it might be a bad idea would be useful!

Thanks

Re: Realtime Noise Filter

Roman Thilenius — Tue, 22 Mar 2011 23:03:53 +0000

because it is quite complex and so it would need quite many signal
connections to build it, which means that in maxmsp it will take too
much CPU.

if a noise gate is really an alternative, i dont know. but with omx or with
average, rampsmooth and slide you will be able to make a simple noise
gate within minutes.

Re: Realtime Noise Filter

leafcutter — Wed, 23 Mar 2011 00:23:46 +0000

This one from MSP Tutorial 26 is really good:

– Pasted Max Patch, click to expand. –

Re: Realtime Noise Filter

pid — Wed, 23 Mar 2011 10:06:54 +0000

thanks roman

Re: Realtime Noise Filter

mudang — Wed, 23 Mar 2011 10:20:01 +0000

One could improve the tutorial patch by taking a sample of the noise (aka noise profile) and use this as the threshold for the filter.

Another thing would be to implement a downward expander (instead of simply “muting” the bins) in the pfft.

This might be rather tricky to implement in max, but not impossible ;)

Re: Realtime Noise Filter

jameswherever — Wed, 23 Mar 2011 16:24:08 +0000

Thanks. That’s really handy. Sorry to have not spotted the tutorial (do I hear distant cries or RTFM?!)

@Leafcutter – would that be John?

(sorry, just realised I can click on your name and go my answer!)