- Oct 15, 2011
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As we all know, Noise in the signal is inevitable, but undesirable. Usually we are able to avoid it (up to some point) using better quality gear and its setup, but sometimes that's not enough, so we are pushed to denoise the signal. DIs of Amplified and heavily compressed instruments are especially sensitive, because (as we all know) Compressors/Amplifiers/Distortion amplifies also the noise, especially were the signal is low or not present. There are more ways to do it:
1.Frequency filtering - using HPF, LPF and notching is quite common, but we can use it only to suppress noise of different frequencies than the signal. so for heavy/medium noise suppression this is not the (entire) solution.
2.Noise gate When instrument is playing, the noise falls to the background, so mostly noise is problem only when there should be silence. Noise gate handles these situations well, but sometimes it has problems with two things:
-It suppresses noise only when there should be silence - noise in the instrument lasts.
-On closing it's hard to set the right point between the instrument decay and the noise. Especially for Amplified guitars on palm mutes.
3. CPU intensive noise reduction algorithms solution to problems of frequency filtering and noise gating is their combination - multi-band noise-gate. It is known under many names and plugin forms like Waves X-noise and Z-noise, Noise reduction from Christian Budde to name just some of them. In fact most DAWs have them in their native effects racks.
What it does is, that it splits the signal into many (512,1024 or 2048 usually) frequency bands (using FFT - fast fourier transform) and noise gate them separately. This handles of 99.9% of noise anywhere in the signal introducing almost no artifacts. In fact it can possibly notch the noise in between the harmonics of the sound (if it's tuned instrument).
Where's the bug? - FFT is extremely CPU intensive, which means you are limited to only few instances per project, or to use it as process only (destructively). FFT also uses big input and output buffers => introduces great latency and it's not suitable for live performance. In fact most Noise reduction algorithms are process only and doesn't support live playback (due to above mentioned reasons)
In praxis we don't actually need such perfect noise reduction sacrificing our precious CPU. Look at the spectrograph of most instruments. You can see that higher frequencies are present only at the transients - when you hit the drum/pluck the string. They decay in about 30ms and afterwards only noise is present at these frequencies - the frequencies we are most sensitive to.
Solution is the multiband noise gate! Not with 2048 bands using FTT! - just simple 3-band or 4-band noise gate, to led us gate different frequency regions independently.
It almost totally reduced noise in my electric guitar DI (I use ampsims) with zero latency and minimal CPU use... Whanna try it??? And here comes the bad news - There are very few plugins capable of multiband noise gating/downward expanding and not a single one specialized to this task (as far as I know). To mention two: Izotope Ozone, IQ4gui, Reafir (not sure about this one, seems it also uses FFT)...
I was forced to make Multiband Noise gate myself in synthmaker. Works great! Only problem is I have a FL studio version of SM, so it exports only to FruityLoops plugins - not VST.
I what to ask if someone is interested in such plugin???
I might make an VST of it somehow.
Is there somenone whom can I send the FL project, who has both FL and synthmaker, to export it to VST for me? (I'll try also the SM forum if anyone will be interested in such plugin)
I can post Clips If you what....
1.Frequency filtering - using HPF, LPF and notching is quite common, but we can use it only to suppress noise of different frequencies than the signal. so for heavy/medium noise suppression this is not the (entire) solution.
2.Noise gate When instrument is playing, the noise falls to the background, so mostly noise is problem only when there should be silence. Noise gate handles these situations well, but sometimes it has problems with two things:
-It suppresses noise only when there should be silence - noise in the instrument lasts.
-On closing it's hard to set the right point between the instrument decay and the noise. Especially for Amplified guitars on palm mutes.
3. CPU intensive noise reduction algorithms solution to problems of frequency filtering and noise gating is their combination - multi-band noise-gate. It is known under many names and plugin forms like Waves X-noise and Z-noise, Noise reduction from Christian Budde to name just some of them. In fact most DAWs have them in their native effects racks.
What it does is, that it splits the signal into many (512,1024 or 2048 usually) frequency bands (using FFT - fast fourier transform) and noise gate them separately. This handles of 99.9% of noise anywhere in the signal introducing almost no artifacts. In fact it can possibly notch the noise in between the harmonics of the sound (if it's tuned instrument).
Where's the bug? - FFT is extremely CPU intensive, which means you are limited to only few instances per project, or to use it as process only (destructively). FFT also uses big input and output buffers => introduces great latency and it's not suitable for live performance. In fact most Noise reduction algorithms are process only and doesn't support live playback (due to above mentioned reasons)
In praxis we don't actually need such perfect noise reduction sacrificing our precious CPU. Look at the spectrograph of most instruments. You can see that higher frequencies are present only at the transients - when you hit the drum/pluck the string. They decay in about 30ms and afterwards only noise is present at these frequencies - the frequencies we are most sensitive to.
Solution is the multiband noise gate! Not with 2048 bands using FTT! - just simple 3-band or 4-band noise gate, to led us gate different frequency regions independently.
It almost totally reduced noise in my electric guitar DI (I use ampsims) with zero latency and minimal CPU use... Whanna try it??? And here comes the bad news - There are very few plugins capable of multiband noise gating/downward expanding and not a single one specialized to this task (as far as I know). To mention two: Izotope Ozone, IQ4gui, Reafir (not sure about this one, seems it also uses FFT)...
I was forced to make Multiband Noise gate myself in synthmaker. Works great! Only problem is I have a FL studio version of SM, so it exports only to FruityLoops plugins - not VST.
I what to ask if someone is interested in such plugin???
I might make an VST of it somehow.
Is there somenone whom can I send the FL project, who has both FL and synthmaker, to export it to VST for me? (I'll try also the SM forum if anyone will be interested in such plugin)
I can post Clips If you what....
