Multiband Limiter
Posted: Thu Jan 03, 2013 8:55 am
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Example file <- old
Sunsynth Module (updated) | HQ mono
LQ Sunsynth Module (updated) | LQ mono
Demonstration of the updated multiband limiter for the final version of SunVox 1.73 (CAUTION! loud!):
Note, how the side-chaining-effect of the source signal vanishes, when all bands are boosted separately.
Background
If you're like me and belong to those, who recorded music to their 486 PCs back in the early 90s, then you probably have faced how waveforms turned from this...
(Enigma, Sadeness, 1990)
...into this...
(Paul Brown, Moment by Moment, 2004)
...without sounding like 3:20 of a continous hardcore bassdrum. Both tracks belong to rather calm sounding genres (New Age, Smooth Jazz, Chillout).
And us poor tracker musicians would just not know what was going on there. Only that the 'loud' tracks sounded more 'upfront' while the other ones (including ours) sounded too quiet.
Normalizing wouldn't help. If anyone of us knew a Compressor and would use it back then, soon his track would be puming like Daft Punk's Revolution 909.
Today we know it's some sort of mastering. There are plugIns like 'Maximizers', 'Boosters' and whatnot that do some large part of the work for you to get similar results.
The Multiband Limiter in this article is one of those tools that shall help you to not run into clipping/pumping while you're bringing background details up to the front.
What is it good for?
Like Compressors and Limiters it allows you to artificially raise your dynamic range. But (hopefully) in a more sophisticated way.
It allows you to push the loudnes (not volume) higher without getting the pumping artifact of an overdriven compressor.
It's useful for vocal processing. E.g. if you want to preserve bass but want to avoid loud pops. Of if you want to have bright highs but no sharp Ess-es (De-essing).
It helps you join the Loudness War. DO NOT DO THIS.
The example file
As usual the example file shows the multiband limiter in action. You'll notice, this time I used Menthes' Narrower/Bandpass-Filter, which saved me some space on the screen. In my module I have its Exponential Frequencies turned off (and I also fixed a little mistake as the LP Freq-Roll-off wasn't assigned correctly).
If you play the pattern, you'll hear a loop, which is an excerpt of Level 42's 'Lessons In Love' being processed by the DSP chain. The original recording from the 80's offers a large dynamic range. Peaks are really peaks. This helps us demonstrate how a usual compressor would start pumping on each of these peaks while the multiband limiter gains the same loudness without the pumping. To hear the difference, unmute the 'COMPARE' DSP. It'll automatically mute the multiband limiter's output and have it bypassed. Hopefully you also notice that the strong boosting turns the sound muddy. Of course this example is exaggerating the loudness boost to clearly show the wet/dry difference. Don't take this as an example on how far you should go. Never.
What is happening?
The source signal is being divided into five separated frequency bands. Subs ( - 70Hz), Low Mids (70 - 300 Hz), Mids (300 Hz - 2 KHz), High Mids (2 - 8 KHz) and the Highs (8 Khz and above).
Each of these bands' outputs is being compressed by a dedicated compressor with aggressive settings (0 Attack time, 1 ms Release time, 100% Slope). Of course such fast release times would lead to audible distortion in the bass and mid range, but:
Behind each compressor there are again post filters with the same settings as on the inputs. This makes sure that any accidental harmonics get cut out, which gives us a very high quality, even if we push it very hard (compare it to other multiband compressors).
Now, opposed to a usual compressor, which would compress the complete signal, this processor lowers only the bass, when the bass gets too loud. Exactly the same happends in all the other bands, too. So the peak of a bassdrum won't make the compressor attenuate the high hats and a loud crash cymbal won't do the same with a bassdrum. Each peak affects only the frequency range, where it occours. This way you get a higher loudness with much less pumping artifacts. The demo video also shows, how the side-chaining (the wanted pumping in the source signal) can vanish, if we boost the separate frequencies to extreme levels, as the bassdrum no longer remains the peak.
The SunSynth modules
The SunSynth metamodules work like any of the native effects in your signal chain. Just use the "Load" feature in Sunvox to locate the downloaded metamodule from your disk and connect the output of anything you like to it.
The new versions take advantage of the improved and very reliable compressor. Also the internal compressors of all multiband limiters have been exchanged by the lookahead compressor, so each band's peak will be handled faster now. Actually, this is a Lookahead Multiband Limiter now :)
The LQ-Versions are meant for devices with slow CPUs. I have set their filters (thx to NightRadio's instructions) and volume to differ as little as possible from the HQ-versions. But you will have to expect some slightly audible differences.
The mono versions can be useful, where the stereo versions would be CPU-wise a waste for processing monoaural sources (e.g. lead vocals).
I hope you'll have some fun with this.
gilzad
edit: updated the HQ- and LQ-version, added mono-versions and made corrections, much higher quality now. Also reduced a bunch of redundant amplifiers.
Example file <- old
Sunsynth Module (updated) | HQ mono
LQ Sunsynth Module (updated) | LQ mono
Demonstration of the updated multiband limiter for the final version of SunVox 1.73 (CAUTION! loud!):
Note, how the side-chaining-effect of the source signal vanishes, when all bands are boosted separately.
Background
If you're like me and belong to those, who recorded music to their 486 PCs back in the early 90s, then you probably have faced how waveforms turned from this...
(Enigma, Sadeness, 1990)
...into this...
(Paul Brown, Moment by Moment, 2004)
...without sounding like 3:20 of a continous hardcore bassdrum. Both tracks belong to rather calm sounding genres (New Age, Smooth Jazz, Chillout).
And us poor tracker musicians would just not know what was going on there. Only that the 'loud' tracks sounded more 'upfront' while the other ones (including ours) sounded too quiet.
Normalizing wouldn't help. If anyone of us knew a Compressor and would use it back then, soon his track would be puming like Daft Punk's Revolution 909.
Today we know it's some sort of mastering. There are plugIns like 'Maximizers', 'Boosters' and whatnot that do some large part of the work for you to get similar results.
The Multiband Limiter in this article is one of those tools that shall help you to not run into clipping/pumping while you're bringing background details up to the front.
What is it good for?
Like Compressors and Limiters it allows you to artificially raise your dynamic range. But (hopefully) in a more sophisticated way.
It allows you to push the loudnes (not volume) higher without getting the pumping artifact of an overdriven compressor.
It's useful for vocal processing. E.g. if you want to preserve bass but want to avoid loud pops. Of if you want to have bright highs but no sharp Ess-es (De-essing).
It helps you join the Loudness War. DO NOT DO THIS.
The example file
As usual the example file shows the multiband limiter in action. You'll notice, this time I used Menthes' Narrower/Bandpass-Filter, which saved me some space on the screen. In my module I have its Exponential Frequencies turned off (and I also fixed a little mistake as the LP Freq-Roll-off wasn't assigned correctly).
If you play the pattern, you'll hear a loop, which is an excerpt of Level 42's 'Lessons In Love' being processed by the DSP chain. The original recording from the 80's offers a large dynamic range. Peaks are really peaks. This helps us demonstrate how a usual compressor would start pumping on each of these peaks while the multiband limiter gains the same loudness without the pumping. To hear the difference, unmute the 'COMPARE' DSP. It'll automatically mute the multiband limiter's output and have it bypassed. Hopefully you also notice that the strong boosting turns the sound muddy. Of course this example is exaggerating the loudness boost to clearly show the wet/dry difference. Don't take this as an example on how far you should go. Never.
What is happening?
The source signal is being divided into five separated frequency bands. Subs ( - 70Hz), Low Mids (70 - 300 Hz), Mids (300 Hz - 2 KHz), High Mids (2 - 8 KHz) and the Highs (8 Khz and above).
Each of these bands' outputs is being compressed by a dedicated compressor with aggressive settings (0 Attack time, 1 ms Release time, 100% Slope). Of course such fast release times would lead to audible distortion in the bass and mid range, but:
Behind each compressor there are again post filters with the same settings as on the inputs. This makes sure that any accidental harmonics get cut out, which gives us a very high quality, even if we push it very hard (compare it to other multiband compressors).
Now, opposed to a usual compressor, which would compress the complete signal, this processor lowers only the bass, when the bass gets too loud. Exactly the same happends in all the other bands, too. So the peak of a bassdrum won't make the compressor attenuate the high hats and a loud crash cymbal won't do the same with a bassdrum. Each peak affects only the frequency range, where it occours. This way you get a higher loudness with much less pumping artifacts. The demo video also shows, how the side-chaining (the wanted pumping in the source signal) can vanish, if we boost the separate frequencies to extreme levels, as the bassdrum no longer remains the peak.
The SunSynth modules
The SunSynth metamodules work like any of the native effects in your signal chain. Just use the "Load" feature in Sunvox to locate the downloaded metamodule from your disk and connect the output of anything you like to it.
The new versions take advantage of the improved and very reliable compressor. Also the internal compressors of all multiband limiters have been exchanged by the lookahead compressor, so each band's peak will be handled faster now. Actually, this is a Lookahead Multiband Limiter now :)
The LQ-Versions are meant for devices with slow CPUs. I have set their filters (thx to NightRadio's instructions) and volume to differ as little as possible from the HQ-versions. But you will have to expect some slightly audible differences.
The mono versions can be useful, where the stereo versions would be CPU-wise a waste for processing monoaural sources (e.g. lead vocals).
I hope you'll have some fun with this.
gilzad
edit: updated the HQ- and LQ-version, added mono-versions and made corrections, much higher quality now. Also reduced a bunch of redundant amplifiers.