Stereo Tool

BETA006:

Windows 32 bit:
Windows stand alone: http://www.stereotool.com/download/ster ... 51-006.exe
Winamp DSP: http://www.stereotool.com/download/dsp_ ... 51-006.exe

CHANGES:
- Trying a different multiband limiter in the Advanced Clipper. This time without phase optimizer. I'm very curious which version you guys prefer!

When I added an output to hear what the limiter was doing, I discovered that the 'raw' limiter output sounded quite horrible (other filtering cleaned it up afterwards, but that's not really a good idea). I have redesigned it completely now, and the raw output now sounds ok. But the behavior is also a bit different. On top of these changes, I have added protection against punching holes by high frequencies, and I have tried to protect mid-tones a bit more against too loud tones.

Note: Release speed is currently optimized for 128-256 bands. 2048 bands is broken, as is the limiter when using the composite clipper.


OLDER:
- Added multiband pre-limiter/phase optimizer to the Advanced Clipper.

Using lower limiting levels lowers the loudest sounds in the mix. Since bass is often the loudest sound it tends to reduce bass more than other sounds.

BETA007:

Windows 32 bit:
Windows stand alone: http://www.stereotool.com/download/ster ... 51-007.exe
Winamp DSP: http://www.stereotool.com/download/dsp_ ... 51-007.exe

CHANGES:
- Changed some things back to how they were in version 005 - Bojcha reported (and I confirmed) some weird artifacts in version 006. If you enable METHOD2 you get the 006 behavior, that's for my own tests and I will remove METHOD2 later.
- Added Smother filter. The higher you set it, the more it will ONLY affect the loudest sounds. If you have multiple loud tones (for example a bass and a loud voice), setting this very high might cause only one of the two to be effected - setting it very low will affect everything though.

The limiter is still broken when using the composite clipper.


OLDER:
- Added multiband pre-limiter/phase optimizer to the Advanced Clipper.
- Trying a different multiband limiter in the Advanced Clipper. This time without phase optimizer. I'm very curious which version you guys prefer!

Using lower limiting levels lowers the loudest sounds in the mix. Since bass is often the loudest sound it tends to reduce bass more than other sounds.

Hi Hans. I 've been testing the pre-limiter but the end result is not as good as i was expecting... It gives you more loundness but it produces distortion and makes the sound rough. I think if the problem of distortions is fixed it would be nice (especially for FM and not so much for web radio stations). That's all from me.

Thanks Hans

_________________
Very proud user of Stereo Tool since 2010. Thanks Hans.

My radio station
http://amradio.ddns.net

Mpex: can you send me your settings? The limiter is supposed to reduce distortion, if used at a low level.

I just realized something new, that might lead to a change in how the limiter works.

The purpose of the limiter is as follows: In some cases, certain sounds (often loud female voices or other constant sounds, or bass) are very loud compared to the other sounds. This can sound unpleasant, and if it goes into the clipper at a high level, the one loud tone will push other sounds down a lot even though the loud sound can in the end not be louder than a specific level (+2.1 dB, typically). These really loud tones also tend to sound - this is a bit hard to explain - 'woolly' in the clipper output.

So, the idea here is to lower the level of those really loud tones before entering the clipper, while not touching the other sounds.

I just realized a few things. Based on what I just wrote, normally the limiter should only act on a few really loud sounds, and not touch anything else. Moreover, if there is not clearly one very loud sound present, it should do nothing. Setting the Smother slider higher kinda takes care of that - but only kinda. It works well if a specific frequency sticks out - it will only touch the band that contains that frequency. But if all frequencies are equal in level (white noise), it will touch them all. Which is bad: It will have more effect on white noise than on a tone. While the whole idea was the opposite: It must lower a tone but leave white noise alone.

The good news is that this is relatively simple to fix: I can look which band has the biggest effect and then divide the amount of effect in that band over all the bands. Which means that in case of a single loud tone it will do the same thing it does now, but in case of white noise it will do almost nothing.


Looking at this description I'm starting to think that the behavior isn't really that of a limiter, but more of a 'harmonizer' (harmonization is used in image processing). Basically it just kills excessively loud frequencies.

Lowering "white noise" may not always be bad, it can make some "headroom" where the really loud's can come in. Like old skool recording

btw thanks for all your efforts, ST improves and sounds better all the way over the years!

No, but for actual white noise limiting using this many bands isn't the best possible solution. Anyway I'll make it configurable so the current behavior will still be available.

OOPS i think i had overdone it . If i set it to do less limiting it works "perfect". Sorry for that Hans that was my fault.

_________________
Very proud user of Stereo Tool since 2010. Thanks Hans.

My radio station
http://amradio.ddns.net

Usually good settings is -2dB.. However since there is also clipper, and the idea is to both work together, there is also "Advanced Bass Distortion Protection"settings in Clipper, wich should be at max value same as limit or slightly higher.
For example, limit -2.16dB and "ABDP" to -2.05 (always clip deep bass bellow). "Limit" will not exactly limit to -2.17. so ABDP also slightly do what is need to do.

I hope that my new idea that I described above will make the limiter far less sensitive to the level it's set at.