processing with High Dynamic Range (3)

This article explores how some different HDR imaging alike techniques can be adopted right into the audio domain.

The early adopters – game developers

In the lately cross-linked article “Finding Your Way With High Dynamic Range Audio In Wwise” some good overview was given on how the HDR concept was already adopted by some game developers over the recent years. Mixing in-game audio has its very own challenge which is about mixing different arbitrary occurring audio events in real-time when the game is actually played. Opposed to that and when we do mix off-line (as in a typical song production) we do have a static output format and don’t have such issues of course.

So it comes as no surprise, that the game developer approach turned out to be a rather automatic/adaptive in-game mixing system which is capable of gating quieter sources depending on the overall volume of the entire audio plus performing some overall compression and limiting. The “off-line mixing audio engineer” can always do better and if a mix is really too difficult, even the arrangement can be fixed by hand during the mixing stage.

There is some further shortcoming and from my point of view that is the too simplistic and reduced translation from “image brightness” into “audio loudness” which might work to some extend but since the audio loudness race has been emerged we already have a clear proof how utterly bad that can sound at the end. At least, there are way more details and effects to be taken into account to perform better concerning dynamic range perception. [Read more…]

announcing the “Slick” audio plug-in series

About history

In recent history, I’ve constantly extended and improved my Stateful Saturation approach and within ThrillseekerVBL I’ve managed to introduce authentic analog style sounding distortion right into VST land, which is what I’ve always had in my mind and dreamed of. And there’s so much and overwhelming feedback on that – thank you sooo much!

Best of both worlds

Since quite a while, I’ve dreamed about a brand new series of plug-ins which will combine the strength of both worlds: analog modeling on the one side but pure digital techniques on the other – incorporating techniques such as look-ahead, FIR filtering or even stuff that comes from the digital image processing domain, such as HDR (High Dynamic Range) processing.

First encounter: SlickHDR

High Dynamic Range (HDR) processing is something pretty much new in the audio domain. While there are lots of theories and implementations available about HDR imaging, this is quite new and sparingly adopted in the audio domain. SlickHDR is going to be a very first approach in applying high dynamic range processing to audio within a VST compatible plug-in.

compressor gain control principles

A short compendium on digital audio compression techniques.

Basic compressor configurations

Compression vs. limiting

Technically speaking the same principles are used in audio signal limiting and compression processors but just the transfer curves and envelope follower settings are different. Ultra fast attack rates and high ratio amounts are used for limiting purposes which causes just very few peaks to pass on a certain threshold.

In digital implementations limiting processors can be more strict due to look-ahead and clever gain prediction functions which guarantees that no peak information passes the threshold. That is called brickwall limiting then.

[Read more…]