When it comes to limiter, there is no clear winner, I have two limiter plug-ins I turn to, the Avid Pro Limiter and the Nugen Audio ISL. Both are true peak limiters but until recently the Nugen ISL was not a DSP plug-in. With the release of the AAX DSP version of ISL2, this is back in my favourites list again.
Just before the release of the Nugen Audio Loudness Toolkit 2 I did a sneak preview of the ISL2..
The new features in the ISL2 take it from a great limiter to an amazing limiter and has been designed to be the perfect tool in both broadcast loudness workflows and music mastering workflows.
Auto Release Hold Mode
Especially helpful for music mastering, there is a new Intelligent Dynamic Release Mode to enhance algorithm transparency by automatically adjusting to program content in real time. The Auto button when enabled allows ISL2 to analyse the incoming audio signal for low frequency content and automatically extend the ‘hold’ time of the limiter to ensure a full wavelength passes before the release cycle is activated. This allows the use of shorter release times than might usually be employed, whilst ensuring that harmonic distortion is not introduced when low-frequencies trigger gain reduction.
Scrolling History View
There is a new section in centre of the plug-in which is accessed by this small H icon. This History mode when active, shows an alternative view showing the gain reduction history displaying the maximum reduction on all the channels going through the plug-in.
Steering and Ducking meters
Steering is a by-product of the action of limiting a stereo or surround signal when you don’t fully link each of the channel limiters whilst Ducking is the inverse effect of steering where other channels are ducked due to high level audio on one channel.
Independent Centre Channel Linking
When ISL2 is used in 5.1 or 7.1 mode, an additional Centre Channel control is available. This control allows independent linking of the Centre channel.
Although the ISL and now ISL2 have been designed to use at little screen real estate as possible, sometimes with a lot of plug-ins in use it would be nice to have a more compact mode and in ISL2 Nugen Audio have added a Compact view.
Only Need Stereo?
Nugen Audio also offers a stereo version of their limiter - ISL 2st Native for Pro Tools Vanilla users and ISL2st for AAX DSP, designed specifically for Pro Tools HDX users who only require mono or stereo capabilities.
Does It Work As A Broadcast Limiter?
The simple answer is YES. It simply does what it needs to do without fuss and without colouring the sound. I have used it on documentaries for BBC Radio 3 that also involve a lot of sound design and its completely transparent. I have also deliberately tried pushing it very hard and it just works even with way more gain reduction than I would normally ever consider using normally.