IK Multimedia T-RackS Stealth Limiter

T-RackS Stealth Limiter is an ultra-transparent mastering peak limiter. It's a versatile sonic ninja of a mixing and mastering tool that features an advanced inter-sample peak limiting algorithm that lets you turn up the loudness of your mixes while still maintaining a clean a sound that’s full of dynamic range and sonic breathing room. T-RackS Stealth Limiter is your new go-to mastering peak limiter when you want impressive loudness without the damaging side effects of traditional processors.

The loudness wars

The past few decades have seen volume levels rise at an alarming rate. Loudness of mixed and mastered audio material has become a de-facto standard for contemporary music production. This quest for loudness has come at a significant cost - as producers and engineers strive to remain competitive they employ methods of extreme compression and limiting that, though they make a mix louder, also impart an unmistakable mark of residual distortion, sonic flatness and loss of overall emotion. When used heavily, these processors flatten out the music’s dynamics and get rid of much of the music’s magic and emotion when passing between various sections of a song. Our goal was to provide a new kind of processor for the final peak limiting stage of the mastering process that’s able to impart loudness while maintaining more perceived dynamic range than other limiters and compressors.

A stealth weapon

At a basic level, T-RackS Stealth Limiter provides an impressive increase in loudness without the discernable effects of compression. Simply put, it's the most transparent, clear and loud software mastering peak limiter available. And this is all thanks to its smart level-tracking algorithm. It works under the hood to reduce levels below the volume ceiling moment-by-moment instead of applying traditional look-ahead envelope-based fast attack compression. This algorithm doesn’t sound like a compressor, and that’s because it’s not a compressor! T-RackS Stealth Limiter’s algorithm tracks the level and keeps it under control while simultaneously preserving the perceived sense of dynamics.

A new approach

With traditional mastering processes, it's normal to push the volume level towards a -0.1dB or even 0.0dB ceiling. Spikes above this ceiling are suppressed via the use of hard limiters and clippers. Yet these methods only ensure a stable digital level, they do not guarantee undistorted playback once the music is translated into an analog signal.

This is because the process of playback involves a number of conversion processes that, though the digital waveform may be below 0.0dB, can cause the analog waveform to exceed this threshold and introduce unwanted distortion and fuzz.

T-RackS Stealth Limiter features an inter-sample peak-limiting algorithm that gets around this issue by predicting the converted analog waveform of the digital source. Through this process, it's able to limit the sound in a way that ensures the final converted audio will very rarely exceed the set ceiling. This is useful in the modern era where music is often heard on different devices and via different services that all deliver their music via compressed formats, like MP3 or AAC.

Easy to use

Using T-RackS Stealth Limiter couldn't be easier. It sports straightforward controls and intuitive features that let you apply its powerful processing to your mixes quickly and effectively. Just use the input knob to set the input level to your desired loudness, and then adjust the output level with its output ceiling knob.

Advanced stealth modes

T-RackS Stealth Limiter gives you a suite of advanced controls that are custom tailored for fine-tuning. It sports 4 modes that can each be used for a different mastering purpose:

TIGHT
This is T-RackS Stealth Limiter’s default mode, and it’s most neutral. It respects the source material’s natural sonic dynamics the most. Even when set to the highest limiting setting, the music will never sound “compressed” or “constrained.” With this setting, you can increase loudness while maintaining a neutral effect on sonic timbre and dynamics.

BALANCED
Like its name suggests, this is a more balanced process that can be used when a small amount of dynamic compression is acceptable (or desirable). The difference between this mode and TIGHT is so subtle that the two are only distinguishable at high loudness levels and with extreme limiting.

HARMONICS 1
Though designed to be ultra-transparent, T-RackS Stealth Limiter can also be used in this mode to add a dash of harmonic coloration and sonic enrichment to the processed audio. When engaged it conveys a sense of dimension and pleasant coloration to your mix that will make it sound and feel more analog.

HARMONICS 2
Similar to HARMONICS 1, this mode is also used for adding a bit of sonic character. The difference though is that HARMONICS 2 lets you add some grit and punch when you feel that your music is weak or needs a more thorough boost of analog character.

In addition to these modes, you also get an onboard unity gain monitoring function that lets you listen to your mix's processed audio without the accompanying increase in volume. This makes it easy to instantly compare processed and unprocessed audio so that you can ensure you avoid the "louder is better" pitfall.

T-RackS Stealth Limiter also comes with an infrasonic filter (a 22Hz, 4th order high pass filter) that can be engaged to cut out unwanted sub-bass frequencies from your mix that could put an excessive workload on the limiter.

Combine these advanced features with T-RackS Stealth Limiter's ability to transparently provide mix loudness, and you have a secret weapon of a mastering tool that you'll find yourself reaching for again and again.