A limiter is really just a high ratio compressor, right? Who needs features? Threshold, and maybe some look-ahead, but that’s it. Right? Wrong!
The modern limiter is loaded with options and ready to milk some impossibly hot levels out of your tracks. Case in point: IK Multimedia’s Stealth Limiter, a new plug-in with some advanced abilities. As part of IK’s T-RackS CS Custom Shop, or sold individually, Stealth is meant to be the final step in your mastering chain, although that doesn’t preclude it from mixing work as well. It is not “look-ahead” based, nor a “fast compressor,” but rather a processing intensive, zero-overshoot, brick-wall limiter.
The Stealth’s threshold is fixed; users increase input level to cross the threshold point and commence limiting. An output level control can be set lower than 0 dBFS to ensure there are no inter-sample peaks (e.g., where two adjacent samples of full scale result in an output level greater than maximum, possibly driving converters or analog circuitry into overload); or, two levels of ISPL (Inter Sample Peak Limiting) can be engaged, preventing such overs. Your DAW’s dithering can be selected via Stealth, down to 24 or 16 bits. Unity Gain monitoring is selectable, as is Infrasonic Filter (a 22 Hz high-pass filter, removing rumble) and even four modes of saturation.
Stealth’s Tight mode offers no coloration; Balanced seems to very lightly smooth out high frequencies and transients; Harmonics 1 brings in a bit of subtle saturation; and Harmonics 2 continues that saturation with just a touch of grind and grit.
Despite a deep feature set, Stealth is super easy to implement and achieve good sounds. Applied to a mix, I simply raised input level until Stealth began to kick in with fullness and density, with metering amply telling the full story. I applied Unity Gain monitoring to make sure I wasn’t simply “liking the increased volume” as our ears always do (I wasn’t.) Then I engaged ISPL and was happy to not hear any degradation; in fact I was able to dial in a lot of gain before I got Stealth to max out and hear the limits of such processing.
Selecting saturation modes proved to be much more complicated. Tight works quite well and allows lots of attenuation without any audible distortion. If invisibility is what you want, then you’ll be satisfied with this mode. Compared side-by-side with three popular limiters in my kit (Universal Audio’s $199 Precision Limiter, Waves’ $299 L2 and Joey Sturgis Tones’ $59 Finality Advanced), I was able to get superhot levels cleanly from Stealth that typically exceeded the pack. Results varied song by song, but Stealth with ISPL engaged seemed to get louder before “phlegmy-ness” and excel with low-end heavy material like EDM or rap.
If just a little saturation is your desire, then Balanced will delight you. It’s almost a “polite” button, as it does this pretty softening of content that flatters in an analog kind-of way. It’s strangely subtle yet obvious at once (at least to this engineer’s ears) and is right at home if you’re into that “slightly dark, rather leveled, but sounds great when super loud” mastering timbre that is so popular within EDM-based/DJ pop today.
The Harmonics modes continue Stealth’s quest for maximum average level with the ability to further contain dynamics and sneak in just a touch of distortion. Mode 1 really is subtle, whereas Mode 2 is much more audible and both are useful in a modern context. Mode 2 would be useful in making masters but perhaps more useful on subgroups where drums, guitars, basses, keys and even vocals can be plumped up, rounded off and given a hint of 5 o’clock shadow to taste. Saturating modes (absent from my UA and Waves limiters) are also found in JST’s Finality (again, in two flavors) and are a little different than Stealth’s character. I’ll use both in my work, thank you very much; listen to these audio clips for some examples of Stealth at work on drum kit.
At $125, Stealth finds itself in the middle of the “premium software limiters” price pack and definitely a contender. If you had to own only one software limiter, I could recommend the Stealth for its tonal flexibility and wealth of options. If “grindy” sounds are your forte, then I’d put Stealth alongside Finality (which also has a side-chain HPF that is quite useful on subgroups) for musically useful colorations. And for sheer, clean level, I’ll give it to Stealth for its distortion-preventing ISPL feature. Next, I’d like to compare Stealth to some multi-band limiters.