05) Attack & Release of an Acceleration Limiter
HiFAL uses a sophisticated, sample-by-sample approach to compression that dynamically adjusts attack and release times based on the amount of gain reduction. While computationally intensive, this process results in exceptionally smooth and transparent high-frequency limiting. As gain reduction increases, the attack and release accelerate in response to the signal. This dynamic movement is the core idea behind HiFAL: a high frequency limiter that doesn’t just react, but adapts in real time.
Because the timing constantly changes in response to the input signal and threshold, HiFAL does not offer user-definable attack and release controls. Fixed values wouldn’t behave meaningfully in this context. Instead, HiFAL delivers natural-sounding dynamic control without too much manual adjustment.
The actual timing behavior shifts significantly depending on how much gain reduction is taking place. When gain reduction is subtle, the limiter responds with a slower, more relaxed feel, both in how it ramps in and how it lets go. As the gain reduction increases, the response becomes noticeably quicker and more immediate. If you watch the gain reduction meters, you’ll notice the speed changes between each gain reduction light. While those lights don’t directly represent compression times, the meter gives a visual sense of how the movement accelerates as the reduction increases. This kind of adaptive timing is a defining part of HiFAL’s sound, and it’s intentionally difficult to quantify, since the attack and release are continuously shaped by the signal itself.
In Practice:
For a full mix, I usually start with a slow attack and a fast release. I set the threshold so the first gain reduction light is just barely glowing during an average loudness section of the song. Then, during bursts of harshness, you’ll see quick flashes of gain reduction. If a mix or element feels particularly pokey and needs tighter control, I switch to a fast attack. With this setting, the gain reduction meter reacts much faster and helps tame more of the harshness. For the most transparent result, try a slow attack and a slow release, with a slightly lower threshold than the previous setting. You can think of the first gain reduction light as a guide for setting the threshold. The attack is slow enough to let the natural dynamics through. If a harsh transient appears, HiFAL will soften it and then quickly return to letting the natural high-frequency dynamics pass.
Be well,
Ryan Schwabe
Grammy-nominated and multi-platinum mixing & mastering engineer
Founder of Schwabe Digital
