Gullfoss by Soundtheory is an intelligent automatic equalizer that balances your mix in real time by modeling how human hearing actually perceives sound.
Most EQs require you to find problem frequencies yourself. Gullfoss listens like a listener: its computational auditory model analyzes the audio hundreds of times per second and continuously adjusts a very high-resolution EQ so that important elements stay audible and masking is reduced. The result is mixes that sound clearer, more open, and more detailed, often with just a few percent of processing.
Engineers use Gullfoss on mix buses and masters to fix muddiness, harshness, and dullness in seconds, and on individual tracks to make vocals and instruments sit better. Two editions are included: the standard Gullfoss for mixing and mastering, and Gullfoss Live with near-zero latency for tracking and live sound. It runs as VST3, AU, and AAX on macOS and Windows.
Gullfoss has earned a reputation as a mastering secret weapon: Grammy-winning engineers have credited it on major releases, and its processing can be auditioned per frequency region so you hear exactly what it is changing. The Clarity parameter, added in later versions, extends the same auditory model to restoring perceived detail in dull or heavily compressed material.
Gullfoss is a one-time purchase of $199 from Soundtheory, including both the standard and Live editions, with a free trial available.
Mixing and mastering engineers, producers, and content creators who want clearer, more balanced audio quickly, whether as a finishing touch or a rescue tool.