Type X is a faithful emulation of the dbx 1BX, a 1978 single-band dynamic range expander that increases the difference between quiet and loud passages. It adds sidechain filtering and adjustable attack/release for modern production flexibility.
Purpose and Heritage
Type X recreates the dbx 1BX, a compact dynamic range expander from 1978 built for consumer hi-fi playback. Its original role was to restore dynamic range lost in compressed sources like tape, vinyl, and FM broadcasts, making quiet parts quieter and loud parts louder. The effect adds life, punch, and presence to audio.
The hardware offered adjustable expansion up to a 1.5:1 ratio, delivering up to a 50% improvement in stereo dynamic range. AudioThing’s plugin keeps this core behavior while adding modern controls for attack and release, plus a filtered sidechain, making it useful beyond the original playback-focused scenarios.
Core Dynamics Processing
Type X applies wideband dynamic expansion using a true RMS detector to track signal energy over time, just like the original. When the input crosses a user-defined transition level, the expander adjusts gain based on the expansion ratio. Adjustable attack and release shape the response speed, giving you control over how aggressively or gently the expansion reacts.
Unlike a compressor, the plugin increases the difference between soft and loud content, so quiet sounds get quieter while loud material stays prominent. This makes tracks feel more dynamic and expressive. The single-band design processes the full frequency range together, maintaining coherence while adding contrast.
Sidechain and Shaping
A key modern addition is the sidechain input, which lets you drive the expansion from an external signal instead of the main input. Dedicated high-pass and low-pass filters sculpt which frequencies trigger the detector, so you can focus expansion on specific elements like a kick drum or vocal presence. A Gain control adjusts sidechain level independently.
The sidechain can be sourced from the main input or an external path, and a source listening function lets you monitor exactly what the expander hears. Brightness and Contrast controls further shape the output character, providing tonal adjustments beyond the original hardware. Oversampling up to 16x helps maintain quality when processing high-frequency material.
Practical Workflow
In a session, Type X works well on individual tracks or buses needing more life. For drums, set the transition level to catch quieter hits and increase attack for punch. On vocals, slower release times can smooth out level variations while maintaining energy. The sidechain can trigger expansion from a synth or bass to create pumping or breathing dynamics.
For mastering or mix bus use, apply subtle expansion to restore dynamics in overly compressed mixes, especially those from tape or digital limiting. The resizable window and preset system with randomizer help quickly find starting points or explore creative settings. Loading a preset and tweaking the transition and ratio gives immediate results, and randomizer assists in discovering unexpected but usable configurations.
Key features
- Single-band wideband dynamic expander
- True RMS detector for signal analysis
- Adjustable attack and release times
- Sidechain input with high-pass and low-pass filters
- Oversampling up to 16x
- Brightness and Contrast controls
- Preset system with randomizer
Best for
Best for adding dynamic contrast to drums, vocals, or full mixes, especially those suffering from over-compression. Also useful for creative sidechain effects or restoring life to tape, vinyl, or broadcast audio.