Spectral Leveler by Kojima Audio

Spectral Leveler is a macOS spectral dynamics plug-in (AAX / AU / VST3) that lets you shape audio by frequency window and level window directly on a real-time spectrogram. Adjust the target range, then control Gain, Attack, and Release for smooth, selective leveling.

What it does

• Display a real-time spectrogram while audio is playing.
• Set a frequency window (upper / lower bounds) directly in the display.
• Set a level window with the color level bar (target only the desired dB range).
• Apply spectral gain with Attack / Release smoothing for natural control.
• Useful for dialogue harshness, sibilant bands, resonant peaks, and transient-heavy sources.