A frequency-sensitive noise suppressor and dynamics tool with three independent expanders and a phase-coherent crossover, ideal for cleaning up tracks.
Purpose
Metric Halo Multiband Expander v4 is a three-band processor designed to manage, suppress, and control noise in audio tracks. Its phase-coherent crossover network splits the signal into three bands, each routed to an independent expander. You set the threshold for each band, and the expander smoothly attenuates audio below that level. This allows for precise noise reduction, such as removing hum or hiss, without compromising the desired signal.
The multiband design is particularly effective for guitar tracks, where noise can be attacked more aggressively than the musical content. It can also be used creatively to alter rhythmic feel by suppressing softer-played elements in a frequency-specific manner. The expander is not a mixing necessity but a targeted tool that solves specific problems effectively.
Key Capabilities
Each band features a dedicated expander with adjustable threshold and ratio settings (inferred from the general expander functionality). The crossover points are easily adjustable using the built-in SpectraFoo spectral analyzer, which provides visual feedback for setting precise thresholds and crossover frequencies. Additional processing includes a two-band parametric filter for shaping the delayed signal, and the MH Character circuit adds saturation and texture.
The v4 update introduces native Apple Silicon support and a VST3 version for both macOS and Windows, offering full compatibility with modern hosts. All plugins support AU, AAX, VST2, and VST3 on macOS, and AAX, VST2, and VST3 on Windows. UI enhancements include adjustable resizing, user-configurable themes, knob styles, band colors, and UI colors, plus the ability to show or hide knob rings.
Workflow
The workflow leverages the SpectraFoo analysis to quickly identify noise frequencies and set crossover points. Users can listen to each band individually to fine-tune thresholds, ensuring that only unwanted noise is suppressed. The expander’s smooth response avoids audible pumping artifacts. Presets are available to provide starting points, and the MH Preset Manager allows for cross-platform preset sharing.
v4 adds practical features for professional use: undo/redo, A/B snapshots with blend capability, and software update tracking. Plug-in settings can be copied and pasted between instances, and a details pane (accessed via the MH logo) provides links to documentation, tech support, FAQs, release notes, and preferences. The installer download size is significantly reduced on macOS, and the interface is more flexible in resizing with common controls in the header bar.
Practical Applications
Multiband Expander is ideal for cleaning up guitar recordings by removing hum and noise while preserving the guitar’s tone. It also works well on vocals, drums, or any track with background noise, allowing for frequency-specific suppression. In a creative context, it can subtly alter the dynamics of rhythmic parts by reducing soft notes, adding a unique character.
The tool is particularly useful in post-production for dialogue or ADR cleanup, where noise can be targeted without affecting speech intelligibility. For sound designers, it offers a way to shape ambient recordings by reducing low-frequency rumble or high-frequency hiss. While not needed in every mix, it proves valuable when a mix needs precise noise control.
Key features
- Three independent expanders with a phase-coherent crossover network
- SpectraFoo spectral analysis for accurate crossover and threshold setting
- Two-band parametric filter for shaping delayed signal
- MH Character for saturation and texturing
- Undo/redo, A/B snapshots with blend
- Cross-platform presets via MH Preset Manager
- VST3 and native Apple Silicon support in v4
Best for
Best for audio engineers and musicians who need to suppress noise or hum in a frequency-targeted way, especially on guitar tracks, and want creative control over rhythmic dynamics without affecting the core signal.