Nugen Audio Halo Upmix is a powerful and versatile plugin designed for upmixing stereo audio to surround sound formats. It allows audio professionals to convert stereo material into 5.1, 7.1, and with the optional 3D Immersive Extension, even 7.1.2 and 7.1.4 configurations for Dolby Atmos and Auro 3D. The plugin employs advanced algorithms to analyze the original stereo content and create a natural-sounding surround field without introducing artificial reverb, chorus, or delays. This preserves the integrity of the source material while expanding its spatial presence.
Pros:
• Natural-sounding upmix without artificial artifacts
• Intuitive visual interface with real-time feedback
• Powerful center channel control with dialog extraction
• Exact downmix compatibility mode
• Flexible output formats up to 7.1.4 with 3D extension
Cons:
• Relatively high price point compared to some competitors
• 3D Immersive Extension sold separately
Halo Upmix features an intuitive interface with a circular radar-like display that visually represents the surround sound field. As audio plays, the plugin shows real-time energy distribution across channels using color-coded clouds. This visual feedback allows users to quickly assess how the upmix is affecting the spatial characteristics of the audio. The plugin offers precise control over various parameters, including surround width, center channel management, and low-frequency content.
One of Halo Upmix’s standout capabilities is its center channel management, which includes a neural network-based dialog extraction feature. This allows users to isolate and control dialog or central elements of a mix independently, which is particularly useful for film and TV post-production work. The plugin also includes an “Exact” mode that ensures perfect downmix compatibility, preserving the original stereo mix when folded back down from surround.
Halo Upmix offers a comprehensive set of features designed to give audio professionals granular control over the upmixing process. The plugin’s core functionality revolves around its proprietary algorithms that analyze the input stereo signal and intelligently distribute audio elements across the surround field.
The main interface is dominated by the circular “Haze” view, which provides a top-down representation of the surround space. This visual element dynamically updates as audio plays, showing the intensity and directionality of sound using color-coded clouds. Users can customize the colors for each channel, making it easy to identify which speakers are receiving specific audio content.
Surrounding the Haze view are various controls that allow fine-tuning of the upmix. The Width control adjusts how far the stereo image is spread into the surround channels, while the Depth parameter affects how much content is sent to the rear speakers. These controls use an intuitive arc-based interface, allowing users to visually set the boundaries of the surround field.
The Center Channel Management section is particularly noteworthy, offering advanced control over how center-panned content is handled. The neural network-based dialog extraction feature can isolate vocal content, allowing it to be treated separately from other center-channel elements. This is invaluable for maintaining clarity in dialog while still creating an immersive surround experience.
Low-frequency management is another key feature, with dedicated controls for adjusting how bass content is distributed between the main channels and the LFE (Low-Frequency Effects) channel. This ensures that the low end remains tight and controlled in the upmixed result.
The 3D Immersive Extension expands Halo Upmix’s capabilities to include height channels, enabling upmixing to formats like 7.1.2 and 7.1.4. This extension also adds support for Ambisonic output, making it useful for VR and 360-degree audio applications.
Halo Upmix includes a comprehensive set of presets that cater to various upmixing scenarios, from subtle ambiance expansion to full cinematic treatments. These presets serve as excellent starting points that users can then customize to suit their specific needs.
The plugin also features an “Exact” mode, which ensures that when the surround upmix is folded back down to stereo, it precisely matches the original input. This is crucial for maintaining compatibility across different playback systems and broadcast scenarios.
For more detailed adjustments, Halo Upmix offers an advanced view that provides access to individual channel controls, allowing users to fine-tune the balance and characteristics of each surround channel independently.
In the realm of upmixing plugins, Halo Upmix competes with offerings like Waves UM225/226 and iZotope Ozone Imager. Compared to these, Halo Upmix generally offers a more natural-sounding result with less artificial coloration. Its center channel management and dialog extraction capabilities are particularly advanced, setting it apart from many competitors. Where Waves’ solution might be praised for its simplicity and iZotope’s for its integration within a larger mastering suite, Halo Upmix strikes a balance between depth of control and ease of use. Its visual feedback system is more comprehensive than many competitors, providing a clearer picture of how the upmix is affecting the audio. However, Halo Upmix is generally more expensive than some alternatives, especially when factoring in the 3D Immersive Extension. This higher price point is justified by its professional-grade quality and feature set, but it may put it out of reach for some smaller studios or individual users.
This plugin is best for:
• Post-production engineers working on film and TV projects
• Music producers creating surround mixes from stereo sources
• Broadcast professionals preparing stereo content for surround broadcast
• Game audio designers needing to upmix stereo assets for immersive environments
• VR/AR content creators requiring Ambisonic audio from stereo sources
Nugen Audio Halo Upmix stands out as a professional-grade solution for creating high-quality surround upmixes from stereo sources. Its strength lies in its ability to produce natural-sounding results that maintain the integrity of the original mix while expanding it into a wider spatial field. The plugin’s intuitive interface, coupled with its powerful visual feedback system, makes it accessible to both seasoned surround mixers and those new to multi-channel audio. The advanced center channel management and dialog extraction features are particularly valuable for post-production work, allowing for precise control over critical elements like vocals and dialogue. The inclusion of the “Exact” mode for perfect downmix compatibility addresses a common concern in broadcast and multi-format release scenarios.