Back in April Nugen Audio announced Halo Vision, an immersive and surround audio analysis tool supporting channel counts up to 7.1.2. At the time it was slated for release in May 2022 and after some delays, the plug-in has now been released. Designed as a tool for use on 5.1 and 7.1 surround mixes or Dolby Atmos beds, Halo Vision offers a variety of modules which provide professionals with a clearer understanding of phase relationships between channels, detailed information on levels, and visualisations of panning and frequency distribution within a surround mix. All of this is designed to aid users in troubleshooting and pinpointing potential problem areas which might be missed using ears alone. Here’s the lowdown on what Halo Vision provides.

Resizable And Customisable Interface

Conveniently, Halo Vision is resizable by dragging the lower right corner of the plug-in. Also, modules within the plug-in can be selectively shown or hidden as required and resized too. Individual modules within Halo Vision can temporarily be expanded to fill the whole area of the plug-in window when you need to see more detail in a particular view. Halo Vision provides 7 different modules:

Correlation Matrix

The Correlation Matrix shows the phase relationships between channels, using a small square cell meter for each channel pair. Completely in phase channels are indicated in green and completely out of phase are shown in red. There’s also an arched meter in this view which indicates the phase relationship of any chosen pair of channels via a meter which goes from -1 (out of phase) through 0 (no correlation) to 1 (100% correlated).

Correlation Web

As an alternative way to view phase relationships, the Correlation Web displays each channel interconnected with every other channel with a series of lines. When phase relationships anti-correlate, the lines light up. The more out of phase, the more intense the colour.

Frequency Haze

The Frequency Haze shows a top down view of your speaker layout and provides a visualisation of the frequency spectrum. The lowest frequencies are represented in the centre of the circle with higher frequencies being on the outer edge. When using height channels, an additional semi-circular view is shown which indicates the frequency content across those channels.

Location Haze

The Location Haze shows the energy distribution across your surround mix, giving a visualisation of the location of your audio. There’s an additional view when working with height channels, this time in the form of a rectangular box which displays perceived height information.

Spectrum

The Spectrum is an FFT which plots frequency against time. You can view the whole mix summed together in one view or as separate channels differentiated by colour but shown together on the same graph.

Peak Meters

Halo Vision provides a meter for each channel. These can be set to show sample peak, true peak or Apple peak.

Time Code

The timecode display shows the timecode from your DAW. If you really want to, you can change the colour of the hours, minutes seconds and frames displays.

Nugen Halo Vision in use

In testing this plug-in, I first instantiated it on a 5.1 sound effects aux in a Pro Tools session. It’s pretty easy to interpret the information on display and the scalable interface meant that I was able to tailor it to fit my available screen space and to hide the modules which I don’t need. I encountered a couple of GUI glitches when switching displays or resizing, as you might notice in the video, but this was a pre-release version of the software and the glitches are not present in the final release version. The modules are responsive and give a clear view of the information they display.

Nugen Audio describe Halo Vision as providing comprehensive analysis for 3D and immersive audio. One thing to think about when considering purchasing Halo Vision is that it supports channel counts up to 7.1.2 and can be used on channel based beds but not on objects. This is a limitation of how Pro Tools works along with the Dolby Atmos Production Suite so you can’t use Halo Vision to view information about a whole Dolby Atmos mix, just individual beds.

Expert Panel - Hit or Miss?

In every Expert review we ask three of our team of contributors to give their first impressions of the product. We ask them to give the product a hit or miss, based on factors such as originality, innovation, usefulness, quality and value for money. For each hit the products gets an Expert Award. One hit and it gets our bronze award, two hits gets silver and for a hit from all three of the panel it gets a coveted gold award. Of course if there’s three misses, there’s no award.

Paul Maunder on Nugen Audio Halo Vision

I’m currently working on the audio for a feature film which I’m mixing in 7.1. I have to admit that I’ve never felt that I needed a plug-in such as Halo Vision but having now used it for a few weeks, I have actually found it quite useful. The location haze is the part which I’ve found myself referring to the most as I’ve found that it gives me an extra bit of feedback on what’s going on spatially with the mix. I’ve had to do some of the work at home where I only have the facility to monitor in 5.1. This means that I’m listening to a downmix of the 7.1 so the extra visual information provided by Halo Vision has been of benefit.

I haven’t found that I particularly need the correlation web or correlation matrix as I don’t generally encounter large problems with phase issues when working on surround mixes. I can see the potential though and given that I’ve been utilising the location haze quite a bit along with the frequency haze from time to time I’m going to say that Halo Vision is a hit for me. I’m not working in Dolby Atmos yet, so for 7.1 content, I’ve found this to be a good tool.

Roger Guerin (CAS, MPSE) On Nugen Audio Halo Vision

I was pretty excited in trying out Nugen Audio’s new effort in what they call Halo Vision, a Visual Analysis Suite for Surround and Immersive Audio. If it says Immersive I am in. What this new plugin does is quite an ingenious idea. Of course it measures the True Peaks on all channels, but it even displays the phase relationship between two, user selectable, signals. A feature not to be neglected when you are downmixing to stereo let’s say. Trying to hunt down that “phasey sound” could be a time-consuming task.

I am new to Nugen so their GUI is quite an innovation to me, and being able to resize any window with that ease is simply elegant. Of note, their Spectrum display is really something, you can group signals and determine offending frequencies in a snap, now that I would use every day.

Understandably it is still in its early stage so we have to excuse some slips, for example in Pro Tools instead of giving the correct Timeline’s reading, their Time Code Reader only kicks in when there’s actual audio, otherwise it just sits there waiting, leaving the user with the sensation that something is wrong. Additionally, with the improbable presence of 23.976DF and the absence 23.976, I am confident it will be revisited real soon.

Furthermore, I know it would be difficult, but unfortunately it does not take into account the “objects” nor does it have a Loudness reader, but then they have the VisLM for that last one. All in all a plugin that I would keep my eye on, but this version it is a miss.

Nathaniel Reichman On Nugen Audio Halo Vision

I had an album project recently where I was quite confident in the quality of the immersive Atmos mix, but the stereo re-render mix exhibited some wild phase issues. On many past album projects, the stereo mix was done separately from the Atmos mix, but on this album I really liked how the stereo re-render sounded, so I needed to address the phase issues. Nugen’s Halo Vision would have been handy for this, since it displays phase between any channel pair in a 7.1.2 or 7.1.4 mix in a visually clever way, using their “Correlation Web” and “Correlation Matrix” (the top left polar pattern and the yellow triangle, respectively in the picture). These meters alone are worth the price of admission. However, in the most common Pro Tools/Dolby Atmos Production Suite workflows, it’s a little tricky to figure out where Vision should go. There’s no way to put it across your entire mix in Pro Tools, since that can span 128 channels. And if you put it on a bed, then you’re obviously missing the other beds and all your objects.

After some thought and experimentation, I used Core Audio to patch the output of the Dolby Atmos renderer into Logic, where I could route my entire 7.1.4 mix in on auxiliary tracks. This was limiting, but it allowed me to see the entire mix going into Vision. In the coming weeks, I will likely put Vision on a dedicated computer and send a 7.1.4 re-render to it for metering. But obviously, not everyone is running dual-computer rigs, so Vision may be of limited use in smaller Pro Tools setups. My recommendation is to demo the plug-in before you purchase it, since the routing is a tricky problem to solve. But I expect Halo Vision to be quite useful to mix engineers that need more visual feedback than we currently get from the Dolby renderer. Hit or miss? Tough to say, but until the routing question is worked out better, it’s a miss.