Audio, Reviews

NUGEN Audio Audio Management Batch Processor AMB

NUGEN Audio is well known for its broadcast audio plug-ins and applications. Recently, it released the Halo Upmix plug-in that turns your stereo audio in any of several 5.1 or 7.1 surround sound standards. And even more recently it released its first batch processor, Audio Management Batch Processor (AMB). This stand-alone app processes multiple audio files simultaneously. Its primary concern is to report on loudness levels, its secondary to auto-edit your audio files to make them comply with loudness standards. A third module will upmix your audio using the new Halo Upmix algorithm. AMB will optionally also work with ProRes and MXF files (OP-1a and OP-Atom).

NUGEN Audio AMB Processor

The NUGEN Audio AMB app is first and foremost a reporting app. It reports the loudness characteristics of your files. It’s a queue based app with settings you can change for every queue you run. You can run queues serially or in parallel. When you run queues in parallel, your audio files will be processed through each queue’s settings simultaneously with different files output from the same source as a result.

In addition, the standard version of Audio Management Batch Processor can batch process files to industry loudness standards. You can also use this module to process audio to loudness settings of your own making. Finally, in its current state of development, AMB has two extra modules you can buy a licence for: upmixing and ProRes capabilities.

The upmixing module works with NUGEN Audio’s Halo Upmix technology. Halo Upmix is available as stand-alone application. If you have Halo Upmix on your system, you can make AMB load the presets you create in Halo Upmix. That is currently not very elegant — it requires you to copy preset files in the Finder — but if you’re a seasoned Mac user, you won’t find it too troublesome. The ProRes module has no settings at all. It just works.

Loudness correction

NUGEN Audio’s Audio Management Batch Processor has a flexible licensing system. When you buy a standard licence, you’ll get two queues and two threads. If you need more power, you can buy extra queues and threads. My test licence came with seven queues and nine threads. I started with one queue and must say the app was blazingly fast processing 993 small files (typically between 10sec and 3min). As the Audio Management Batch processor app is aimed at large production houses or broadcast companies, it’s more realistic to have the number of queues and threads NUGEN Audio set me up with for testing, as they will probably want to run thousands of files a day.

Loudness reporting and correction

AMB’s reporting functionality saves a detailed text or XML report into a folder you define per queue. If you want, you can also have the app generate and save a graph image with full loudness information in PNG format. To comply with loudness industry standards, you can correct files to six industry standards. Correction can work both ways — up for very quiet files and down for loud files. In addition, you can auto-adjust the dynamics of the file using NUGEN Audio’s excellent DynApt 1 algorithm. Three types are supported: TV, podcast and custom. One word of criticism: to correct your files you must check the Auto-correct checkbox, otherwise the app will only report on loudness. The checkbox should be in a more prominent place. I missed it every time I took to testing the app again.

The loudness graph

If you choose to correct your files both upward and/or downward, the application will process them. In some cases, this process will be iterative, meaning it will apply corrections you have set in the Queue Settings window until the file complies with the desired loudness settings. This iterative correction can happen but I must add it is unusual in common usage. It only happens if the limiter is very active during the processing. That usually only happens if you are correcting audio to be much louder than you would normally go for.

Regardless, AMB never introduces sound artefacts. The end result of all the files I put through AMB’s audio processors was impeccable, even the noisiest ones. Depending on your hardware it may take some time, though.

Audio Management Batch Processor queues

NUGEN Audio AMB has a tabbed interface. Each tab represents a queue. Each queue has its own settings. Having multiple queues means you can have AMB process files differently, all simultaneously.

AMB log file

Audio Management Batch Processor allows you to process files automatically as soon as you or another app dumps them in a watch folder — or straight in the queue window. You can then route processed files to any folder you designate in the queue settings. I tested to see if I could set up chain processing, where you start with adding files to one watch folder and route them to the watch folder of the next queue, and so on. It worked fine. You do need to think over your File Handling settings carefully.

You can also send files to all queues at once by dropping files in the “All Queues” tab that automagically becomes available if you have multiple queues set up. Such a workflow would make a lot of sense if you use the same audio files for different purposes. For example, having a queue for DynApt for TV and another for podcasting lets you output both results at once. This too worked like a charm.

The AMB extra modules

Upmixing worked like a charm too. You can upmix to new files or “inline”. The latter requires an audio file with enough channels to contain the upmixed audio. There’s an option to configure the routing of channels from the original file. The process is pretty straightforward.

Having said that, the upmixing feature results in perfect sounding files, with a distribution of loudness across the channels, depending on your settings. Of course, it’s never going to be the 5.1 or 7.1 sound you’ll get from using an appropriate number of microphones, but the results are stunningly good.

Upmix module

The ProRes and MXF modules allow you to natively process video files with metadata and PCM audio. When correcting for loudness you’ll end up with video files that comply with the settings you selected for the queue. However, if you choose to upmix the video file to a new file, you will end up with a WAV audio file, which you can then use to replace the original recorded audio. If you instead upmix in-line by providing a video file with at least eight channels, then it can insert the new upmixed audio into the existing MOV.  If you do it that way, AMB can apply loudness correction to both the original stereo and the upmixed audio all within a single queue.

There’s nothing special to set for ProRes files — it just works. MXF files have a few options you can set, such as whether you want to update the metadata and/or enable AS-11 UK DPP checks.


NUGEN Audio AMB Processor is a must-have for any audio engineer who needs to batch process audio and video files. It’s squarely aimed at broadcasting companies, streaming services and production houses. I think even small online providers of sound effect files and music to go with movies and video could benefit from NUGEN Audio AMB Processor.

The core NUGEN Audio AMB Processor app costs around €799. Extra queues and threads cost €399/pc.

  1. NUGEN Audio’s customer SBS Broadcasting, one of the three leading broadcast networks in the Netherlands, was shortlisted for the IBC2015 Innovation Awards. Nominated in the Content Management category, SBS was recognised for its use of NUGEN Audio’s DynApt algorithm to create a groundbreaking loudness-normalized workflow for film soundtrack adaptation. (See: https://www.NUGEN