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ZPlane Fennek

Audio Metering Plug-in By Hugh Robjohns
Published January 2022

ZPlane Fennek

This BS.1770‑compliant loudness meter offers some interesting and original features.

ZPlane have recently launched a successor to their popular PPMulator metering suite. Instead of emulating obsolete but delightful mechanical PPMs, this new audio metering system, called Fennek, is rather more modern and it focuses strongly on measuring programme Loudness in all its attributes — it’s aimed squarely at professional audio‑for‑video applications.

Fennek combines multichannel bar‑graph peak meters (supporting all formats up to 10 audio channels), with various numerical readouts, and a configurable loudness history chart. The GUI is customisable and resizable, and Fennek can be used either as a standalone and self‑contained metering system or as a conventional plug‑in (VST, VST3, AU, and AAX formats, with support for Windows 10 or Mac OS 10.15, and 11.5 for Intel and M1/ARM machines).

Fennek Overview

Naturally, Fennek incorporates the latest complete BS.1770‑related Loudness metering algorithms and associated displays, and all the usual targets and parameters can be configured manually or called up from an extensive collection of built‑in Presets, which align the meter to the published requirements of the world’s broadcasters, Internet Streamers, and other popular audio outlets.

Momentary, Short‑term, and Integrated loudness (LUFS) measurements are calculated and displayed (with variance ranges and maximum values for the Momentary and Short‑term meters to assist in ‘short‑form’ programme assessment), along with Loudness Range, Dialogue Integrated Loudness (and the percentage of dialogue detected in the audio material, per Dolby’s Dialogue Detection algorithm), and True Peak levels.

So far so conventional, you’ll be thinking, and you’d be right. But where Fennek stands out above its peers is in its handling of measurement history. Of course, most loudness meter plug‑ins now include some form of history view, but Fennek’s facilities are — as far as I know — unique in this area, and give this particular plug‑in solution a very useful workflow advantage over its competition.

Most loudness metering plug‑ins can start and stop their measurement process automatically when the DAW is started and stopped, thus ensuring the accuracy of the calculated Integrated Loudness value. While Fennek does that too, of course, it also offers a couple of additional ‘measurement time‑base’ modes. The most basic and familiar of these is the ‘Elapsed’ mode, in which loudness measurements are logged with the digital equivalent of a stopwatch, without any absolute time reference. A second option is called ‘System’, and this relates the loudness logging measurements to the computer’s own system time — this, naturally, is normally the current time of day — so it is akin to logging loudness events against a clock on the wall, identifying precisely when any specific loudness event occurred. This could potentially be useful in real‑time broadcasting, for example.

The Setup screen, where you can make various adjustments to the metering and appearance.The Setup screen, where you can make various adjustments to the metering and appearance.

The Perfect Host?

The third, most innovative mode is called ‘Host’ and this locks the History log time‑base to the DAW project’s own timeline. The benefit of this way of working is that there is always a fixed relationship between the audio arranged across the DAW’s timeline and the calculated Loudness measurements being displayed, and it’s this fixed correlation that allows something ZPlane call ‘measurement session overdubbing’...

What is ‘measurement session overdubbing’ I hear you ask? Well, imagine the scenario where you’re mixing the soundtrack for a long TV programme, and you discover at the end that several small sections exceeded the broadcaster’s loudness or true peak limits. Helpfully, Fennek’s History display reveals the precise time(s) where the measurement tolerances were exceeded — and in a way which is directly relatable to the DAW’s own timeline, so that it’s easy to go back to the identified positions and remix just the offending sections to ensure compliance.

Some other metering systems might already facilitate that, too… but they would then typically require you to run the entire programme back through the metering software all over again to re‑measure the Integrated Loudness and other relevant parameters. This is where Fennek’s ‘Host’ time‑base option really does win out, because its ‘measurement session overdubbing’ completely negates any need for another full measurement pass — potentially saving considerable post‑production time and cost.

Fennek allows you to scroll through the history log and not only obtain readings at any point in time, but also sync your DAW’s transport, so you can attend to problems the metering has indicated.Fennek allows you to scroll through the history log and not only obtain readings at any point in time, but also sync your DAW’s transport, so you can attend to problems the metering has indicated.

In this Host mode, Fennek’s history log data is synchronised to the DAW’s timeline, and by simply replaying across just the remixed section(s) the metering software captures revised measurement data for those sections which is automatically incorporated back into the measurement history obtained during the original pass, and a complete set of updated loudness measurements is instantly available for the whole programme. This innovation is more than just convenient, in many professional situations it could easily be a complete game‑changer!

Where Fennek stands out above its peers is in its handling of measurement history.


As with any new metering system, you’ll need to take a little familiarisation time before you can access all the displays at a glance. But I found Fennek to be a powerful and accurate Loudness meter that’s more up‑to‑date and comprehensively equipped than most, and easy to configure to meet any specific requirements.

I did experience a couple of crashes when used as a plug‑in and in Standalone mode it resolutely refused to acknowledge any ASIO drivers, offering only to work with Windows Audio or DirectSound drivers. Reading the manual, it would seem there are still a few bugs to be ironed out of the Windows version, which I’m sure will be attended to soon, but it seems already to be fully stable in a Mac environment.

The Host time‑base synchronisation function and associated ‘measurement session overdubbing’ capability stand out as the star features. Anyone involved in audio‑for‑video editing or mixing/dubbing could find that Fennek revolutionises the workflow, and that makes this a very attractive new metering solution indeed.


  • Comprehensive loudness metering suite conforming to the latest specifications.
  • Resizable and customisable GUI.
  • Unique ‘measurement session overdubbing’ feature via host timeline synchronisation.


  • Windows platform development appears unfinished.


A comprehensively specified and implemented loudness metering system in which the measurement data can be synchronised to a DAW’s timeline to allow sections of data to be updated to reflect mix changes without having to re‑analyse the entire programme content.


£110.86 including VAT.