“Films are 50% visual and 50% sound.
Sometimes sound even overplays the visual.”
David Lynch

There are many quotes on how important sound is in films. Many of us, myself included, would go further than Lynch and say that audio is almost always more important than visuals in the experience of the viewer. Show someone a documentary where they can hear the dialogue clearly with blurry or shaky visuals. Then show one with pristine shots and terrible audio and see which one has the most impact.

This speaks to the importance of the audio team – from getting the right sound on the shoot, through to the mixing process in post. But it’s also a big part of the offline editor’s job – to sell the cut with good temp sound design and a good temp mix – this can make all the difference in getting things signed off. And of course at the lower budget end, many editors won’t have the money to hand over their audio to a dedicated sound editor. These are a couple of examples where the standalone app End Boost might prove useful.

What is End Boost?

The basic idea is an automatic one button audio mix. Perhaps that sounds too good to be true, but frankly it works pretty well. That’s not to say that it does everything.

There’s no automatic EQ (yet) and the noise reduction (which is in Beta) is not quite up to the standards of the leading plugins. It’s also not going to do cleanup for you – removing clicks and pops and rustle.

What it will do however is provide a custom AI mixing algorithm get the right levels of gain and compression on your dialogue with the right amount of ducking on your music and sound effects/atmos, to deliver a pretty professional sounding mix. These are things you can do yourself in your NLE of course if you know how – the point is they take time.

Née Alex Audio Butler

née      /neɪ/      adjective
“originally called; born”

End Boost is a continuation of the plugin Alex Audio Butler from Dutch developer Jerre van der Hulst at his company Unimule. Alex Audio Butler was a set of VST plugins that you’d apply to dialogue, sound effects and music in the Track Mixer and it would automatically mix the levels for you. I tried it out for a while and it was pretty good, though it had its downsides. Mainly that levels would jump around a bit when you pressed play as it did its calculations – not very conducive for editing. If you exported without a full play through, you had to do it twice – once for it to put on its thinking cap and the second to apply that to the mix. Still, the results were pretty good.

Standalone app

Nevertheless, perhaps taking it out of the NLE and into a standalone app was a good idea. It’s a cleaner and more stable approach (NLEs can be fussy about using third party VSTs) – and means it can work for anyone. It’s also better than using an online tool (think mastering sites like Landr for music) as you don’t have to send your files to anyone. And don’t worry, the little robot butler is still present.

Jerre puts it like this on his website:

“The goal was always to add more automatic audio features and presets. Think: de-noising, EQing, creative filters, and who knows what else will be possible… But with every update of NLEs and operating systems the number of “bandaids” needed to keep the “magic” working grew. Sadly it became clear that almost all programming effort went to keeping it running, with no time for adding new stuff.”

The downside is that any time you have to go outside your NLE it adds time to the equation. Thankfully though it is a very quick process, especially once you get used to what settings you want (and they are pretty good on the defaults anyway). The analysis step is much quicker than Alex Audio Butler was – no playthroughs or exports required.

Ease of Use

The first step is to export your audio tracks – separating dialogue (which would include interviews, voiceover, foreground actuality), sound effects (which includes background atmos and any foley or sound design) and music. This can be done simply by solo’ing your tracks and exporting or you can have dedicated submix tracks which can save time in bigger projects. You can either do this in three stems or just add multiple tracks (as long as your pricing tier allows it).

Then open up the End Boost app to bring them in.

And as the manual says “If a file name starts with [v], [m] or [s] End Boost will automatically set the track Source Type to Voice, Music or Sound FX respectively.” Otherwise you can set that manually once you’ve brought them.

After import, End Boost will have your stems – make sure it has correctly identified which each is. It will very quickly run its analysis based on the default settings or the ones you last used & you can hit “Play Preview”. The settings may look a bit complicated, but it’s actually fairly simple & it basically works straight away, you can just tweak it if needed. You can also bring in a video to mix to, which is a good idea as picture affects sound levels (eg if you can see the sea, it feels right to hear it).

These are the main things you need to set (and they all have tooltips over on the right):

Voice

• Set Constant Source if it’s just one voice or Varying Source(s) if multiple
• Set the denoising and compression amounts (the defaults are usually fine)

Music

• Set the target volume (the default IIII is about right, so just lower or raise it if you want to after listening)
• Set the aggressiveness of the auto-ducking (e.g. medium)

Sound FX

• Set the target volume (I find I normally turn down the default a bit, to say II)
• Set the aggressiveness of the auto-ducking (Subtle I think is a good bet)

Mix

• Mastering – basically setting how strong a limiter you want
• Delivery target
  • All-Round is about -17 LUFS which I use for internet delivery
  • EBU R128 is -23 LUFS (Europe’s broadcast spec)
  • Online is about -12 LUFS if you are playing the social media loudness wars.

You’ll notice there’s no ATSC A/85 -24 LUFS/LKFS export for the US market and I wonder if Jerre will add that in a future update. Though I don’t expect people using this tool are doing it for broadcast so I’m not sure it matter too much.

Once you are happy you hit export and there is a very handy drag and drop dialog for you to drag straight back into your NLE to align with your video.

Tests

Now down to some testing. First a simple test of some dialogue and music. Note the audio ducking in the End Boost mix and how the voice comes to the forefront of the mix.

And secondly with some background atmos (I put a little inset video to match it, otherwise it didn’t sound right!)

You can see (hear!) that it works really well, especially with noise reduction done first. The dipping is very well timed, the compression is strong without artefacts and the output levels are consistent.

Who is this for?

As I alluded to at the start, I don’t think this app is trying to compete with the world of Audio Post Production. But the busy editor sending a temp mix during the approvals process might well find it useful. And even more the lower budget content creator who does their mixing in house. Especially if they didn’t know how to achieve these results in their NLE.

I would always encourage budding editors to grow in their audio skills and doing a good temp mix is part of that, so part of me doesn’t want to recommend End Boost for that reason. But on the other hand I think for quite a few people it gives a very good end result that they wouldn’t easily be able achieve themselves. For them I say take advantage of the 7 day trial and give it a spin.