Advice on Chris's Dynamic Compression: use INSTEAD of RMS Normalize? When to do the De-Noise?

Special Interest Groups Audiobook Production
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a humble actor with a marketable voice.

I wondered. I spent a long time in Washington, DC and when Dulles airport went on line, they had the Tannoy/PA System announcements in your voice. “American Airlines flight 45 now boarding, gate 5.” It was glorious while it lasted.

As I get closer to actual experience with DeEsser, I found I can watch the filter working. DeEsser, when launched and set, produces a progress panel on the screen and if you can watch the blue waves in your timeline, tiny portions of each blue word-blob vanish or decrease in volume.

I worried that such a waveform change could affect ACX conformance, but it didn’t seem to. DeEsser certainly helps with the “ice pick in the ear” sound of harsh sibilance. This is such a wide-spread problem I’m learning how to spell “sibilance” without looking it up each time.

I found the best way to test for effectiveness is not so much flipping back and forth between two different timelines, but use one line and only correct half. Critically listen at the switch point and it’s possible to more clearly hear the cutting edge of each S sound vanish.

You might try the correction on a freshly mastered clip and overdo it with the -30dB setting just to hear the “cartoon” effect.

every presenter under forty seems to lisp these days; but that’s actually a trick of the microphones, eh?

It’s a bad trick. One producer claimed on the forum he DeEsses everybody and produces desirable results almost always. It’s visible. You can Analyze > Plot Spectrum and see a little “haystack” caused by the boosting of certain vocal tones. This led to analyzing the tones and writing a custom Effect > Equalization setting to suppress it. That’s effective, too, but it has to be done for each presenter/microphone. DeEsser has analysis and detection built-in.


What did you decide for theater corrections: breaths, tongue-ticking, and wet mouth noises? My Opinion is ignore the breathing unless you’re clinically asthmatic like one reader and concentrate on ticks and clicks.

And there our story turns to christianw and his vimeo presentation. I believe he addresses those corrections.

Making an Audiobook with Audacity

Note he uses other Mastering processes. We both get there using very different techniques. Theater corrections are addressed after that.

Koz

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I’m going to vanish in about two hours. If you have any testing you want, you should hit it before then, or wait until tomorrow.

Koz

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Oops. Sorry. Just spotted that.

Thanks again. It should be a small matter, then, to de-ess the chapters I have already edited.

I am into work for an early call this morning.

I realised that, on a Sunday, there is not so much background traffic - so decided best to leave it until this afternoon or tomorrow morning (my Tuesday), when there will be the usual heavy trucks through the day.

I’m thinking perhaps I should send a 20sec sample of one of my finished chapters — to check that it’s not going to sound too processed for ACX.

All the best,


E

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If your problem is low pitch rumble and walls shaking, most of that is going to vanish in the First Step : Equalization. That’s one of its jobs. If you can actually hear clashing of gears (does anybody clash gears any more?) then yes, that may be audible. Honking is pretty obvious.

I don’t remember mentioning I have a bad pavement patch in front of the house. If the Metrobus hits it just right, I get a 1.8 Richter in the front room, but I’ve never heard it in any recording. Fair warning if the rumble and vibration are enough to cause stuff in the house to vibrate, then the stuff may make it into the show.

There’s a Hollywood joke about the wine glass. You can’t photograph an earthquake, so you are required to show wine in a glass making rings. If it’s bad enough, the glass falls over.

Yes, post a finished clip.

Koz

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I’m thinking perhaps I should send a 20sec sample of one of my finished chapters — to check that it’s not going to sound too processed for ACX.

It will be our opinion, but yes. We’re on the edge of our seats.

Koz

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Great advice. Thank you very much.

Yes, I live in a port town at present and there are trucks rumbling by all the time. The lorry gears do whine as they accelerate - and, when they trundle over a certain section of bridge there can be bangs and thumps. Though that wine glass would not register a ripple. My friend, who is a video editor, went over a couple of chapters for me and said I was worrying too much about what I overheard through the mic monitor — that the truck sounds were barely audible to him.

Unfortunately, I just learned that Osaka is on a three day bank holiday — so I won’t get normal daytime traffic until Thursday.

Instead, I will attach two samples, if that’s OK: the raw recording; and one I have just started to process (with LF Rolloff, Noise Gate, RMS Normalize to -23, and some de-clicking* — mostly only between spoken bits*). I experimented with making the LF Rolloff a little less steep, so as to preserve more lower harmonics.

I have not limited yet. I was wondering whether to use what had become my usual (Chris’s Compress Dynamics) or switch to your formula (Effect > Limiter: Soft Limit, 0, 0, -3.5dB, 10, No > OK). It also occurred to me that it might be OK just to run the limiter once at the end, after the theatrical edit?

[*De-clicking. I am restraining my usual urge carefully to remove every last pop, smack and mic “nit”, because I’d love an opinion as to what ACX finds passable. My edits take four times too long as I obsessively clean the spoken audio — eg., applying declicker only between plosives so as not to muffle 't’s and 'd’s. I need to streamline my approach, or hand the audio master to someone else]
Screen Shot 2018-09-18 at 06.00.33.png
Screen Shot 2018-09-18 at 05.45.46.png

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Don’t change Low Rolloff for Speech point by point. that way lies insanity. Instead, change the “Length” slider to the left. From the original recipe, the length slider should be about 5000 for mastering. The filter will be less strict with a lower number. And yes, you would one of the victims of that filter affecting men’s announcing voices. If you have been using that filter with a 7177 length as in that illustration, just returning it to the recommended 5000 or slightly less might be enough.

Failing to use a filter is not recommended because of digital microphone oddities.

Here’s how to find out.

Select a goodly chunk of Room Tone (see how handy Room Tone is?) > Analyze > Plot Spectrum.

You can grab one corner of the display and make it wider to reveal more information. This is what the bottom of mine looks like.



Screen Shot 2018-09-17 at 15.34.23.png

Those are the settings. It will tell you if you didn’t select enough Room Tone.


I found an “evil” clip to use as a sample.

The display is low pitch sound on the left, high on the right. Louder is up. It looks at the whole clip you selected at once. It can’t tell time. In a perfectly recorded analog microphone system, there would be little or no activity to the left of 20Hz. Digital systems, in contrast have no real world restrictions.



Screen Shot 2018-09-17 at 15.39.57.png

Here’s a bad one. Note that there’s activity at 2Hz (reading on the bottom). Not only is that not audible, it’s not even sound. That’s an earthquake.

This is Plot Spectrum after Low Rolloff.

Screen Shot 2018-09-17 at 15.46.56.png
It starts the affect at 100Hz and suppresses everything below that. That number was picked as a trade-off between damaging your voice and getting of rid as much rumble as possible. Everybody knows what the 100Hz filter does. It actually appears as a switch on the sides of some microphones.

Instead of Effect > Equalizer, you might try a custom setting of one of the other tools.

Try Effect > High Pass Filter, 40Hz, 24dB.


Screen Shot 2018-09-17 at 15.55.35.png
Listen to what it did. Write it down if you like it and use it as the first step instead of Low Rolloff.

~~

If you’re happy with the Chris process you should stick with it. Limiter directly affects passing ACX Peak. If you pass that now, you don’t need Limiter.

You should try and avoid mixing and matching suites. Mastering 4 is a series of tools that produce predictable affects and then clean up after each other. If you use them out of order…

I obsessively clean the spoken audio

Yup. That’s a problem. It’s not a good idea to crank up your headset volume to “dive for noise.” You will be doing that one book for the rest of your life.

There is a technique to submit a test to ACX

Koz

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This is terrific. Thank you.

It’s now nearly nine am here, and I have noticed that many truckers are not observing the bank holiday — so I did take a couple of samples of traffic at it’s worst.

Nb. I would usually close my blackout curtains — and my air vents — to keep the worst of it at bay.
To show the contrast, this is morning traffic with them all open:

And here is the same time of day with everything sealed:

This is an analysis of the heavy traffic room tone:
Screen Shot 2018-09-18 at 08.49.22.png
So, if I understand correctly, there is really no sound beneath 35Hz - and that bactrian camel hump is just an artefact of the mic?
Well worth removing.

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to keep the worst of it at bay.

You could record that way, but I probably wouldn’t. Attached is the last clip with Mastering 4, Noise Reduction and DeEssing.


Screen Shot 2018-09-17 at 20.02.49.png
Note the noise is -62.5dB. That means even with noise reduction, you’re still within spittin’ distance of failing noise (-60dB). The next more powerful noise reduction is the last one before you start to experience voice distortion.

So now several unpleasant options present themselves. ACX puts great stock in matching chapters. So:

– Arrange to record with roughly the same traffic sound through a whole book.

– Record everything at night.

– Mix and Match times with stiffer Noise Reduction, hope nobody notices and be sure to apply the same corrections to everything whether the chapter needs it or not.

– Mess with the other technique and hope Noise Gate can pull you through. Remember, noise accommodation is very different between the two techniques. In Chris’s Technique, it must go at the front.

– Add physical noise suppression. That would be my first stop. One of the other posters who hasn’t checked back yet is trying a “portable studio” that shows promise.

I need to drop out and search for the posting.

Koz

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Got it. I was afraid I hadn’t saved the link.

https://voiceoveressentials.com/product/porta-booth-plus

Or its big brother

https://voiceoveressentials.com/product/porta-booth-pro

Note in both of these it’s not desirable to back yourself up against a plain, hard wall, or if you have no choice, cover the wall with what is turning out to be the traditional furniture moving blanket. The most sensitive part of the microphone is pointed at your face and parts of the wall behind you.

And in all of these solutions, give a thought to how you’re going to hold everything up and where you’re going to put your script.

If you go that route, post back how it went.

Koz

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Let us know how using Effect > High Pass Filter goes.

Koz

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Sorry to have been absent for five days.

Had a busy couple of days at work.

Thank you. I will see if I can spot the difference between LF Rolloff and High Pass (though I’m guessing that Rolloff might be more flexible).

I will also look into the best de-Essing.

I promised you a sample of actual book.

Here are two from the opening para:


The first was RMS Normalized, dynamically compressed and then limited; the second was the original raw recording.
I have not tried de-essing yet.

The second two were at random from further in.


Same processing for the first; the second raw.

Just as a matter of interest do these latter two samples even sound as though they would need de-essing?

And generally, after that processing, does the voice remain natural enough to pass the ACX human test?

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I will see if I can spot the difference between LF Rolloff and High Pass (though I’m guessing that Rolloff might be more flexible).

If you have a low pitched announcing voice, you will notice a much fuller and firmer voice with High Pass. The down side is High Pass may allow more home microphone errors to go through.

Just as a matter of interest do these latter two samples even sound as though they would need de-essing?

Doesn’t matter. You can’t mix and match corrections through the audiobook, If you use a correction once, in general you need to do the same thing the whole way. Chapter matching is a big deal with ACX. That’s also why one of the goals is to pare the number of effects to a minimum. Don’t throw extra corrections in there because you feel like it. You will need to do that !@#$% correction for the whole book.

One of the good things about DeEsser (as far as I can tell) is it makes the decisions for you. If it’s not needed, it just doesn’t do very much, and you can’t tell ahead of time.

The first was RMS Normalized, dynamically compressed and then limited; the second was the original raw recording.

I so wouldn’t do that. RMS Normalize may intentionally create sound damage that Limiter cleans up. If you stick a compressor in the middle, Compressor may try to carefully preserve the distortion—or make its own. That and putting a compressor anywhere means some tools like Noise Reduction stop working right.

I’m listening to the works.

Koz

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You got supersonically lucky. Your microphone system appears to be very well behaved and you don’t need the extra protection of Low Rolloff. This is from the unprocessed clip.


Screen Shot 2018-09-22 at 18.26.29.png

So this is High Pass: 40Hz, 24dB (instead of Low Rolloff)

Effect > RMS Normalize: Target RMS Level -20dB > OK.

Effect > Limiter: Soft Limit, 0, 0, -3.5dB, 10, No > OK.

Followed by DeEssing at its default settings.

I don’t see any need for Noise Reduction. The clip passes after those corrections, further, I bet it sounds exactly like you, except a little louder.

I think the background noise is actually better than that. ACX Check couldn’t find a continuous, clean 3/4 second of background sound to measure.

Koz

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Here. Watch. I’ll do it again. Same settings.

There is one difference to this one, I added gentle Noise Reduction of the Beast (6, 6, 6) at the very end of the process. Technically, it’s not needed. You pass without it, but it sounds just a bit better with it.

Drag-select a segment of clean room tone. Effect > Noise Reduction > Profile.
Select the whole clip by clicking just right of the up arrow (on the left) > Effect > Noise Reduction: 6, 6, 6 > OK

If you set your playback voice volume for comfort and then play the whole clip, the noise at each end for all practical purposes vanishes. All that and you still sound like you.


Screen Shot 2018-09-22 at 18.53.54.png
I really hate sleeping in my armour. It gives me such a crick in my back.

Koz

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If someone posts you need to go in and remove all your breaths, I don’t agree. I think that’s a perfect dramatic reading just as it is and I think ACX will agree.

Koz

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Thanks once again, Koz, for all your help.

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<<Jury’s out on Noise Gate. Typically you can hear it working and ACX hates that. People claim success and I should investigate.>>

I’m using noise gate to reduce breath sounds
reduction -22 dB
threshold 15.8 dB
attack 120ms (any faster than that reduces -ed and -ing and plurals on the ends of words)
release 707 ms

That still leaves a sound, but not a distracting one. Some of the loud ones need to be reduced too. But that’s an easy one to do during proofing–select and amplify -15.

Of course it will depend on the volume of the original recording, and mine are at about peak levels.

I use Noise Reduction only when the washer-dryer in the next room are being recorded along with my narration.

So my success with Noise Gate is GREAT. I’ll be interested to see what anyone else experiences with it.

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washer-dryer in the next room are being recorded along with my narration.

Since Noise Reduction in any setting but the most gentle affects the voice, I should avoid recording when they’re running.

I’ll be interested to see what anyone else experiences with it.

I’ll be interested in what ACX thinks of a submitted sample.

Koz