Audiobook-Mastering-Macro.txt is a shortcut to automatically apply all three
tools in the ACX Audiobook Mastering Suite.

It guarantees the first two ACX standards, Peak and RMS (Loudness).
The last standard, Noise, is up to you, the microphone, and the environment.

It’s not an effect. It’s a Macro or Batch that runs other effects.
It runs under Audacity 3.0.2 or later.

Tools > Macros > Import > Audiobook-Mastering-Macro.txt > Open > Inspect > Close Window.

Select the chapter, segment, or timeline > Tools > Apply Macro > Audiobook-Mastering-Macro

Audiobook-Mastering-Macro.txt (498 Bytes)

Thank you with all my heart for this!
Marianna :smiley:

It has been a little over 1 year since you taught me how to set up Audacity (HUGE THANKS!!!) and after a couple hundred chapters submitted to ACX, every one comes out about like this, after using your suggested macro:
Peak: -3.5
RMS : -20
Noise Floor -72 to approx -75
My question is that for some reason (I’m sure someone somewhere told me to do it) my very first processing element in the macro is
High Pass Filter set at Frequency hz = 80.00
Roll off (db per octave) = 36db
After that , I use the standard FILTER CURVE, RMS NORMALIZE, LIMITER.
My first question is: any idea where the HIGH PASS FILTER came from? I processed the exact audio with and without it and it seems the same.
Is there any benefit to it or reason I should or should not be using it?
Second, I’ve always used NOISE REDUCTION, if needed, AFTER processing…running the macro. I recently read it should be done BEFORE running the macro. It seems to work better if used BEFORE, but I don’t know if I’ll need it until I run the macro then the ACX CHECK. Thank you for any information you might be willing to share. I’ve been practicing audiobooks constantly, trying to get better and better, and I think one of the main changes I’ve made is playing with microphone placement to get better and better results.
I am open to any and all suggestions…and yes, I have problems with mouth noises, too! BIOTENE dry mouth spray helps a bit for me but I some times have to edit out swallowing, mouth clicks, etc.
Thanks everyone! I love this group. :smiley:

my very first processing element in the macro is

Process nomenclature here. The Macro (or chain, or batch) is a single instruction that calls a collection of tools that naturally go together. That’s what Mastering Macro is.

The Mastering Suite is all the stuff you do manually to get between your raw reading and the submitted sound file. In your case, the Suite would be High Pass Filter > Mastering Macro > Noise Reduction.

In the bad old days, before the Macro, you used to have to execute the three mastering tools individually, one at a time.

That gave you a Suite like this.

High Pass Filter > Filter Curve > Loudness Normalization > Peak Limiter > Noise Reduction.

Let’s zoom into those first two tools. High Pass Filter’s job is to suppress very low pitch sounds, microphone errors, thunder, rumble, and earthquakes. Filter Curve’s job is to suppress very low pitch sounds, microphone errors, thunder, rumble, and earthquakes without, as much as possible, affecting your voice.

So in my opinion you should not be able to tell any difference by leaving out the High Pass Filter. That effect is built into the Macro.

You did do one thing that can cause problems. ACX puts great stress on matching chapters. There is a soft, fuzzy rule that once you settle on a Mastering Suite, you should continue with that exact Suite through the whole book.

Only applying Noise Reduction to some chapters makes me nervous. Are you using Noise Reduction of the Beast (6, 6, 6)? That was chosen because it does effective, gentle reduction that nobody can hear working. If you use other numbers, you can get voice changes between chapters.

I know we’re doing all this after the fact, but those are the concepts.

See if you can tell any sound difference between the High Pass Filter and not. My guess would be to drop it as a hot rock. If there is a difference, the voice without it should be more natural.



Once again, thank you! I knew when I wrote “my 1st process…” that it sounded awkward … now I now why!
I will leave out the HIGH PASS FILTER, but I guess I am still a little confused about the NOISE REDUCTION.
In Audacity, when I go to Tools> Apply Macro, under Palette, there are the macros that I set up. I set up a “macro” chain that I called “ACX.”
When I’m done editing a chapter, I select the chapter, then go to Tools>Apply Macro, and select the one I set up and named “ACX.”
I set up the macro to do three things: Filter Curve, RMS, and Limiter (all set to your recommended parameters).
I realize that what I’m doing and what you describe may be different…?

You wrote:

“The Mastering Suite is all the stuff you do manually to get between your raw reading and the submitted sound file. In your case, the Suite would be High Pass Filter > Mastering Macro > Noise Reduction.”

But in my case it seems my Mastering Suite is applying my Mastering Macro (which I named “ACX”) and then NOISE REDUCTION. I say (ask) this because when I apply my macro, it automatically runs FILTER CURVE, RMS and LIMITER. And before I removed it (at your suggestion) It used to run the HIGH PASS FILTER, then FILTER CURVE, then RMS, then LIMITER.

Anyway It always passes ACX CHECK.
I understand NOISE REDUCTION should be used at 6,6,6 (or maybe 9,6,6 which I recently read on this site) and if I’m doing a book I will always use the same settings.

My main question is, should I be applying NOISE REDUCTION before or after I run the “ACX” macro (which applies the FILTER CURVE, RMS and LIMITER) ?
I have always applied NOISE RDUCTION at 6,6,6 AFTER I run the FILTER CURVE, RMS, LIMITER. I read somewhere that you can (or maybe even should) apply NOISE REDUCTION BEFORE the FILTER CURVE, RMS, LIMITER.
I’ve tried both ways and NOISE REDUCTION seems to work better BEFORE the macro. So I would love to know which way is correct. Thank you.

Thanks again for your thoughtful, helpful, very informative and speedy responses!
Since I applied your technique, I have never had a chapter rejected from ACX, but I want to learn all I can about the technical side of producing audiobooks to get the best sound possible.

PS I wish there were more people like you in the world, who are so willing to share their knowledge and help others!

Are you applying Noise Reduction for a reason? What does ACX Check say if you just announce a test normally, apply the macro, and don’t put Noise Reduction anywhere?

Another possibility is announce a forum test, don’t do anything to it, and post it here.


I’ve given that question some thought and the answer is that although my audio always passes ACX CHECK I use NOISE REDUCTION to bring the noise floor from around -68 or -70 to something more like -74. To be honest, I’m not certain that’s the best strategy… I was just using it at 6,6,6 (and I made up 4,4,4) to try to get the best audio possible… I have this kind of obsession about the noise floor and I like it as low as I can get it, but if you say leave it at -68 or -70 and stop using NOISE REDUCTION then I will… Because I’ve only been at this for a year or so and I’m just trying my best with what little I know. Thanks.

The specification for noise is -60dB which, in English, means the background noise has to be a thousand times quieter than your voice. If all of your noise is microphone hiss (gentle rain in the trees), then that’s all you need.

The rules change if your noise is more annoying than that. There is a microphone error that produces noises like a child screaming on a jet. There are special techniques for those problems.

The system rings alarm bells if you submit noise at -59dB (very slightly too loud), I picked a real-world standard of -65dB. That way you can mess up a little and still make it past. That’s also the reason for the -3.5dB mastering standard for peaks. The real standard is -3dB, but that doesn’t leave any room for errors. This isn’t about you. The conversion to MP3 for submission creates errors.

from around -68 or -70 to something more like -74.

This is where you look in a mirror. If you are an industrial producer cranking out multiple good quality audiobooks every month, then -68dB is good to go and abbreviating the production pathway is indicated.

Keep the production pathway as short and simple as possible. This also guards against skipping a step by accident (not that that’s ever happened to me).

If you are an obsessive shooting for the best possible production quality, then apply Noise Reduction of the Beast (6, 6, 6) to every chapter just before Mastering.

and I made up 4,4,4

That’s dangerous. Only the first number controls the depth of reduction. The other two control quality, speed, and sound damage. Factory default is 12, 6, 3.

No, it’s not possible to reliably include Noise Reduction in a Macro. People would kill to be able to do that.



At the risk of sounding repetitive, I can’t help but to say the first thing that comes to mind: THANK YOU! I have no idea where else I could get such reliable, professional information. I WISH I was booked up with producing audiobooks, but the truth is, the last one I did (weeks and weeks of day and night work for a fairly well known author) turned out to be a scam… I had run into it early on and thought I knew all the red flags on ACX, but the scammers have gotten more sophisticated. I had a complete manuscript, blah blah :blush: but I ended up chatting with the REAL author and her Producer so at least I made some contacts, (even though I can’t use audio samples of the book on my profile, which sucks because it was my best work yet) Anyway, the point is, I have more free time than I want, so if there is ever anything I can do for you, please don’t hesitate to ask. I, along with a lot of other people on this forum I’m sure, feel lucky to “know” you, and even though my audiobook career is getting off to an even slower start than I expected, it wouldn’t have started at all without your help.

One last thing: I’m still not sure whether it matters if I apply the NOISE REDUCTION before or after the mastering. …Does it matter? Thanks…again…for everything!

PS Most of my background noise is just white noise, gentle and not too distracting (except to me, lol) along with the occasional mouth noise and clicks we all seem to have to work on. I’m listening to an audiobook now from Audible where at high volume I can notice the screeching (baby crying type noise?) in the background…almost sounds like feedback…not distracting though and it’s not a noise I have ever noticed in my recordings. Its like this up and down high pitched sound in the far distance of the recording noticeable in the quietest parts and I never noticed it before in any other book. Since producing audiobooks though, I listen much more intently than I ever used to. :slight_smile:


Since producing audiobooks though, I listen much more intently than I ever used to.

Thus ruining a perfectly good entertainment medium.

You go to the movies to be transported to a different time and place, not to criticize the director’s production style. There is a Youtube explainer series I can’t watch because the performer sounds like they recorded in a bathroom. I can’t get past that. It ruins the show for me—but they have a following.

Its like this up and down high pitched sound in the far distance of the recording

I bet I know why it’s there. Changing or moving background sounds are permanent. There’s no filter or effect to remove them. It’s a cousin to the inability to split a mixed performance back down into individual instruments, voices, or sounds. It’s why studios exist, to isolate you from all other sounds.

If the noise is 60dB quieter than the voice, then it’s “legal.” The idea is to set performance volume for pleasant listening and then just listen. Cranking the volume all the way up during the Room Tone segments doesn’t count.


turned out to be a scam… I had a complete manuscript, blah blah, but I ended up chatting with the REAL author and her Producer so at least I made some contacts

Someone commissioned you to read their manuscript pretending to be a different author?

I ended up chatting with the REAL author

How? Real Life? Zoom? That’s probably a story, right?

I can think of one way around the scam. ACX demands that your audiobook be already for sale in either paper or eBook on Amazon. This manuscript wouldn’t qualify.


It was someone who commissioned me to read the manuscript pretending to be the REAL author. They sent the manuscript with cover art, etc. After ACX spotted and flagged it as a scam, I contacted the real author through Facebook and she messaged me through Messenger, then had her Producer get in touch with me. He said he will keep me in mind for auditions (put me on a list of narrators) because he is always booked and has extra work. I should have contacted her before I accepted the job to verify her identity…lesson learned.
The book was and is on Amazon with hundreds of reviews. I don’t know of any way I could have known it was a scam except to have made sure the RH contacted me through an email I could definitively associate with them. ACX apologized and said next time I could call them to verify the authenticity of the RH, but other narrators in a FB Narrators group questioned if they could really do that, and that if they could, EVERY narrator should call for EVERY book. ACX is slow to spot and overwhelmed with scams. In fact, I asked ACX when I spoke to them why it took them so long to spot the scam and they said (basically) that it was so common these days they were constantly working on verifying RH bona fides.
The scams are getting more sophisticated and this has happened to many other narrators, so much so that one person in a group said getting scammed was like a rite of passage on ACX! Other members said that just seeing such an established author on ACX asking to have an audiobook produced for Royalty Share was a red flag, and they were correct. This author sends her books to her producer and he takes care of the rest. She jokingly told me her books “magically appear in audiobook format.” She doesn’t deal with ACX, he does. Everyone was helpful and supportive though.
Looking on the positive side, I made contact with the real RH… a very nice, very talented and very successful author, as well as her producer who I may be able to get more work from…yay for networking, lol!

made sure the RH contacted me

It’s a shaky idea to use abbreviations on the forum. Who is RH?

FB Narrators group

Face Book Narrator’s Group.

they were constantly working on verifying RH bona fides.

ACX instantly went underwater when the virus hit and everybody on earth wanted to submit for publication (and half the staff called in sick). That’s for valid writer/readers. I didn’t think of what would happen if scammers got into the act.

just seeing such an established author on ACX asking to have an audiobook produced for Royalty Share was a red flag

What does that mean?

There is a standing joke between some cross-word buffs that the easiest way to leave us in the dust is dig into current popular apps.

4-Down. “Treasure Chest from the Fourth Facebook Level.”



RH = Right’s Holder (Author, Publisher, etc)
This author is a USA Today and New York Times best selling author…she has used mostly the same narrators for her books. She isn’t as big as James Patterson, but she isn’t the type of newer or Indie (Independent) author one usually sees on ACX. It also means that if someone as big as her picked someone as new as me (4 books on Audible) …well, that’s probably unusual as well. She pays 2 narrators a substantial amount to produce her work (easy to research) and then sells a lot of books, so why would she be advertising for Royalty Share with a newbie? I thought, “Wow, I guess she liked my voice!” I should have ben asking, “Hmmm…why me and why Royalty Share?”
Yes, the pandemic has turned ACX into a vipers nest of scammers. ACX (I hope) are doing their best, and of course I want them to succeed but a lot of people won’t even deal with them because of the scamming pitfalls. It’s generally agreed on Face Book narration groups that narrators/producers need to do their best to verify the identity of every Rights Holder who posts an audition on ACX, and try not to get fooled like I did. One member even wrote that their book was auditioned for, accepted, and completed on ACX, then went up for sale on Audible, etc before they realized that the supposed Rights Holder was not who they claimed to be! When the REAL author (RH) found out, legal action ensued!

why would she be advertising for Royalty Share with a newbie?

That part. What’s that?


I wrote a couple long paragraphs in response to that question and then lost them. I don’t know if my finger accidentally hit submit or not. Let’s assume I didn’t and I’ll answer the question here:

There’s two main ways to get paid: Royalty Share which is 20% of the audiobook sales for the next 7 years or PFH which stands for Per Finished Hour, which is a one-time payment for the finished audiobook.

I know this author usually uses experienced narrators that charge high PFH prices for their books. When I asked, “why would she pay a newbie like me royalty share?”,
we can safely assume she sells a lot of audiobooks. Royalty Share would give me 20% of all her audiobook sales for the next 7 years. She would probably be better off paying a one-time Per Finished Hour fee like I assume she’s been doing.

Royalty Share is usually for an author that wants an audiobook produced for no money down and is willing to part with 20% of its sales for the next 7 years. For example, my first 4 books only sold 100 or so copies total. I’ll get royalty share for 7 years but it still won’t be much and it didn’t cost the author anything. But hey, you have to start somewhere… and I was fine with that.
I’m a MUCH better narrator than a was a year or even a few months ago, but I know I’m not as good as the narrators that this author has been using, so maybe I should have written, “Why would a successful author like her be interested in me?”
I fooled myself into thinking I was actually as good as the narrators she’s been using… I’m not. 4 books is still brand new and her narrators have done hundreds. Getting picked up by an author like that was (in fact) too good to be true!
A narrator more humble than me might have thought, RED FLAG!

ON A DIFFERENT BUT RELATED TOPIC: I’ve been hearing since I started that you should position the microphone about pinky to thumb (hang loose) distance away from your mouth. Other people say 12 to 18 inches.
I recently saw a drawing (I believe it was yours) where the person had the microphone positioned in front of them and off to the side. It got me to reexamine my microphone position which was more than 18 inches away, and now that I’ve moved it closer to my mouth, my audio sounds MUCH better. So much so that I’m in the process of making all new samples for ACX, and I’ll be auditioning soon with renewed knowledge and confidence.
So once again… THANK YOU!

Other people say 12 to 18 inches.

That’s good if you’re performing in front of a mind-meltingly expensive microphone, or an old, very rare microphone, with a sound engineer in a soundproof studio at Glen Glenn sound.

Home performers need not apply. Through some marketing decisions, home systems are almost always quiet. Microphones have restrained volume and interfaces have less boost than they need. I called Shure and complained about their X2U interface.

“I would give anything,” I said, “for just 10dB more volume boost.” “Sorry,” they said. “That’s the way it is.”

I put it in the Garage.

It got so bad, (how bad did it get?) It got so bad, you had to yell to get any good recording volume (never blow into a microphone), and Microsoft started including “Microhone Boost” settings in their sound control panels. That created its own set of problems. That boosted everything including the natural microphone noise (shshshshshshshshsh), air conditioning noise, and the Metrobus in front of the house.

You get closer to the microphone to try and override the noises and start P-Popping and recording mouth noises. That’s where the Hawaiian Shaka came from.

That turns into a Power Fist if you’re using a pop and blast filter.

Nobody wins here.

That brings us to Oblique Positioning (B).

Since mouth noises tend to go straight in front of your face and downward, don’t put the microphone there. Place it off to one side (roughly opposite your cheek) and level. You can get it a lot closer (and louder) without mouth noises.

Given this is not going to sound anything like Glen Glenn sound, proximity effect, etc, but it will get you through a voice-over or audiobook. Just don’t move around a lot while you perform. Real-time monitoring on good headphones is demanded with this technique.

That’s David Greene and his Sony MDR-7506 sealed headphones. One caution. Those headphones will show you errors before anybody else can hear them. That’s why Hollywood uses them. They’re not designed to settle in and watch a movie.


… Hawaiian Shaka came from.

I guess it would be “Hang Loosely,” right? It’s the adverbial form?

Someone will correct me.


I love when your responses include diagrams, pictures, etc! It was that same diagram that inspired me to change my microphone position!

I’m using an AT2020 condenser microphone with a Focusrite Scarlet Solo interface with Samson SR990
headphones. The gain is positioned at around 2:00 o’clock.
I don’t know why it took me so long to get closer to the microphone, and I also use the oblique positioning. As I mentioned earlier it’s improved my audio quality exponentially. When I was farther away from the microphone and it passed ACX check every time I thought I was doing everything right, but moving closer to the microphone was a game changer.

I would be thrilled to record at a place like Glen Glenn, or any other professional studio for that matter!
For now, I’ll continue reading, chatting, learning and experimenting while I practice the art of narration.
I really enjoy the whole process, editing and mastering included.

As always, I’m grateful to you and everyone else on this site. I’m sure I wish I knew as much as you’ve forgotten about audio engineering. A lot of people with your knowledge wouldn’t bother with newbies like me so I appreciate your seemingly unlimited patience and support! :+1:t2:

In French locale I had to modify “Limiter” by “Limiteur”.
Audacity 3.1.3 ; Debian 11.2 (Bullseye) ; Xfce 4.16