Hi and Low Pass Filters to reach ACX -60dB level

Easy pass. Top three readings and sentence 2/3 down.

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That was one trip through Audiobook Mastering. No Noise Reduction or other processing. You sound exactly like the voice on those education films they used to show us in high school. “The Emperor Penguin lives on the antarctic continent near the south pole.”

Did you actually find something that was causing that russling paper or shifting bedsheets noise? It’s not unusual for people to greatly underestimate how quiet -60dB is.

I’d hate to start recording a book and have ACX reject it for the rustling noise.

Yes, that would not be good. We have had posters who did that. “I read the whole book. How can I fix it so it will pass?”

They allow you to submit a voice test before you plow into Chapter One of your volume. It used to be a minute or two with very particular room noise placements, but it got a lot harder recently. One of our posters copied the ACX requirements and any second now I’m going to find it. They also changed slightly the actual technical requirements, and posted a soundtester, but that isn’t easy, either. They make you plow through the entire submitting questionnaire before you get access to any of the good stuff.

They are a business and they don’t want thousands of people posting every fifteen minutes

You can get close here on the forum and when you get everything stable and reliable, then you post an ACX test.



I did copy the location.


I don’t know that we have a limit to how many times you can ask for Forum Testing. It’s all volunteer, so if we can’t get to it quickly, we get to it later.

10 second stereo and 20 second mono is a forum restriction. If you have longer works, you can post them somewhere else and point to them. We won’t subscribe to anything, so make sure postings are freely and publicly available. Yes, you can submit much longer works as MP3 instead of WAV, but since MP3 adds sound distortion it’s kind of self-defeating.


The rustling has gone, but there is something weird going on.
e.g. there is intermittent choppiness, e.g. “they are in” and immediately after “creator”.

I don’t think the choppiness is bad enough to fail ACX, but it shouldn’t be happening.
It could be digital (skipping), or mechanical within the microphone, (sticking diaphragm).

there is something weird going on.

I don’t hear anything wrong with either word. There is a gasp after the last word—right at the end of the file.


It’s just a momentary glitch …

''they aRe in''.gif

You all requested the file be 10 seconds and unedited, so I chopped it off at 10, which apparently had a breath in it.

Q: Am I correct in thinking I’m relatively good to go on starting to send new auditions to ACX?
OR do you think there is something additional I should address first? RE: the intermittent choppiness, e.g. “they are in” and immediately after “creator”.
I have no clue what I’m looking at in the gif/graph below.

Q2: Just to clarify, I think you’re suggesting that I create a 20-second mono or a longer recording, and run it through Audacity’s ACX Check program noted in the link you provided below, https://forum.audacityteam.org/t/acx-check/55720/1 … correct???

RE: Correcting the rustling, I turned off some secondary speakers and eliminated a fabric covering in the booth. I’m also thinking I might add a sound absorbing blanket to my desktop this weekend.

I very much appreciate your taking time to review and analyze the past tests. It sounds like ACX would not have given any specific feedback, and my auditions would just keep getting summarily rejected. “Sorry, you were not selected, but please audition again for another book.”
So a HUGE thanks to Koz, Trebor and Steve!!!

If you have the option of trying a different mic, that could determine if your current mic is the cause …

If you don’t have another mic try increasing your distance from the mic,
(the pop-filter should be a 4-6 inches from the mic).
Possibly change the mic position to eye-level, above the script, so you won’t be able to blow into it.


Vertical lines on the spectrogram view are a click.
Some words, like “click”, should have a click, but “they are in” shouldn’t.

I know it’s a little hard to follow. We’re having two different conversations. The rainbow thing is the Audacity timeline in Spectrogram view. Pulldown menus on the left of the timeline.

Instead of louder being up and time going left to right, it’s musical pitch rising bottom to top, time left to right, and volume is color. So you can go to a specific time and see (about) which tones are in the sound and how loud they are. Some sound damage reveals itself with this method as being little smooches of color that don’t belong there.

Meanwhile, back at the ranch.

Do you naturally produce stereo (two blue waves) or mono (one blue wave)? ACX recommends mono if possible and you have to stay whichever one you pick for the whole book. We like mono because it’s efficient and easy to edit.

If you do produce a mono track, you can announce a sound test out to 20 seconds using the same basic format posted here.


Do that, including that two seconds of freezing and holding your breath at the beginning. That’s really important for us to check background noises. You can use your own text. You don’t have to announce contented cows.

Scene shifts…

Have you seen the ACX test posting instructions? They’re not the ones on my site; I haven’t corrected that yet. There are new ones.

You have to be able to read well for fifteen minutes and I don’t remember the rest of it. That’s a lot harder than the older specification to read for two minutes or so. You have to be able to keep it together for what could be a short chapter.


There’s a lot condensed into that posting. Grayspires copy/pasted whole segments of the ACX instructions. I think there are actually links back to ACX.

Find text that sounds like you’re narrating a high school instruction film. Another possibility is watch a couple of those fifties promotional film/videos on YouTube.

“Trans World Airlines inaugurated luxury clipper service from New York’s Idlewild field this year…”


Idlewild Field is now Kennedy International Airport (JFK), if you’re keeping count.


I thought the second test sounded like a cat purring while you were talking.
My furry brats are not allowed in the room when I am recording.

The quiet at the start is so intense, it is weird that the noises only show up once you start narrating.


it is weird that the noises only show up once you start narrating.

That’s a significant symptom. That can be Windows Services trying to “clean up” your voice for chat or conferencing. Gating can be one of the tools (ACX doesn’t like that very much).

Dig into Windows settings and make sure all the enhancements are turned off.


Koz and Trebor:
Thank you again for the insights. I’ll start working on the items listed.

I did find two vertical crackles or spikes in an audition I just did, and was able to edit them out. Thanks for the heads up on looking for those. They appeared like single lines in the audition track.

The microphone setup might be an issue. I did find a “card” /label hanging from the mic stand that I hadn’t noticed. It might have been bumping something to cause that noise. Not sure. I’m going to invest in a mic arm that I can bolt to the ceiling and bring down, so there is nothing to bump or jostle.

I’ll start work on the Microsoft to make sure all enhancement settings are off.

I’ll send another 20 sec test after that … and try to isolate the mic stand. I’m guessing you want a RAW .Wav file, right?

RE PURRING … Surrounding conditions include – basement room, quiet neighborhood (most of the time), no furnace on, no cat in the room, windows all blocked with sound deadeners, recording space surrounded by acoustic panels and on roof.

My laptop and monitor are in the space, but there are no computer or monitor fans and it is solid state, so they don’t appear to be making any noise. The light is LED and seems quiet.

It seems quiet to my ear, but… there must be something going on.

ok… on to the Microsoft settings!!

Thanks again for your time and patience.

Rode NT-1A

Did you get the whole doobly-doo set of accessories with the NT-1A?

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That spidery thing on the back of the mic prevents vibrations and building noises from coming up the mic stand and interfering with the performance. The black tennis racket is the pop and blast filter. Most breath noises go straight ahead from your lips or down, so you can do well if you can put the microphone slightly above that.

This is my version of a setup.

In my case, the spidery shock mount is from a different maker than the microphone. Match the sizes and mounts. The mount is rubber bands and it’s not rocket surgery. You can make your own from the hardware store.

It doesn’t make any difference if the microphone is upside down or not, but it does count if the cable is too tight. A tight cable can transmit desk noise to the microphone. Leave a droopy cable.

I will admit to a little Hollywood in that studio shot. It looks grand, but if you think about where your face has to be to speak into the microphone, you would have to be on you knees at the desk. Adjust so you are comfortable and the microphone is in a good place and spacing. If you’re doing a book, you’ll be there for a while.


I did find two vertical crackles or spikes in an audition I just did

Do you know what’s causing them, or are you guessing? Tiny unstable recording problems can drive you nuts in the course of a book wherever they come from.

Nobody wrote you have to record your book on the computer.

That’s a Zoom H1n. That will record a voice track just fine.

Nobody is going to award me any voice production awards, but that clip will pass ACX Technical Standards.

Without problems sound editing takes five times the length of the show. That seems silly until you start to count the actual time and effort. Two shows of time is soaked up listening to the recording to making sure you know where all the errors are, and listening to the whole thing again to make sure you got them all. That leaves three shows of time to do the actual cutting, correcting, patching, filtering, and smoothing. It can go much longer.

Then mastering and then making sure you have the right silence (Room Tone) on both ends of the chapter.

Then on to the next chapter which has to match this one. The first and last book chapters have to match. They check for this stuff.


Gah I wish I was at 3:1
Even after three months of recording, practice, videos, forums, and time-saving macros, and processing techniques, I am still taking so much time to process after I record.
30 pages (Final Length 38:16)
Raw - 60 minutes for the first-pass record (Dog Clicker and some Punch and Roll)
Text Complete (ReDos, Retakes, MisReads Repaired) - 60 minutes (listen and parse, rerecord and splice)
Gasp and Spacing - 90 minutes (Commas, Periods, Sections, Punch-Pasting Room Noise over Gasps, clicking long pauses to uniform lengths.)
Mastering, Encoding - 10 minutes (THANKS KOZ!!!) (Roll Off, RMSNorm, LImit, ACX-Check) PASS!
Relisten for final - 38minutes

So I run about 8:1 (BLEGH!!!)

That’s the comeback for people who want to dash off their audiobook. "How bad could this possibly be?

Not bad at all if you’re a professional announcer in a formal sound studio and you’re not the one that’s cutting it.

There is a video performer I like who will come right out and say, “Don’t call attention to the features of that building because then I’ll have to shoot cut-aways and the edit will take forever.”

Words to live by.



Correct. I got the, as you put it “doobly-doo” NT1-A … Anniversary set, https://forum.audacityteam.org/download/file.php?id=26436

Similar to folks in previous posts, I’m currently spending a frustrating amount of time listening to, relistening to, rerecording, editing, cutting out noise, etc. I’m guessing I’m well above the 5:1 ratio, but getting better each time.

I’d love to eliminate more noise, so I can reduce that phase of the process.

Reality is, my biggest challenge is learning to do it right the first time, and streamline the punch and roll.

Practice, practice.

getting better each time.

Because I haven’t been Suzy Sunshine for at least ten minutes, that’s actually a problem. The first and last chapters of the book have to match.

It’s not unusual for New Users to get to the last chapter as a seasoned professional and go back to the first chapter (which they recorded as a green beginner) and are horrified. And record several chapters again.

There is one New User phenomenon. It’s possible to be too picky. If you can hear things nobody else can, maybe you don’t need to worry about them.

This isn’t the only place to get good tips. ACX has postings and useful instructions and any minute I’m going to find them and post a collection. They changed the free test, for one example.

(Dog Clicker and some Punch and Roll)

We’re been known to recommend something like that. How’s that working for you? The clicker produces a blue spike that easy to see in post.

When was the last time you posted a sound test? Have you ever?

Sometimes we can suggest microphone placement changes and peel off some of the post production corrections, edits, and work. Yes, if you read the wrong words, we can’t help you. You’re stuck there.




You asked: “When was the last time you posted a sound test? Have you ever?”

I’m guessing you’re asking about posting it on the Audacity Forum … If so, the last (second) sound test I did was 1:47 p.m. on March 12, page 1 of this string. But, I’ve made several adjustments… new microphone stand placement, turned off Microsoft enhancements, turned off secondary speakers, etc.

Maybe another test is warranted …?

Also, yes, I’ve been watching several ACX University videos and other audiobook tutorials a day… some of it might be seeping in.

Hope to get to some voice lessons in the near future … presently delayed by the Wuhan Flu.

Meanwhile, several more ACX auditions, but no contracts yet… It’s coming.

several more ACX auditions

Were they failures? What was the failure? Post the ACX response.

Make a forum test. If you’re doing something obvious wrong we may be able to correct it.