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ACX Mastering
Posted: Fri Dec 02, 2016 4:43 am
by lwitek
Hello my name is Laura and I recorded the first chapter of an audio book that has failed the ACX check. The ACX QA Team suggested, "recommend increasing gain on microphone..." and this has helped me to pass the plugin ACX Check with a number of test files.
I would like to use the "Audacity Effect" tools (Amplify, Compressor, Equalization, Normalize, etc...) to see if I can bring my first chapter into ACX compliance. I have reviewed a number of related topics posted on this forum regarding ACX Check and used some of suggestions to no avail.
My setup is as follows:
-Microphone Shure SM7B Dynamic Vocal Mic w/ Mic Boom Stand, Pop Filter
-Zoom R16 - Recorder/ Interface/ Controller
-Windows 10
-Audacity 2.1.2
-with Plugin ACX Check
-with Plugin Wave Stats
I have attached a sample wave file and a pic of "ACX Check output(s)"

- ACX Check Output.png (39.4 KiB) Viewed 2385 times
and I would greatly appreciate any suggestions on how I might be able to "Master" this recording to meet ACX guidelines if at all possible.
Thank you in advance.
Sincerely,
Laura
Re: ACX Mastering
Posted: Fri Dec 02, 2016 4:58 am
by kozikowski
You should be working in Mono rather than struggling with two-channel stereo. Everything is easier or more efficient.
I got it to pass with relatively simple corrections. I made it louder and added very gentle noise reduction.
ACX is very particular about having your chapters match. If you added a ton of effects to the succeeding chapters, 1 and the others are not going to match.
I'll post with step by step.
Koz
Re: ACX Mastering
Posted: Fri Dec 02, 2016 5:17 am
by kozikowski
Normalize
-- Select the whole clip or show by clicking just above MUTE.
-- Effect > Normalize: [X]Remove DC, [X]Normalize to -3.5 > OK
Noise Reduction
-- Drag-select Room Tone, silence or the flat area between spoken phrases.
-- Effect > Noise Reduction: Profile
-- Select the whole clip or show by clicking just above MUTE.
-- Effect > Noise Reduction: Settings 6, 6, 6 > OK
Don't let "Normalize" scare you. That's Audacity Speak for turn the volume up. It's a sister to Amplify. They differ in how you tell them to change the volume.
I used the silence right after "And her commission" for the Noise Reduction Profile. I believe ACX makes you include a silent room tone segment and you should use that. It's a grand mistake to "make silence" with the Audacity tools rather than using the actual room background noises. That will stop Noise Reduction from working.
By the way, making "fake" silence also gives you bogus ACX-Check noise readings. There's no such thing as -206dB Noise. A normal WAV export from Audacity runs out of steam at -96dB and some of the processes prevent it from going even that low. I expect natural noises to come in at -60dB to -70dB which is why the ACX specifications are -60dB. I can hit that with a very good microphone, a dead-quiet room and no Noise Reduction.
Busted!
You can see from my ACX Check readings, -60.3dB, the actual, real-world noise just barely passes. If all Chapter 1 passes, we're done. If it juuuuust fails noise, UNDO the noise tool and re-apply it with 8, 6, 6 instead of 6, 6, 6. That's a slightly stiffer noise reduction and slightly higher chance of voice distortion
Koz
Re: ACX Mastering
Posted: Fri Dec 02, 2016 5:22 am
by kozikowski
The mono ACX-Check you posted was for the whole chapter?
Do you have Chapter 1 posted somewhere we can see the WAV version? I think that's the only way I can give you whole chapter correction.
Koz
Re: ACX Mastering
Posted: Fri Dec 02, 2016 6:19 am
by lwitek
Hi Koz,
Thank you so much for your quick reply. Wow...
I just tried to upload the whole chapter twice. I believe I was kicked out of the post each time; possibly for too large a file. I do not show it completed on the site. If that is the case, do you have a suggestion and how I can get it to you. It is 106 MB.
Thank you again, Laura
Re: ACX Mastering
Posted: Fri Dec 02, 2016 2:43 pm
by Gale Andrews
Please note I changed your username to lwitek. It is a bad idea to expose your e-mail address in your username because nasty bots that harvest addresses for spammers will see your address then you will receive spam. Please log in with your new username.
lwitek wrote:I just tried to upload the whole chapter twice. I believe I was kicked out of the post each time; possibly for too large a file. I do not show it completed on the site. If that is the case, do you have a suggestion and how I can get it to you. It is 106 MB.
The file size upload limit for Audacity Forum is 2 MB.
You can upload to an online file sharing service then give us the download link
https://www.dropbox.com/
http://www.dropsend.com/
http://www.mailbigfile.com/
http://www.sendspace.com
Gale
Re: ACX Mastering
Posted: Fri Dec 02, 2016 4:54 pm
by lwitek
Hello Gale,
Thank you for all your help.
I have uploaded Chapter 1 as requested as well as Chapter 2 which I just finished editing early this morning. These recordings were both recorded at the same old levels. These can be found here:
https://spaces.hightail.com/space/yuQ0S
Please note the following:
1) I was able to edited the wav file you edited and I was able to get your results.

2) I was unable to use the same instructions to edit Chapter 1 and pass ACX Check, as you thought I probably would.
3) Regarding your comment, "It's a grand mistake to "make silence" with the Audacity tools rather than using the actual room background noises. That will stop Noise Reduction from working....." To the best of my knowledge I did not do this. I did copy and paste room silence to various places. Could this be the cause of what you observed?
4) In your opinion, should I go back to the old preamp setting (I raise mic level and output, small amounts) for the rest of the chapters to maintain continuity with how I recorded Chapters 1 & 2?
Thank you so much.
Sincerely,
Laura
Re: ACX Mastering
Posted: Sun Dec 04, 2016 3:25 am
by kozikowski
It's not unusual for a performer to wander a little in expression and volume over a 20 minute chapter.
I corrected your chapter...and then sent it to Diane instead of you.
Laura, meet Diane.
http://forum.audacityteam.org/viewtopic ... 00#p316621
I'll be straightening this out now.
Koz
Re: ACX Mastering
Posted: Sun Dec 04, 2016 3:33 am
by kozikowski
...
I got a correction to work on chapter 1. I need to pause and collect how I did it.
...
I have an odd complaint. Starting from the download (perfectly lovely, by the way), tell me who you are.
Your posting scrolled from the active help forum window, so I have to go looking for you. There's no identifying information in the download page past what I can glean by actually playing the work and identifying the characters. Is "DB" the name of the show?
The elves juggle many multiple postings, complaints and suggestions and I for one can't remember individual posts. I juggle two browsers, so there's no return link to the forum.
Attach for Chapter 1.

- Screen Shot 2016-12-03 at 16.37.00.png (40.81 KiB) Viewed 2323 times
You got expressive and theatrical at 9:50 or so and the blue waves poked up and threw off the overall average volume. "Rob!! You called him Rob!!" That's OK. You didn't break anything.
Audio Compressor
-- Select the whole clip or show by clicking just above MUTE.
-- Effect > Normalize: [X]Remove DC, [X]Normalize to -3.5 > OK
-- Effect > Compressor: Thresh -20, Floor -40, Ratio 2:1, Attack 0.2, Release 1.0, > OK
-- Effect > Normalize: [X]Remove DC, [X]Normalize to -3.5 > OK
The compressor removed the expressive peaks, pushed up the overall volume enough to pass RMS (Loudness). The settings are gentle and graceful, so I expect any damage to be minimal if you can even find any.
Attached: Before and After blue waves. After is slightly louder and has more "beef" to it. That's not a bad explanation for RMS. Electrical RMS is a measurement of energy, horsepower or density of a wave. It tracks very well to overall show loudness which is why it's used.
Koz
Re: ACX Mastering
Posted: Sun Dec 04, 2016 4:43 am
by lwitek
Hi Koz,
First, I am so sorry regarding the lack of "identifying info" in the "dropbox" link and the two files (Chapter 1 & 2). I am new to "dropbox" and did the bare minimum for lack of understanding the software and your needs. I will do my best to completely identify items in the future as requested. DB is the initials of the title of a book(s) (first of three I am told) I am narrating. Although I have years of announcing and commercial work experience, I am new to audio books, home recording studio, etc... All my other experience was at radio, TV, and production house studios. So I am trying to educate myself ASAP. I appreciate all your observations and comments.
Thank you so much for mastering Chapter 1. I will try to duplicate your process now.
Thank you so much.
Sincerely, Laura