Yes. As expected, they are approximately in line with the figures reported by Michael Taddeo.
The RMS level reported by “Contrast” (-38.31) is a little lower, than reported by Michael (-35 dB), because ACX exclude long silences when making their measurements.
So, in short, Michael is correct, the MP3 that you sent to him is too quiet.
My guess is that in your Audacity Project, the track “Gain” slider (Audio Tracks - Audacity Manual) is not at zero.
The Track Gain slider changes how loudly the track plays, and the exported track takes that into account. The track gain slider should be set to zero, otherwise measurements of the track level in Audacity will not be the same as the exported file.
Thanks for that. I will check all of my work before I resubmit. Should I wait until I hear from Greg after he has contacted ACX?
If I do as you suggest, are there magic numbers, and where will they be (like contrast which I did not know existed), which will tell me that ACX would be unlikely to reject what I send them?
I have been doing this going on a year now. I have never found a physical instruction book with pictures written in layman’s language for non-technical people. For the likes of me, and anyone else who might want to get into this, the information on websites and on YouTube is difficult to follow, especially when it is on the same screen that you are working on.
Such a book, for example, How To Create an Audiobook for Amazon associated businesses using Audacity software would find an eager following over time.
I would be more than capable of writing and producing that, and I just thought I might run the idea past you and/or your colleagues to see if Audacity might be supportive in providing the legitimacy of technical scrutiny that such a work would require.
Should I wait until I hear from Greg after he has contacted ACX?
Don’t wait. Your posting of the short chapter (thanks for that!) cleared a lot of the questions and seeming contradictions. I shared some of your work with Steve. Our tools and diagnostics are a lot closer to each other than it seemed.
I have been doing this going on a year now. I have never found a physical instruction book with pictures written in layman’s language for non-technical people.
It is a technical task. I saw a clip on TV of TV personality reading his own book. There was a producer/engineer on the other side of the glass apparently doing the recording and every once in awhile the producer would ask the talent to re-read a sentence or paragraph. Or, maybe there was recording engineer that wasn’t visible in the shot. And, there may have been another engineer (or maybe the same engineer) doing the editing & level adjustments in post-production.
I really am grateful for your interest. You have provided information, which I cannot understand as I am not a technical sound engineer, but you have not answered my question. I have 25 files which I sent to ACX as you know. They all appear to be within ACX stated requirements, yet they have been rejected. Obviously I don’t want to start all over again. If nothing else it has given you renewed confidence that ACX Check is a reliable approximation of what ACX themselves use. That is all very well, but it doesn’t solve my problem.
So I need to know what is the significance of the CONTRAST reading, and do I need to satisfy that? If so how?
Do I need to get WAVSTAT? How do I use that and what will it tell me?
Do I need RMS NORMALIZE? How do I use that and what will it tell me?
But above all what NUMBERS should I be aiming for to satisfy ACX, given that I have already achieved the ones that I know. Please try to make it simple. Have pity on me.
The file “NEW CHAPTER FIFTEEN LAME ACX MCCD.mp3” is NOT within ACX stated requirements.
The “Contrast” tool is Audacity’s built-in effect for measuring RMS level. The reason that I suggested using “Contrast” is that it rules out any (unlikely) possibility of you having an old or faulty version of a third party plug-in. By using this tool, I know with certainty that you are using the same tool that I’m using.
The RMS measurement from “Contrast” should agree with the RMS measurement from the ACX Check plug-in AND the WaveStats plug-in. When measuring RMS, they are all measuring the same thing, so should all give the same result (give or take a small error margin).
You previously wrote that when you imported “NEW CHAPTER FIFTEEN LAME ACX MCCD.mp3”, the Contrast tool measured the RMS level as “-38.31” dB.
Please repeat that test, but use “ACX Check” to measure the RMS level. ACX Check should also say that the RMS level is around -38.3 dB. Does it?
You will be as pleased as I am relieved that ACX finally passed my recording of More Dark Drink & Conversations which is now available on Audible.
What to learn? Start of by Normalising to 0.3. Run an ACX check every 5 minutes both during recording and after applying the LAME MP3 conversion. Lots more …… I think I will write a book. Thanks for your help.
Part of the mastering design is making sure we don’t cure problems that only happen to one person. You have non-typical problems that are causing puzzled looks among the elves.
Why don’t you publish here. Our mastering suite isn’t the only way to do this particularly if you have very difficult sound problems. It’s the simplest assuming you got close with the reading.
Run an ACX check every 5 minutes
I bet that’s a grayspires problem. Most people can read for a very long time without drifting outside of generally accepted recording standards. If you find yourself continually drifting away, it is highly recommended that you wear headphones and listen to yourself as you record. That one step goes a very long way to stabilize recording volume.