Too compressed Rejection

Hi to everyone,

I did my second audiobook, I’ve follow all the parameters I got from the forum, in the
other topic, I’ve applied those settings to my second raw files audiobook, they seems ok but

I got rejected because noise floor, even if is only -67
and also some files got Dynamic issue: Too compressed.

here is a sample of that files, what I could do?

Many thanks,

The sound file is “legal”, but it doesn’t sound very good. Sometimes, ACX will reject noise, not because the noise is high, but because you used too much noise reduction or other processing and made the words sound funny.

I don’t think you used ACX Mastering, because your ACX RMS and ACX Peak are off. Again, they’re legal, but they’re not where our mastering usually puts them.

Post about 20 seconds of raw WAV reading — before you did anything to it. One blue timeline just like this first one.

If you don’t have the raw speaking WAV files, make a new 20 second test like this.


Hi Koz.

here is 20 sec raw.
basically I’ve used the instruction you gave me for my first audiobook last month.
I thought they good for all the raw files.

this ebook got 25 chapter and I got rejectet about 7. So may be I did wrong just in those chapter?


That’s it.

Turn on View > Show Clipping.

Screen Shot 2019-05-13 at 3.58.58.png
All those red bands are places where your voice is too loud. Overload like that sounds harsh and gritty. The whole sample you sent has that distortion.

When you record, look at the Audacity bouncing green sound meter. It should never go all the way up and turn red. The sound meter should stay green with maybe a little yellow on the right like this. Yes, it is hard to look at that and read at the same time. Recording quality is what the recording engineer does. You are the recording engineer.

There is no fix for overload (also called Clipping). Once the recording is too loud, it’s forever.

The overload and red bands are throwing the mastering tools off and that’s where the unusual ACX Check numbers are coming from.

Did you change microphones or are recording in a different room? You have a lot of room echo in your voice like you’re recording in a big empty room with bare floors. Also, at about five or six seconds, it sounds like neighborhood noises in the background. Dogs? Kids playing? ACX may not like any of those sounds, but they only complain about the worst problems and the overload is the worst problem.

There’s no easy fix for any of those problems. Echoes and overload are forever. You have to record in a quiet room with no echoes.


It is possible to record in a difficult room, but it’s not cheap. You can use special shotgun microphones. That’s what this guy is doing. That’s many hundreds of dollars.


Thank you KOZ.

My question is: why they wrote this on the issue file:

has Dynamics issue (too compressed) if the problem is overload? Is this overload make compression?

I can try to register again in my room, the problem is I got a flat 20square meters, in the UK unfortunately the quality of building are terrible basically.
You can hear a lot of noise from the neighborood. But the other books I’ve done I did in the same flat with the same hardware.

I’m not using audacity to recorder because my laptop fan is too noizy and I prefer use a sony voice recorder.
I will try to register them again :unamused:

has Dynamics issue (too compressed) if the problem is overload? Is this overload make compression?

The short answer is yes. One of the reasons taxi radios, aircraft radios and police radios sound like they do is clipping and overload. Distortion sounds loud. The goal of these radios is to sound loud and dense and get their messages through. They should not have any volume variation or expression.

The goal of audiobooks is to have a perfect, clear, theatrical performance voice. My joke is listening to someone telling you a fascinating story over cups of tea. Not ordering a cab or landing a plane.

My stand-alone recorders all have a way to set recording volume and most of them have a simple sound meter. Which recorder are you using? Model numbers? You might just have it turned up too loud.

I have all the parts needed to build a simple, tiny sound studio with hardware store plastic pipes and blankets, heavy towels or furniture moving pads. It knocks down for storage. Any second now I’m going to build it and take pictures.

One of the other posters pointed us to a performer who threw a blanket over himself and recorded a test that way. It sounded great, but you can’t breathe after a while. So something a little bigger than that for the home reader.


I shot this on a stand-alone voice recorder. This is the story-teller, conversational tone.

It’s clear, noise-free, sounds just like me and passes ACX Check after mastering.


I’m using this

I did put the low volume settings already before do the recording.

is any hardware I can buy to create a environment like your audio?

what about this test? I did mastering again from the raw file, sounds the same?

How did you shoot the first book?


Do you mean the Spanish one? The first my post I did last month?
If yes, same voice recorder, different flat (my Spanish neighbor flat) carpet floor
Audacity mastering suggestions!

That’s it.

I lowered the volume of the microphone, then I’ve put a foam on top of this, is rudimentary solution but it sounds quiet better? :laughing:

What is that test before you did anything to it? We should hear the raw sound file.

Mastering hides sound damage and we don’t know what to tell you if somethings goes wrong. The audiobook people are searching for performances that sound like somebody is trying to cover up damage.


I could not tell from the Sony instructions how to set recording volume. They tell me there is another instruction manual inside the recorder and they do not publish it on-line. I know the volume control on the outside of the recorder is for playback. It says that. There is no mention of setting recording volume.

The foam is a good idea, but too much foam can cause your voice to sound muffled like you have a towel over your face.


There is another problem with your recorder but I’m ignoring it. The recorder is MP3 only (one of the reasons it’s so affordable) and has a maximum MP3 sound quality of 128. So far so good. That’s the quality that ACX wants you to deliver. The problem is Audacity Mastering, or any correction lowers the bitrate. You can’t edit a 128 performance and end with a 128 show.

You either have to start with a quality higher than 128 or use WAV format and convert to MP3 later. That’s how my recorders work.

Regular WAV sound files have a quality of 2822 stereo, 1411 in mono. Way higher than your recorder. Sometimes people don’t notice you’re violating the rule and that will be our secret.


Koz basically I’m exporting MP3 audio at 320 not 128 if that could be better?
All the file you’ve heard from me they’re 320 !!!

yes there is a set up to put the volume low, which I did already. For now I’m recording all those file again with the foam, I will master and send to ACX again, then I will improve my audio quality, I will buy another microphone, unfortunately I can’t recorder with my laptop on because the fan is very noisy. I need something very quiet. May be a good microphone, + an ipad + garage band to send the audio file into it could be good?

All the file you’ve heard from me they’re 320 !!!

Excellent. I can’t tell that from the information Sony publishes outside of the recorder.

yes there is a set up to put the volume low

Terrific. Again, that information is not available to me.

I will master and send to ACX again

Before you do that, I am constructing a tiny sound studio that fits on a dinner table. You will need that to help with your kids playing outside and dogs barking…and room echoes. When it got dark this evening, I was up to a quick test construction on the table in the back yard.

I’m making it from home store plastic pipes and furniture moving pads. That’s it. I build a little tunnel with the pipes and then throw the blankets over it. Put the recorder inside and listen to the room (neighborhood) noises go way down.

I need to write down the measurements and the parts list.

If you’re in a metric country, you’ll need to figure out what “Half-Inch PVC Pipe” looks like. And cut the pipe. It’s possible a good hardware store may do it for you. I’m trying to make the construction as simple as possible, but sooner or later, you’ll have to cut the pipe. It comes in 2M or 3M lengths.

As we go.


Thanks Koz, take a PVC pipe cut it and put the recorder inside is quiet simple for me. I got all tools need to cut it. Good Idea

anyway now I did record again those chapter, even because this audiobook is about 27 chapters and just 11 of them got rejected.
I did the record early morning when it was really quiet.

Anyway I would like to have a solution like your audio cheapest as possible because now I’m not making any money from ACX and I got
just a normal food delivery job haha!!!