Struggling to be in ACX standards

Hi guys, I’m try to record a new audiobook, recording with my laptop windows 10.

I do the records, then I’ll try to master and I have struggling to be in the ACX standards all the time

Here is the raw file, any suggetions?

Many thanks

The voice volume is too low and the background noise is too high.

The sound file can’t be fixed. You will have to adjust how you record the work. Describe how you record, your microphone and the room.

Use these instructions to post a voice test.


Thanks Koz, in this room I’ve done already other books, but I was using the voice recorder. I’ll try to use a bit more high volume to record?

here is a sample

Still too low.

I’ve done already other books, but I was using the voice recorder

You really need to flesh these things out a lot more for us to follow you.

How did you do the other books? Is Voice Recorder an APP or a real hardware thing and what are the makers and model numbers? Pretend we’re trying to buy the stuff you’re using.


it was a sony voice recorder, I thought you did remember my other posts last month, anyway now I bought a microphone which is not really good quality but is much better than the voice recorder, my neighbor did register with his mac, I did edit straight away and this pass the ACX check straight away without any rejection.

So for now, I have to record again with a higher record volume?

The problem with your file is that you and your noise floor are too similar in volume. You are too quiet to pass ACX requirements. Making the audio loud enough where your voice is acceptable makes the noise floor too loud too. The noise floor, at base, is probably fine, but in order for you to work with it, -you- must get louder.

Either you need to be closer to your recorder, or you need to speak much, much more loudly. Possibly a combination of both. You can also always try to make your noise floor even quieter, if possible, which will allow you to increase the gain a bit more, but I’d focus more on mic position and your own loudness.

When you recorded that last sample, there was a lot of extra noise in the first two seconds, which should just be complete silence too, as far as you control. My ears aren’t good enough yet to identify what they are. There are five notable sounds in those two seconds though. Some sound like they might be a mouth noise, others sound like little clicks, like maybe a loud clock, tapping on a table, or you shuffling around? You definitely don’t want those in your audio when you’re going for silence.

I thought you did remember my other posts last month

I have trouble remembering where I put my car keys from this morning. This is a forum not a help desk and you won’t always get the same helper elf time after time, and any poster can jump in to help.

This is a lot worse than you think because in the case of audiobooks, everybody has similar problems. No normal human can keep up.

Search the forum for “ACX Noise.” 184 hits. You’re probably in there somewhere.

We have to build your world in our heads immediately based on your quality information in the first posting. Nobody can remember last month’s post.

If you tell us exactly what recorder you are using, we can look it up and tell you how to set the recording volume. Most of them have some sort of volume meter.


ok I understand thanks a lot!

here is a new sample with record volume set in 0.20 and 0.15 it was 0.10 the first sample I’ve post yesterday
it looks with 0.15 recording volume I’ve mastered and the file looks meet the ACX standards

You should be including about 2 seconds of room noise at the start of the file, and aim for about 15-18 seconds of speaking after.

In your first file, the .20 volume one, I can hear a dog barking, or maybe some children playing, at the start of the file. It’s actually so clearly picked up you can hear it continue while you’re talking. Mic’s are very sensitive.

I ran the second one through Audacity directly. I applied EQ, RMS normalizer, and a limiter. Your show’s noise floor hit the -50.5dB mark, which is much, much too loud. I applied noise reduction of the beast (6,6,6) and it was still way too far off. Applying another coat of noise reduction got it to 62.5dB, which will get passed via automation.

However, there’s no chance it’ll get past a human ear. It makes you sound like you are announcing to a very large room through a very bad PA system.

The problem here is that you aren’t loud enough compared to the room tone. You need to get closer to the mic, or get quite a bit louder, when you talk, this way when you do the RMS normalize step you don’t end up needing to amplify the room tone as much. Or you need to get the room much quieter.

I live in the middle of nowhere, and I still try to record at night for example. It lowers the noise floor the tiniest bit because the highway in the distance isn’t as busy. I can’t hear cars in my audio even in the day, but the noise floor raises all the same. I’ve heard of people making very tight and uncomfortable offices to work in inside of their closets, making things more sound resistant and echo free by hanging blankets on the wall and filling in the overhead space with extra cloth.

ok I’ll try to do again this night with a 0.30 recording volume and my voice higher.!!! Thanks a lot for now

Keep in mind, recording with more mic gain also means that it’s going to also increase your noise floor. It’s less about you getting louder, and more that you and the noise floor get further and further apart.

At one point, to make it so I could get closer to my mic, I considered hanging it from the ceiling and marking a place on the ground for me to stand so I’d always be a distance that worked for me, but thankfully I found another solution. You can get louder by both talking louder, and you can also get louder just by getting closer. Personally, what works for me and my current project, is that I’m about five inches away from the mic, and talking to it indirectly. I’m off to the left and speaking past it into the void. It makes my voice sound a little colder, which suits the sombre tones of the book more than my voice normally would. But I’m so close so I don’t end up sounding like a whisper.

ok, I’ve found in my town a Pirate studio, they rent for £4 hour a recording studio room, where the band do rehearsal, it looks nice with my recording volume at 0.25, I can hear the bus drive out there the room is not really without noise at all but better than my young couple with 2 babyes :laughing:

Did you already apply effects to this file? That isn’t going to get you a ton of help on the forums. We want the raw .wav without any processing effects done to it.

Your room tone is still probably going to fail you unless you work on getting better quality. It’s supposed to be completely silent, and it’s one of ACX’s requirements. In your first two seconds I can hear what sounds like a keyboard press (or someone pushing down on a tab on a soda, whatever) and also your chair shuffling. You need to make sure you are completely silent. Even leave the room and come back in if you need to to get a pure sample of room noise! You can trim off the extraneous bits after.

This sample as it is passes the robot ACX checks though, yes. Did you apply noise reduction at all?

oh yes I forgot the raw file there, I’ve applied mastering as audacity instruction
RMS Normalize
then noise reduction -12db
then normalize as well

If you listen to the latest two samples you posted side by side, you can hear a really clear difference between the two. Ignoring the background noises and sounds, the unedited one sounds more pleasant on the ears. The one you applied 12dB of noise reduction to, to make it fit the ACX robot requirements, makes you sound a bit metallic.

ok thanks I should apply just 6 noise reduction?

I don’t think that would be enough to get it into the guide lines, though six is a much gentler number that doesn’t effect things too poorly. You can keep messing with the settings and see if you can find something that works for you though. Other than, once gain, getting louder, or closer to your microphone though, I’m not sure what more advice I can give you. It seems kind of like you just live in a noisy area!

ok is a pirate studios room where band do test, I’m going there 6am which I’m just my self ! I’ll try to set up the volume record of audacity on 0.30 tomorrow let’s see if will be better! Many thanks

here is my new raw test in pirate studio room 7 today thanks