Quality Troubleshooting

That works. There’s still some what sounds like air conditioning or wind noise in the background, but it’s so low in volume it doesn’t make any difference.

This is your clip fully mastered with gentle Noise Reduction of the Beast.

A word on how to listen to this. Roll it forward and set the voice volume for pleasant listening. Roll it back and listen to the noise. Do Not Touch Anything. It should be almost not audible.

Quick Studio Notes:

The hanging material looks like a shower curtain. That’s “Hollywood Soundproofing.” Looks great, doesn’t do anything. Regard my portable soundstudio.

That last one is an actual movie voice shoot.

Each one of those walls has two furniture moving blankets and there’s four walls, plus one on the floor.

At fifteen pounds each, that’s 135 pounds of blankets in that shoot not counting the wood and screws.

That’s been through four sound shoots and I got really good at building and tearing it down.

We moved buildings and the new place had a fully soundproofed conference room. No more blankets. Yay!!

This is another application for the blankets. Kitchen Table Sound Studio.


With reference to the last shot in your series. Your desk. What happens if you hit one of those pipes with a pencil? DINK! It sounds like a pipe, right? What can you do to deaden them? Wrap them with fabric gaffer’s tape. Throw towels around? Packing foam doesn’t work. It has to be heavy and dead.

Costco has a bale of cotton hand towels for cheap. Each one 28" long. Drape as needed.

Keep the screens at a very slight downward or upward angle. Not straight.

Fold up a moving blanket or bath towel on your desk. In the kitchen table studio, one of the blankets is doubled up on the desk.


You might be able to use the structure of what you got, just go visit JoAnn Fabrics and get several yards of something heavy like denim or flannel.

Monks Cloth and burlap would work. That may cost more than furniture blankets, but you can customize the colours and patterns.

I may be the only shopper at JoAnn’s completely ignoring the colors and patters and shopping for dead weight.

One time I went shopping for microphone wind sock material. I wrapped the material around my head to hear what it would do to the sound.


What happens if you hit one of those pipes with a pencil?

In general you only need to worry about stuff relatively close to the microphone. The desk and parts. Those lighting stanchions back there don’t matter.


All that and you don’t have to change anything. This does work as it is.


Excellent. I replaced my fan and heatsink, my computer is now nearly silent.

Eventually I plan to upgrade the curtaining, but for now it reduces echoing and by doubling up on them it does genuinely reduce what little noise there is left. Monitors are facing downwards, sound is good.

The only question I have left is whether or not my final edits should include compression; my wife thinks it sounds better and it lowers my sound floor to a place where it’s excellent.

I was able to get -78.22db after running filter curve, loudness normalization, a compression add-on, limiter and then noise removal. Without the compressor, in that same order, I was -71.38 on the same file. Is there ANY reason not to do this?

Echo reduction is relatively easy because your voice has to go through the curtains twice. Once on the way out, bounce, and then again on the way back. It decreases at each step. The return on investment is pretty good.

We publish known working recommendations. If you find something that works for you—and passes ACX testing—at ACX—go for it.


Make-up-gain on the compressor will inevitably increase the noise-floor to some degree.

inevitably increase the noise-floor to some degree.

I’ve never seen a compressor make noise better either, but. Is there a noise gate built in? Could that be what the Noise Floor setting is?


If that’s what it is, you should be careful with it. If it’s set to the exact or close to the actual noise volume, you could get background noise pumping or noise shifting in and out. ACX hates sound processing like that.

Compressor settings are not for the easily frightened.


If the make-up-gain is ticked, everything on the track will be amplified to some degree if compression has been applied, not just where the compressor has been active.

I have seen compressors which will noise-gate (i.e. expand) at the same time,
e.g. … “Red Phatt Pro” by Jeroen Breebaart (Windows only).

And yet. The posters noise seems to have gotten 7dB better with the compressor.


I was able to get -78.22db after running filter curve, loudness normalization, a compression add-on, limiter and then noise removal. Without the compressor, in that same order, I was -71.38 on the same file.

I don’t like tools that do unpredictable or contradictory things.


What are your noise reduction settings and are they always the same?


Maybe their compressor includes low & hi pass filters that remove infrasound & ultrasound which would contribute to an unweighted noise-floor measurement, but their presence/absence would not be audible.

includes low & hi pass filters

They folded it into Mastering whose first step is the Low Rolloff rumble filter.

If there was ever a post that prompts the Puzzled Puppy Look, this one is it.

Apparently, its a third party compressor which makes it much more difficult to find the manual.



Yep, I’m using the same compressor settings from the top.

What I was using was the audacity compressor-- After a few more attempts, I noticed that it sometimes sent my peaks outside of the ACX standards, so I stopped playing with it-- no need for the time being.

I’ve been using it for years, but one of the first things I noticed about all the stuff we do for ACX was that it was very much like a step by step version of compressor. I still think it sounds better, but as you said, unpredictable=bad.

As for me, I’m going to get a small portfolio going by reading public domain stories and original stories on a Youtube channel, as well as my own novel, and make ACX samples out of my most promising raw files. I did a reading of my entire novel once already, 18 hours of work to find out that it wasn’t fit for a standard I didn’t know existed previously, but I got a lot of practice, so it’s all worth it. Now for the fun part.

Thanks for all your help guys.


There is a recent forum posting: “Now that I’m done reading my book, help me pass ACX.”

I swear I’m going to publish “Common Mistakes.”


That’s a GREAT idea. I KNOW I would have used it. I made a lot of use of the information in these forums before I even posted.

I was considering making a short synopsis of how this played out here, but you guys are the genuine experts, as expert as any of this gets anyway; your words on common mistakes might be as useful as anything on the Audible Audiobook Mastering Wiki.

I KNOW I would have used it.

How would you find it? Half the fun with this stuff is organizing and presenting. The Audacity wiki/FAQ has a lot of stuff in there, but it’s difficult to find anything without annotating some of it like I did.


I would expect to find it in a subsection under “Notes and Comments,” probably with a few bullet points and an expanded article hyperlink so you don’t clutter the page too much, since it seems to be well organized already.

Things like:

  • Don’t record a single narration in multiple locations.

  • Drink lots of water an hour awhile before narrating to avoid saliva noise.

  • Record each chapter or subsection into a separate file <120 for mastering.

I imagine it would be something you would slowly add more and more to.

you would slowly add more and more to.

That’s one of the problems. We can do two pages before lunch.