Setting ACX parameters.

I have received this set of parameters from ACX . Since I will be using ACX 2.1.0 I am seeking guidance to meet these settings.
Recording Using HP Envy m6 notebook PC , Windows 10, logitech USB headset H530.

Simply a direct link to the where in the user manual would be a time savings. Likely the Robot will let me know otherwise…ACX Deadline pending. Thank You

have room tone at the head and at the tail and be free of extraneous sounds

Record in a quiet room and don’t use a noisegate or noise reduction which will kill “room tone”.

measure between -23dB and -18dB RMS and have -3dB peak values

You can set the peak with the Amplify or Normalize effect. Note that the peak may go up by one dB or so with MP3 encoding (or other lossy compression)

The ratio* between RMS & peak doesn’t change when you change the volume linearly.

You can check the RMS level with Analyze → Contrast.

You can reduce the difference between peak and RMS with limiting and/or dynamic compression. (Practically speaking there’s no way to increase the difference between RMS & peak.)

and a maximum -60dB noise floor

Record in a quiet room. Speak with a strong voice reasonably close to the microphone (for a strong signal-to-noise ratio). Use a good low noise interface/preamp (or a good USB mic.) Check the noise floor by running Analyze/contrast on a “silent” section (with only “room tone”). Getting a low noise floor in an amateur “studio” can be difficult.

logitech USB headset H530.

If that works for you, fine. But, you may need a good USB [u]podcast mic[/u] or reasonably good “studio style” mic with an appropriate [u]USB audio interface[/u]. (A regular soundcard won’t work with any stage/studio mic which will be low-impedance balanced with an XLR connector, and it may need phantom power.)

If you do buy a desktop/stand microphone, it’s probably a good idea to also invest in a [u]pop filter[/u]. A pop filter will allow you to get closer to the mic without getting pops or other breath noises, and it can help you keep a consistent distance from the mic.


  • Decibels are logarithmic, so the difference (subtraction) is a ratio.

You can check the RMS level with Analyze → Contrast.

You can check all the ACX specifications in one go with ACX Check.

Download and unzip that file and copy acx-check.ny over to your Audacity plugins folder. Restart Audacity.

Select your performance by clicking just above MUTE. Analyze > ACX Check.

The important numbers are Peak Level, RMS Level and NoiseFloor (not “A”).

Record in a quiet room.

What he said. Room Tone or background noise kills home recordings.

Screen Shot 2015-08-17 at 19.32.40.png

After you make it past the ACX Quality Control Robot, it has to sound good and you have to be able to read. That’s the “Oh, right” moment.

I have a USB gamer headset that works OK, but nobody is giving me any awards for theatrical sound quality. I do have an actual production headset microphone that does work well. That’s how I shot this sound test, but this microphone does take a sound mixer.

I really need to record that over again…


There is documentation for ACX Check on the Audacity Wiki where you can also download it


I’ve been looking for that. I have the old original version. The first one that was useful.