ACX Test Analysis

— Noise —

Room Tone or background noise is the sound left after you stop talking.

It's very difficult for home recordists to meet -96dB to -60dB because most people's houses or apartments are a festival of pumps, hums, pet noises, computer fans, traffic, jets and other people.

Microphones make electrical noises, too, and that noise is lumped in with the total.

-60dB is like walking alone into a quiet, peaceful cathedral and -96dB is like walking into an anechoic chamber at NASA. You have to hit it between those two.

Noise Reduction is not the answer.

ACX would just as soon you not use patching, rescue and clean-up tools on your show. The tools can very easily distort the sound and give honky cellphone or highly processed on-line conference sound.

The target sound quality is listening to a friend tell you a story in a quiet room over cups of hot tea.

— RMS (loudness) —

RMS is a technical measurement of the energy in your voice, roughly loudness.

Sound between -96dB and -23dB is too quiet and between -18dB and 0dB is too loud.

— Peak —

This is a measurement of the loudest point in the show. It refers to the extreme tips of the blue waves on the timeline, generally between -3.0dB and -3.5dB.

0dB is where the digital system runs out of numbers and starts creating sound damage and distortion.

Sound peaks between -3dB and 0dB are too loud and forbidden.

My final WAV production tools are set for -3.2dB to allow for tiny conversion errors between the show's WAV sound archive and MP3 audiobook submission.

— Help —

You can ask questions on the Audacity Help Forum.

The forum is moderated, so even if you log in, your question may not appear immediately. Don't double post.

2015-05-23