What is A/B Testing?
Also called: A/B comparison
A/B testing in audio means switching back and forth between two versions of a sound, mix or master to decide which is better. Version A and version B are compared under the same conditions.
It is used for all sorts of decisions: two mixes, a processed and an unprocessed signal, two masters, or your track against a reference. The quick switching is what makes it useful, because memory for small differences in sound fades within seconds.
The most important rule is level matching. If one version is even slightly louder, it will usually seem better, so match the loudness before you judge. Blind testing, where you do not know which version is playing, removes the remaining bias.
Listen for specific things on each pass, such as the vocal level, the low end or the punch of the drums, rather than an overall impression.
Put it to work
Upload two versions of a track and get a side by side comparison.
Compare Two Audio Files