# A/B comparison

A/B comparison switches a room between two tracks at the same place in the song: your mix against a reference, two masters of one album, or the same song in two formats. You hear the difference at once, without searching for the passage again.

A/B comparison is a plugin. An admin switches it on in **Settings › Plugins › A/B comparison**. While it is off, no comparison starts and one that runs ends.

## Start a comparison

1. Play track **A** in the room.
2. Open the menu of any other track (in search, an album, a playlist, favorites or Up next) and choose **Compare as B**.

The room keeps playing at the same place, now from the comparison. The A/B key in the player and in **Now playing** shows which side plays.

## Switch sides

- Press the A/B key, or
- press **A** on the keyboard in the web UI.

The other track continues at the same place in the song.

## Match loudness

A louder track sounds better at first, even when it is not. **Match loudness** (on when a comparison starts) plays both sides equally loud, from the loudness bitwerk measured for each track. Now playing shows the gain of each side. While it matches, the player computes the level, so the room’s badge says **DSP**. Switch it off to hear both tracks as they are.

## End the comparison

Press **Stop** under **A/B comparison** in Now playing. The comparison also ends when Up next moves on to another track.

Source: https://bitwerk.systems/software/ab-comparison/