A cheap "grotbox" speaker previews worst-case consumer playback

A cheap, low-quality “grotbox” speaker (or small all-in-one boombox), listened to off-axis from a distance, previews how a mix holds up in worst-case consumer conditions. It is a useful supplementary check for whether the important elements survive on bad systems, but only one such system is needed and you should not obsess over it if your other monitors are used sensibly.

Examples

Playing a mix off-axis through a small boombox reveals whether the hook still reads on the kind of tinny speaker much of the audience uses.

Assessment

Explain what a grotbox speaker checks in the monitoring chain and the caution the author gives about over-relying on it.