A head unit is the central control module of a car's audio and infotainment system — the component mounted in the dashboard that manages audio sources, display output, navigation, and connected devices like phones.
A head unit replaces or upgrades the factory radio and serves as the hub everything else runs through: amplifiers, speakers, backup cameras, and smartphone integration systems like CarPlay and Android Auto. Modern aftermarket head units run full Android operating systems, support wireless phone mirroring, and include touchscreen displays ranging from 7 to 12 inches. The head unit is distinct from amplifiers and speakers — those are downstream components the head unit drives, not part of the unit itself.
- Standard head unit dash slot sizes: single-DIN (2 inches tall) or double-DIN (4 inches tall).
- Aftermarket Android head units commonly ship with 2GB–4GB RAM and 32GB–64GB internal storage.
- Head unit display sizes in the aftermarket segment typically range from 7 inches to 12.3 inches diagonal.
- A head unit's RCA preamp outputs connect to external amplifiers; most units include 2–4 preamp channels.
- Vehicle-specific head units include a matching mounting frame and wiring harness; universal units require separate adapters.