Multiplex (MUX)

A Multiplex (or MUX) is a digital bundle — typically 8 to 18 stations — transmitted together on a single broadcast frequency. A national multiplex operator licences a chunk of spectrum, invites stations to take slots within it, and handles the technical transmission centrally. Individual stations share the multiplex infrastructure rather than each operating its own transmitter network.

Multiplex economics have transformed how new radio stations launch. In the analog era, launching an FM station required purchasing or leasing a high-power transmitter site and navigating national spectrum licensing — a multi-million-euro capital commitment. In the DAB era, a new station can launch into an existing multiplex at a fraction of that cost, which has meaningfully increased format diversity in every market that has completed digital-radio transition.