A loudspeaker that fails in a customer's hands costs something completely different from one that fails in the factory. Our answer is simple: once a unit is assembled, it goes on the burn-in rack before it goes in a box.
The room is arranged by model, one signal source per row, pink noise alternating with a sweep. Amplifier temperature, quiescent current and any mechanical noise are logged. A unit that fails is opened on the spot and never reaches the next station.
The process is not cheap and it adds days to lead time. It also pushes the dead-on-arrival rate down to almost nothing — and that rate is the hardest thing to absorb on an export project, where return freight costs more than the goods.
