Canford Audio 54-304 Sennheiser HD480 headphones limited to 93dBA

Canford Audio 54-304

The Canford Audio 54-304 is a set of Sennheiser HD480 headphones that has been limited to 93dBA. Canford has considerable experience in the design of headphone limiters and their use in the operational environment. Whilst virtually any headphone or headset can have a limiter fitted, using one of the seven types of standard multipurpose limiter circuits, this usually has to be in an in-line housing.

By designing type-specific circuits for individual ear loudspeakers, these can be made small enough and appropriately shaped to enable them to be built into the earcup housing. Adding a limiter circuit to a headphone alters the input impedance.

The Sennheiser HD480 type headphone is an open back type headphone with 1700 ohm capsules. In order to distinguish these headphones from standard non-protected versions, they are distinctively marked on the ear shell. Limiting level is fixed at 85dBA (green trim ring), 88dBA (red trim ring) or 93dBA (grey or blue trim ring) (note 1). Standard connector options are available, and because the limiter is within the capsule, it is possible to use spare or replacement leads, as for standard versions.