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.
All types have interwoven copper/Kevlar cables for extra strength. As with in-line limiters, each headphone is individually calibrated, and as each capsule has its own individually calibrated limiter, spare limited capsules are available.
Single-sided cables connect to the left earpiece, with a loop over the headband to the right earpiece; a fixing kit is supplied to hold the cable onto the headband. Note that in these versions, the earpieces are mounted onto the headband the opposite way up (connector at the top).
Frequency response: 20-20000Hz. Input impedance: 1200 ohms per earpiece. Sensitivity: 91dB for 1mW. Weight: 140g
Closed ear designs with extremely high external noise attenuation. Flip-away earcups, can be locked securely in place. High wearing comfort due to a splittable headband and leather-effect earpads. Single-sided, coiled 1.5m cable (3m extended), steel cored for reliability, supplied fitted with a straight 3.5mm 3-pole jack plus adapter to 6.35mm A-gauge 3-pole jack plug.
Impedance 70 ohms. Frequency response 16-22000 Hz, 200mW load rating.
Limited spare cables
HD280 PRO
Closed back circumaural headphones with high noise attenuation. Folding and rotating ear cups have been integrated on this updated version for easier transportation. Single-sided coiled cable with 3.5mm 3-pole jack, plus screw-on adapter to 6.35mm jack. Frequency response 8 to 25000Hz. SPL 113dB. Weight 285g. Nominal impedance 64 ohms. Supplied limited at 88dBA.