Headphones
HME 27 
Transducer principle
dynamic, closed
 
Ear coupling
circumaural
 
Frequency response
8 Hz to 18 kHz
 
Impedance
64 Ω
 
Load capacity
500 mW
 
Sensitivity
112 dB SPL/1 V rms/1 kHz (ActiveGard™ switched off)
 
Maximum sound pressure level
ActiveGard™ switched off: 128 dB SPL @ 1 kHz
ActiveGard™ switched on: 110 dB SPL @ 1 kHz
 
Ambient noise reduction
Max. 32 dB (passive, ANR switched off)
 
Total harmonic distortion (THD)
< 0.1% @ 1 kHz, 100 dB SPL
 
Contact pressure
approx. 3.3 N
 
HMD 27 
Transducer principle
dynamic, closed
 
Ear coupling
circumaural
 
Frequency response
8 Hz to 18 kHz
 
Impedance
64 Ω
 
Load capacity
500 mW
 
Sensitivity
112 dB SPL/1 V rms/1 kHz (ActiveGard™ switched off)
 
Maximum sound pressure level
ActiveGard™ switched off: 128 dB SPL @ 1 kHz
ActiveGard™ switched on: 110 dB SPL @ 1 kHz
 
Ambient noise reduction
Max. 32 dB (passive, ANR switched off)
 
Total harmonic distortion (THD)
< 0.1% @ 1 kHz, 100 dB SPL
 
Contact pressure
approx. 3.3 N
 
HMDC 27 
Transducer principle
dynamic, closed
 
Ear coupling
circumaural
 
Frequency response
8 Hz to 18 kHz
 
Impedance
600 Ω (ANR switched on)
200 Ω (ANR switched off)
 
Load capacity
500 mW
 
Sensitivity
112 dB SPL/1 V rms/1 kHz (ANR switched on, ActiveGard™ switched off)
107 dB SPL/1 V rms/1 kHz (ANR switched off, ActiveGard™ switched on/off)
 
Maximum sound pressure level
115 dB SPL @ 1 kHz (ActiveGard™ switched off, ANR switched on)
128 dB SPL @ 1 kHz (ActiveGard™ switched off, ANR switched off)
110 dB SPL @ 1 kHz (ActiveGard™ switched on, ANR switched on/off)
 
Ambient noise reduction
Max. 32 dB (passive / ANR switched off)
Additional max. 15 dB (ANR switched on)
 
Total harmonic distortion (THD)
< 0.1% @ 1 kHz, 100 dB SPL
 
Supply voltage
Phantom powering P12–P48, 12 V to 48 V, 10 mA
 
Contact pressure
approx. 3.3 N