Sennheiser HDA 280 manual Audiometric headphones, Specifications, Frequency response curve

HDA 280

Audiometric headphones

Design approved by the PTB (German national institute for science and technology).

The headphones comply with IEC 60645-1.

Important!

The HDA 280 is designed for use with an audiometer!

After exchanging audiometric headphones, the audiometer has to be re-calibrated!

Specifications

Cat. No.	9860	1 unit
	9861	24 units/carton
Transducer principle	dynamic, closed
Ear coupling	supra-aural
Frequency response	< 20 Hz to > 20 kHz
Characteristic SPL	117 dB (at 1 kHz, 1 mW)
Max. L/R deviation	125 Hz – 4 kHz < 1.5 dB
	4 kHz – 12 kHz < 2 dB
Max. nominal continuous	500 mW (as per EN 60268-7)
input power
Nominal impedance	37 Ω
Contact pressure	5 N ± 0.5 N
Connection cable	approx. 3 m, open-ended
Weight (with cable)	330 g
Connection code	green	+ L
	copper	– L
	red	+ R
	copper	– R

measured at normal climate: temperature = 20 °C,

relative humidity = 50 %, atmospheric pressure approx. 100 kPa

Frequency response curve

dBr
+140
+135
+130
+125
+120
+115
+110
+105
+100
+95
+90100	200	500	1k	2k	5k	10k
			Hz

Measured with B&K 4152 as per IEC 60318-3

Headphone input voltage 500 mVrms

Pure tone RETSPL

	Pure tone reference equivalent					Max. SPL
	threshold sound pressure level				on B&K 4152 < 10 min.
Frequency (Hz)			dB (re 20 µPa)				dB (at 4 V)
125		38.5		143 ± 3
250		25.0		144 ± 3
500		13.0		144 ± 3
750		9.0		144 ± 3
1000		7.5		145 ± 3
1500		9.5		145 ± 3
2000		8.0		138 ± 3
3000		6.5		133 ± 3
4000		9.5		137 ± 3
6000		19.0		132 ± 5
8000		18.0		122 ± 5
*
		18.5		110 ± 5
10000
12500		30.5		122 ± 5

Reference equivalent threshold sound pressure level (re 20 µPa) for the HDA 280 headphones and a coupler as per IEC 60318-3

* additional values following ISO 389-1

Peak-to-peak RETSPL

For clicks, 20 Hz

–on an ear simulator as per IEC 60318-1 and

–on an acoustic coupler as per IEC 60318-3

pe RETSPL = 31.5 dB (re 20 µPa).