Sennheiser 502399, 523983-A01, HMEC 26 User Manual

HMEC 26

Instruction manual

Safety instructions

y Please read these instructions carefully and

completely before using the headset.

y Make these instructions easily accessible to all users

at all times.

y Always include these instructions when passing the

headset on to third parties.

y During flight operation, do not use the headset for

telephone calls.

y With the NoiseGard™ active noise compensation

switched on, typical aircraft sounds (for example,
those from engines, propellers, warning alarms, etc.)
may sound different to you. Before operating any
aircraft, make sure that, with NoiseGard™ switched
on, you can hear and recognize these sounds. Set the
volume to safe levels that do not interfere with your
ability to hear informational sounds and warning
alarms.

y The headset is capable of producing sound pressure

levels exceeding 85 dB(A). In many countries 85 dB(A)
is the maximum legally permissible level for
continuous noise exposure during the working day.
Exposure to sounds of higher volume levels or for
longer durations can permanently damage your
hearing!

y Never repair or attempt to repair a defective headset

yourself. Contact your Sennheiser agent or the
Sennheiser Service Department.

1

y Only replace those parts of the headset whose

replacement is described in this manual. All other
parts of the headset must be replaced by your
Sennheiser agent.

y Protect the headset from humidity. Use only a slightly

damp cloth to clean the headset. For information on
how to clean the headset, contact your Sennheiser
agent.

Intended use of the headset

Intended use includes:

• having read this instruction manual especially the
chapter “Safety instructions”.

• using the headset in jet aircraft and within the
operating conditions as described in this instruction
manual.

Improper use

Improper use means using the headset other than as
described in this instruction manual, or under operating
conditions which differ from those described herein.

2

The HMEC 26 headset

The HMEC 26 headset with NoiseGard™ active noise
compensation features dynamic, closed headphones. The
noise-compensating condenser microphone ensures
excellent speech transmission even in noisy
environments. Designed for use in aircraft cockpits.

Features

y NoiseGard™ active noise compensation reduces

ambient noise by up to 18 dB – consequently the radio
volume can be decreased

y Lightweight
y Extremely comfortable to wear due to the patented

two-piece automatic headband and soft earpads

y Peak level protection (cannot be switched off)

safeguards you from volume peaks above 110 dB

y “Flip-away” headphone allows single-sided listening
y Flexible microphone boom, can be worn on either left

or right-hand side

y Noise-compensating condenser microphone ensures

excellent speech transmission

y Single-sided cable, easy to replace
y With NoiseGard™ switched off, the headset can be

used as a conventional headset

y Power supply for NoiseGard™ from aircraft DC power

supply system (on suitably equipped aircraft) or
batteries/rechargeable batteries

y “Auto shut-off” extends battery life
y TalkThrough function (HMEC 26-T only)

3

y ETSO approval C57a/C58a

Delivery includes

y 1 HMEC 26 headset
y 1 cable clip
y 1 wind and pop screen
y 1 instruction manual
y 1 carry bag
y 1 EASA Form 1

Operation

Turning the microphone boom

The microphone boom can be rotated. This allows the
headset to be worn with the microphone boom positioned
on either the left or right-hand side of the head.

4

Putting on the headset

When putting on the headset, the patented two-piece
headband adjusts automatically.

Positioning the microphone

Bend the flexible microphone boom so that the micro­phone is placed at the corner of the mouth. Maintain a
distance of approx. 2 cm between microphone and mouth.
Always use the supplied wind and pop screen.

5

Flipping away one earcup

The headset features a “flip-away” earcup for single­sided listening.

Adjusting the volume directly on the audio system

Connect the headset to the corresponding sockets of your
audio system. Adjust the volume directly on the audio
system.

CAUTION!

6

Hearing damage due to high volumes!

This headset is capable of producing high
sound pressure levels. Higher volumes or
longer durations can damage your hearing!

Set the volume to a medium level. Make sure
that you can hear critical sounds such as
warning alarms.

Adjusting the microphone sensitivity

The microphone sensitivity has been factory pre-set to
80 mV/Pa as per RTCA DO-214. You can change the
microphone sensitivity by turning a small screwdriver in
the direction of the arrow.

+

–

7

The operating controls of the HMEC 26

Operating control I

 Volume controls
 LED

























 NoiseGard™ ON/OFF

switch









 Mono/stereo switch
 BOOM switch L/R
 3.5 mm jack socket
 Battery compartment
 2.5 mm jack socket

Headset with
operating
control I

HMEC 26-BV-K xxxxxxxx
HMEC 26-BV-KP xxxxxxxx
HMEC 26-BV-CP x x x x x
HMEC 26-B-K x x x
HMEC 26-B-CP x x x
HMEC 26-V-KP xxxxx
HMEC 26-V-RP xxxxx
HMEC 26-V-CP x x x x
HMEC 26-V-KX xxxxx

8



Operating element

Operating control II



 LED
 NoiseGard™ ON/OFF



switch

Headset with

Operating element

operating
control II



HMEC 26-CP x x
HMEC 26-KP x x
HMEC 26-NP x x

9

Using the headset

Switching NoiseGard™ on/off

The NoiseGard™ ON/OFF switch  allows you to switch
the NoiseGard™ active noise compensation on or off. With
NoiseGard™ switched off, the headset can be used as a
conventional headset.

왘 Set the NoiseGard™ ON/OFF switch  to the desired

position:
ON: NoiseGard™ is switched on. The LED  lights up,

indicating the battery charge status (see
page 11) or power supply via the aircraft DC
power supply system.

OFF: NoiseGard™ is switched off. The LED  is off.

Adjusting the volume

The two slide volume controls  allow you to adjust the
volume for the left and right channel separately.

CAUTION!

왘 Use the two volume controls  to adjust the desired

volume.

10

Hearing damage due to high volumes!

This headset is capable of producing high
sound pressure levels. Higher volumes or
longer durations can damage your hearing!

Set the volume to a medium level. Make sure
that you can hear critical sounds such as
warning alarms.

Switching between mono and stereo mode

The mono/stereo switch  allows you to switch between
mono (

) and stereo () mode, depending on the

audio system.

왘 Set the mono/stereo switch  to the desired

position: mono (

) or stereo ().

Changing the left and right stereo channel

The position “R” or “L” of the BOOM switch 
corresponds to the position of the microphone on the left
or right side of the mouth. When the microphone boom is
rotated to permit left or right side microphone
orientation, the BOOM switch allows you to correctly
assign the audio channels (L/R) to the appropriate
headphone sides. This enables the correct orientation of
the volume controls and any stereo audio signals. To
move the BOOM switch, use a pointed tool.

Powering NoiseGard™ via two (rechargeable) batteries

왘 Insert two 1.5 V AA alkaline batteries (IEC LR 6) or

two 1.2 V AA rechargeable batteries (IEC LR 6).
Observe correct polarity when inserting the batteries.

11

The operating time with batteries/rechargeable batteries
is approx. 60 hours.

With NoiseGard™ switched on (see page 10), the LED 
provides information on the remaining battery/
rechargeable battery capacity.

LED  lights up yellow: The battery capacity is

sufficient.

LED  lights up red: The batteries are flat.

Replace the batteries.

Activating the “auto shut-off” function

The battery-saving “auto shut-off” function automatical­ly switches the NoiseGard™ electronics off when the
headset is disconnected from the audio system or when
the aircraft avionics are switched off. The headset is de­livered ex-works with the function deactivated. You can
activate “auto shut-off” as follows:

왘 Set the switch to the position ASO.

12

Switching the TalkThrough function on/off
(HMEC 26-T only)

The headset provides excellent attenuation of ambient
noise. In order to allow you to communicate undisturbed
with your surroundings while wearing the headset, the
HMEC 26-T features a TalkThrough function.

왘 Press the TalkThrough button  to switch the

TalkThrough function on. The LED  lights up. Press
the TalkThrough button again to switch TalkThrough
off.

Note:

The TalkThrough function can only be used when the
NoiseGard™ active noise compensation is switched
on.





13

Connecting a mobile telephone

The 2.5 mm jack socket  allows you to connect a mobile
telephone. For this purpose, the NoiseGard™ active noise
compensation must be switched on and the microphone
connector must be connected to the aircraft radio/audio.
A suitable adapter for your mobile telephone with

2.5 mm jack socket is available from your Sennheiser
agent.

CAUTION!

Danger of accident due to reduced attention!

Making telephone calls or operating the
mobile telephone limits your attention and
may cause accidents.

During flight operation, do not use the
headset for telephone calls!

왘 Connect the audio cable to the 2.5 mm jack socket 

on the operating control I and to the corresponding
jack socket on your mobile telephone.

You can adjust the volume of the mobile telephone via
the headset’s operating control. However, the functions
of the mobile telephone cannot be controlled via the
headset’s operating control.

왘 Operate your mobile telephone as usual and observe

the instructions of the manufacturer.

The latest information on cell phone compatibility is
available on the internet site at www.sennheiser.com.

왘 Search under “Products”, “Aviation” and “more info

…”.

14

Connecting an additional audio player

The 3.5 mm jack socket  allows you to connect and
listen to an audio player (not supplied) through the
headset. For this purpose, the NoiseGard™ active noise
compensation must be switched on.

CAUTION!

Danger of accident due to reduced attention!

Listening to music or operating an audio
device limits your attention and may cause
accidents.

During flight operation, do not use the
headset for listening to additional audio
sources!

CAUTION!

Hearing damage due to high volumes!

This headset is capable of producing high
sound pressure levels. Higher volumes or
longer durations can damage your hearing!

Set the volume to a medium level. Make sure
that you can hear critical sounds such as
warning alarms.

왘 Connect the audio cable to the 3.5 mm jack socket 

on the operating control I and to the corresponding
jack socket on your audio player.

15

Care and maintenance

Cleaning the headset

Use a soft, slightly damp cloth to clean the headset from
time to time. If the headset is very dirty, use a cloth
dampened with mild, soapy water. Do not use any
solvents or cleansing agents.

CAUTION!

Replacing the earpads

For reasons of hygiene, the earpads should be replaced
from time to time.

왘 Grasp the edge of the earpad and pull sharply.
왘 Attach the new earpad to the earcup by pressing

firmly around the earpad until you hear all 12 latches
lock into place.

16

Danger of short-circuit due to the ingress of
water!

Water entering the housing of the headset
can cause a short-circuit and damage the
electronics.

Accessories and spare parts

By changing the cables, you can simply retrofit different
operating controls (see page 8 and 9) or connectors (see
page 19) to your headset.

y Cable -CP Cat. No. 500852
y Cable -V-CP Cat. No. 500846
y Cable -B-CP Cat. No. 500837
y Cable -BV-CP Cat. No. 500838
y Cable -KP Cat. No. 500842
y Cable -V-KP Cat. No. 500848
y Cable -B-K Cat. No. 502183
y Cable -BV-K Cat. No. 500839
y Cable -BV-KP Cat. No. 504030
y Cable -NP Cat. No. 500855
y Cable -V-RP Cat. No. 500853
y Cable -V-KX Cat. No. 502437
y Audio cable, length 0.6 m,

with two 3.5 mm stereo jack plugs Cat. No. 520316

y Audio cable, length 0.6 m,

with two 2.5 mm jack plugs Cat. No. 520317

y Headband padding, 1 pair Cat. No. 515629
y Earpads, leatherette, 1 pair Cat. No. 529766
y Earpads, leatherette, 100 pairs Cat. No. 529767
y Hygiene pads HZH 26, 200 pairs Cat. No. 502595
y Wind and pop screen, 1 item Cat. No. 515297
y Wind and pop screen, any quantity Cat. No. 514127

y Carry bag Cat. No. 077408

17

y Cable clip MZQ 2002 Cat. No. 044740
y Cable clip HZC 08 Cat. No. 525787

Cable clips

HZC 08 MZQ 2002

(for round or flat cable)(for round cable only)

18

Product variants

Model Cat. No.

HMEC 26* 502397

HMEC 26-T* 502404

HMEC 26-CP 502402

HMEC 26-V-CP 502405

HMEC 26-B-CP 502398

HMEC 26-BV-CP 502400

HMEC 26-KP 502403

HMEC 26-V-KP 502406

HMEC 26-B-K 502399

HMEC 26-BV-K 502401

HMEC 26-NP 502397 + 500855

HMEC 26-V-RP 502397 + 500853

HMEC 26-V-KX 502397 + 502437

HMEC 26-BV-KP 502397 + 504030

 Single-sided round cable, 1.85 m
 XLR-5 connector
 ¼“ (6.3 mm) jack plug

(headphones)

 PJ-068 equivalent (microphone)
 8-pin Neutricon connector
 6-pin Redel connector

* The headsets can be combined with all cables (see page 17).

Part Number

026-35

026-C5

026-35-999-3211

026-35-999-3251

026-35-999-2291

026-35-999-2281

026-35-999-3111

026-35-999-3161

026-35-999-1191

026-35-999-1171

026-35-999-3811

026-35-999-3661

026-35-999-4161

026-35-999-2171

          

x x x x

x x x x

x x x x x

x x x x x

x x x x x

x x x x x

x x x x x

x x x x x

x x x x

x x x x

x x x x x x

x x x x x x

 XLR-3 connector
 Aircraft powered
 Battery powered
 Operating control I (page 8)
 Operating control II (page 9)

19

Specifications

Headphones

Transducer principle dynamic, closed
Ear coupling supra-aural
Frequency response 20–14,000 Hz
Impedance 600 Ω mono/1.200 Ω stereo
Characteristic SPL 92 dB SPL at 1 kHz, 1 mW, mono

95 dB SPL at 1 kHz, 1 V
Max. SPL 120 dB SPL at 1 kHz
Active noise compensation ≥ 18 dB (100 – 300 Hz)
THD < 1 % at 1 kHz, 95 dB SPL
Contact pressure approx. 3.6 N

Microphone incl. preamplifier

Type MKE 46
Transducer principle pre-polarized condenser

microphone,

noise-compensating
Frequency response 100–6,000 Hz
Output voltage adjustable from 17–100 mV/Pa,

80 mV/Pa -2 dB

(factory pre-set)

 800 mV -2 dB at 114 dB SPL
Terminating impedance 150–2,200 Ω
Supply voltage 8–16 V DC

20

General data

j

Temperature range operation: –15 °C to +55 °C

storage: –55 °C to +70 °C
Weight without cable approx. 210 g
Power supply for 2x 1.5 V AA alkaline battery

NoiseGard™ (IEC LR 6) or

2x 1.2 V AA rechargeable

battery (IEC LR 6)

with approx. 60 hrs operating time

or

12–35 V DC via

aircraft DC power supply system

(on suitably equipped aircraft),

max. 35 mA

Connector assignment

HMEC 26-V-KX

¼" (6.3 mm)

ack plug

12 3

Audio Hi left

1

Audio Hi right

2

Audio Lo

3

PJ-068
equivalent

12 3

not assigned

1

Microphone Hi

2

Microphone Lo

3

XLR-3 connector

13 2

NoiseGard

1
2

DC–

3

not assigned

TM

(DC+)

21

HMEC 26-CP, -V-CP, -B-CP, -BV-CP

Solder side

1

3

2

4

1

2
3

5

4
5

Audio Hi
Audio Lo / DC–
Microphone Hi
Microphone Lo
NoiseGard

TM

(DC+)

HMEC 26-NP

Solder side

1 Audio Hi
2 Audio Lo
3 not assigned
4 Microphone Lo
5 Microphone Hi
6 not assigned
7 DC–
8 NoiseGard

TM

(DC+)

HMEC 26-V-RP

Solder side

TM

1 NoiseGard

6

1

2

3

2 Audio Lo / DC–
3 Audio Hi left

5

4 Audio Hi right

4

5 Microphone Hi
6 Microphone Lo

(DC+)

22

HMEC 26-KP, -V-KP, -BV-KP, -B-K, -BV-K

1/4" (6.3 mm) jack plug PJ-068 equivalent

12 3

HMEC 26-KP

1 Audio Hi 1 NoiseGard™ (DC+)
2 not assigned 2 Microphone Hi
3 Audio Lo / DC– 3 Microphone Lo

HMEC 26-V-KP / -BV-KP

1 Audio Hi left 1 NoiseGard™ (DC+)
2 Audio Hi right 2 Microphone Hi
3 Audio Lo / DC– 3 Microphone Lo / DC–

HMEC 26-B-K

1 Audio Hi 1 not assigned
2 not assigned 2 Microphone Hi
3 Audio Lo 3 Microphone Lo

HMEC 26-BV-K

1 Audio Hi left 1 not assigned
2 Audio Hi right 2 Microphone Hi
2 Audio Lo 2 Microphone Lo

12 3

23

Manufacturer Declarations

Warranty

Sennheiser electronic GmbH & Co. KG gives a warranty of
5 years on this product.

For the current warranty conditions, please visit our web
site at www.sennheiser.com or contact your Sennheiser
partner.

CE Declaration of Conformity

This equipment is in compliance with the essen­tial requirements and other relevant provisions of
Directive 2004/108/EU. The declaration is avail-

able on the internet site at www.sennheiser.com.
Before putting the device into operation, please observe

the respective country-specific regulations!

24

Sennheiser electronic GmbH & Co. KG Printed in Germany
Am Labor 1, 30900 Wedemark, Germany Publ. 01/09
www.sennheiser.com 523983/A01