Sennheiser HMEC 250 - 05-10 User manual

HMEC 250
Headset for
general aviation
Instruction manual

1
Contents
Important safety instructions ...................................................2
Delivery includes ..........................................................................4
The HMEC 250 headset ...............................................................5
Operating elements .....................................................................7
Putting the headset into operation .........................................8
Inserting the batteries .......................................................... 8
Connecting the headset ........................................................ 8
Connecting a mobile telephone .......................................... 9
Connecting an additional audio player ........................... 10
Adjusting the microphone sensitivity ............................ 11
Switching between mono and stereo mode .................. 11
Using the headset .................................................................... 12
Attaching the cable clip ..................................................... 12
Adjusting the headset ....................................................... 12
Adjusting the microphone boom ..................................... 13
Adjusting the volume ........................................................ 13
Switching the TalkThrough function on/off .................. 14
Adjusting the volume of the TalkThrough function .... 14
Switching NoiseGard on/off ............................................. 15
Replacing the batteries ..................................................... 16
Folding up the headset ............................................................ 17
Care and maintenance ............................................................. 18
Replacing the ear pads ...................................................... 18
Replacing the wind shield ................................................. 19
Specifications ............................................................................ 20
Manufacturer declarations ..................................................... 22

2
Important safety instructions
• Please read this instruction manual carefully and
completely before using the headset.
• Make these this instruction manual easily accessible to all
users at all times.
Always include this instruction manual when passing the
headset on to third parties.
• During flight operation, do not use the headset for
telephone calls.
• 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 critical sounds,
especially warning alarms and sounds resulting from
malfunction.
• 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.
• Never repair or attempt to repair a defective headset
yourself. Contact your Sennheiser partner or the
Sennheiser Service Department.
• Only replace those parts of the headset whose
replacement is described in this instruction manual. All
other parts of the headset must be replaced by your
Sennheiser partner.
• Protect the headset from wetness. Use only a slightly
damp cloth to clean the headset. For information on how
to clean the headset, contact your Sennheiser partner.

3
Safety instructions for batteries
If abused or misused, batteries may leak and, in extreme
cases, may even present an explosion and fire hazard.
Sennheiser does not accept any liability for damage arising
from abuse or misuse.
Keep batteries out of
reach of children.
Observe correct
polarity.
Do not heat or
throw into fire.
Switch off battery
powered devices when
not in use.
Remove batteries
when the device
is not used for
extended periods
of time.
Dispose of exhausted
batteries at special
collection points or
return them to your
specialist dealer.
Do not solder. Do not short-circuit.
Do not mutilate or
dismantle.
Do not attempt
to recharge
non-rechargeable
batteries.
Do not pack charged
batteries loose –
danger of shorting
out – fire hazard.
Always remove flat or
exhausted batteries
from the device
immediately.
Do not mix old or
used batteries with
new ones. Do not
mix batteries of
different types
or brands.

4
Intended use of the headset
Intended use includes:
• having read this instruction manual, especially the
chapter “Important safety instructions” on page 2,
• using the headset within the operating conditions and
limitations described in this instruction manual.
“Improper use” means using the headset other than as
described in this instruction manual, or under operating
conditions which differ from those described herein.
Delivery includes
Delivery of the HMEC 250 headset includes:
1 HMEC 250 headset
1softcase
1 HZC 08 cable clip
2 Wind and pop shields for MZW 46
1 audio-in cable for mobile telephones, length 0.6 m,
with two 2.5 mm jack plugs
1 audio-in cable for additional audio players, length 0.6 m,
with two 3.5 mm jack plugs
2 AAA size batteries
1 instruction manual

5
The HMEC 250 headset
The HMEC 250 headset with NoiseGard 2.0 active noise
compensation features closed, dynamic, circumaural stereo
headphones. The HMEC 250 is a headset for general aviation
use.
NoiseGard 2.0TM
The NoiseGard 2.0 active noise compensation system is
based on the principle of cancelling out sound using “anti-
sound” (phase-inverted sound). Tiny microphones pick up
low-frequency ambient noise (up to 1 kHz) near the ear. The
NoiseGard 2.0 electronics use this noise to generate a sound
wave which is the exact opposite (i.e.: at the same level but
polarity reversed – 180° out-of-phase), the result is that the
polarity reversed signal cancels most of the outside noise.
Fail safe operation
When the batteries are completely discharged, NoiseGard
automatically switches off. RT traffic (e.g. ATC) and
intercom will still be heard through the headphones.
Peak level protection
The peak level protection safeguards your ears from volume
peaks above 110 dB.
TalkThrough function (TT)
The TalkThrough function allows you to communicate with
the people around you while wearing the headset. The
NoiseGard active noise compensation and the peak level
protection remain unaffected by the TalkThrough function
and help to protect your hearing.

6
Additional features
• Outstanding transmission quality for clear communi-
cations
• Good passive attenuation of ambient noise
• Foldable design for space-saving storage and transpor-
tation
• Noise-compensating boom microphone ensures excellent
speech transmission
• Flexible microphone boom
• Separate left and right channel volume control
•Excellentcomfortresultingfrom soft ear pads and head-
band padding
• Audio-input facility for external audio sources, such as
mobile phones, MP3 players

7
Operating elements
Headset
Microphone sensitivity control
Headset cable
Microphone boom
Ear pads, ergonomic
Headband
Battery compartment (on both sides)
Operating control integrated
in the headset
TT VOLUME + button (Talk Through)
ON/OFF button (NoiseGard)
TT VOLUME – button (Talk Through)
TALK THROUGH button (on/off)
LED (status display)
Operating control integrated in the cable
Cable with microphone plug,
5.25 mm jack plug
Cable with headphone plug,
¼” (6.35 mm) jack plug
3.5 mm jack socket for connecting an
additional audio player (3-pin)
2.5 mm jack socket for connecting a
mobile telephone (3-pin)
Mono/stereo switch
Separate left and right channel
slide volume controls



쐋








햴




8
LED indications
Meanings of the LED :
Putting the headset into operation
Inserting the batteries
Insert the batteries into the battery compartments on the
left and right ear cups as follows:
왘Open the battery compartment by pushing the catch
and open the cover.
왘Insert the AAA size battery as shown.
왘Close the battery compartment . The battery compart-
ment cover locks into place with an audible click.
Connecting the headset
The headset’s operating control features two cables with
one jack plug each.
왘Connect the headset to the corresponding sockets of your
intercom.

LED Meaning
red NoiseGard is switched on
green TalkThrough is switched on
flashing Batteries are almost flat


Connector for connection to the
¼” (6.35 mm) jack plug headphone output
5.25 mm jack plug microphone input

9
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 intercom.
Asuitable adapter for your mobile telephone with 2.5 mm
jack socket is available from your specialist dealer.
왘Connect the audio cable to the 2.5 mm jack socket (3-pin)
on the operating control and to the corresponding jack
socket on your mobile telephone (4-pin).
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.
왘Switch NoiseGard on (see “Switching NoiseGard on/off”
on page 15).
Audio from the mobile telephone and from the intercom
are heard simultaneously through the headset.
왘Operate your mobile telephone as usual and observe the
manufacturers instructions.


DANGER! Danger of accident due to reduced
attention!
Making telephone calls or operating the
mobile telephone limits your attention and
may cause accidents.
왘During flight operation, do not use the
headset for telephone calls!
For the latest list of compatible mobile telephones,
please refer to the „Professional Audio“ >
„Aviation Headsets“ section on our website at
www.sennheiser.com.
