Sennheiser MP3 Player Accessories HMDC 322 User Manual

Instructions for use  
Headset  
HMEC 300  
HMEC 302  
HMEC 305  
HMEC 305-C  
HMEC 306  
HMEC 322  
HMEC 400  
HMDC 322  
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The HMEC300, HMEC302, HMEC305,HMEC305-C, HMEC306, HMEC322, HMEC400  
and HMDC322 are pilot headsetswith closed earprotectorheadphonesand NoiseGard™  
active noise compensation for use in helicopters, propeller and turboprop aircraft.  
Safety tips  
With the NoiseGard™ active noise compensation turned 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™  
turned 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.  
Do not attempt to repair the headset yourself. If problems occur, contact your  
Sennheiser agent for assistance.  
Only replace parts of the headset whose replacement is described in this manual.  
All other parts of the headset must be replaced by your Sennheiser agent.  
Do not immerse the headset in water! For information on how to clean the headset,  
contact your Sennheiser agent.  
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Headset features  
HMEC 300 NoiseGard™ headset  
New active headset with effective attenuation of external noise across the entire  
frequency spectrum due to NoiseGard™ active noise compensation  
NoiseGard™ active noise compensation provides clear communications even in the  
noisiest environment  
Excellent comfort due to very low weight, soft ear cushions and padded headband  
as well as best possible freedom of movement due to unilateral connecting cable  
Foldable headband for easy and space-saving storage  
Clear communications due to MKE 45-1 electret microphone with adjustable sensitivity  
Microphone can be easily positioned and worn on either left or right side due to  
flexible microphone boom with quick-fixing device  
Optimum radio reception due to headphone systems with wide frequency response  
Integrated volume control  
Adaption to the aircraft intercom system via Mono/Stereo switch  
With the NoiseGard™ active noise compensation turned off, the headset can be  
used as a conventional headset  
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Power supply for NoiseGard™ is provided via on-board power supply system,  
cigarette lighter socket or battery pack  
Fail safe operation in case of power failure  
Supply voltage for the NoiseGard™ system is processed by the in-line electronics in  
the connecting cable  
Made in Germany, two-year warranty  
Product variants  
HMEC 302 NoiseGard™ headset  
The HMEC 302 differs from the HMEC 300 in the following features:  
Connection of microphone and NoiseGard™ electronics via PJ-068 plug  
HMEC 305 NoiseGard™ headset  
The HMEC 305 differs from the HMEC 300 in the following features:  
No Mono/Stereo switch  
Connection of headphones, microphone and NoiseGard™ electronics to the on-board  
power supply system (12–35 V DC) via XLR-5 plug  
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HMEC 305-C NoiseGard™ headset  
The HMEC 305-C differs from the HMEC 300 in the following features:  
No Mono/Stereo switch  
Connection of headphones and microphone via XLR-5 plug  
HMEC 306 NoiseGard™ headset  
The HMEC 306 differs from the HMEC 300 in the following features:  
Connection of headphones, microphone and NoiseGard™ electronics to the on-board  
power supply system (12–35V DC) via 6-pin Redel plug  
HMEC 322 NoiseGard™ headset  
The HMEC 322 differs from the HMEC 300 in the following features:  
No Mono/Stereo switch  
Coiled cable  
Connection of headphones and microphone via U-174/U jack plug to a high impedance  
interface in the helicopter  
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HMEC 400 NoiseGard™ headset  
The HMEC 400 differs from the HMEC 300 in the following features:  
Stylish silver design  
Leatherette ear cushions  
Headband padding can be buttoned  
HMDC 322 NoiseGard™ headset  
The HMDC 322 differs from the HMEC 300 in the following features:  
No Mono/Stereo switch  
Coiled cable  
M-87/AIC dynamic microphone and low impedance headphones  
Connection of headphones and microphone via U-174/U jack plug to a low impedance  
interface in the helicopter  
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Delivery includes  
HMEC 300, HMEC 305-C, HMEC 322, HMEC 400 and HMDC 322 headsets  
Headset  
3-pin XLR socket for aircraft panel mounting (power supply via the on-board system)  
Padded carry and storage bag with shoulder strap for headset and accessories  
Wind screen for microphone (except HMDC 322)  
MZQ 2002-1 Cable clip (Cat. No. 44740)  
HMEC 302, HMEC 305 and HMEC 306 headsets  
Headset  
Padded carry and storage bag with shoulder strap for headset and accessories  
Wind screen for microphone  
MZQ 2002-1 Cable clip (Cat. No. 44740)  
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Recommended accessories  
Replaceable gel ear cushions (Cat. No. 83140)  
BP-03 battery pack (except for HMEC 302, HMEC 305 and HMEC 306)  
Battery pack with XLR-3 socket for powering the NoiseGard™ electronics of the HMEC 300,  
HMEC 305-C, HMEC 322, HMEC 400 and HMDC 322 headsets. Four 1.5 V AA size  
alkaline manganese batteries (IEC LR 6) ensure approx. 15 hours of reliable operation  
(batteries are not included in the delivery). Length of connecting cable: 0.9 m.  
Adapter cables (except for HMEC 302, HMEC 305 and HMEC 306)  
Sennheiseroffersspecialadaptercablesforconnecting the NoiseGardelectronicsofthe  
HMEC 300, HMEC 305-C, HMEC 322, HMEC 400 and HMDC 322 headsets to the on-  
board power supply via the cigarette lighter socket:  
ACX-1  
ACX-2  
ACX-1 adapter cable for powering one headset via the cigarette lighter socket  
ACX-2 adapter cable for powering two headsets via the cigarette lighter socket  
The adapter cables are also available with a right-angled jack plug featuring a 7.5 A fuse  
and a green LED operation indicator:  
ACX-11 adapter cable for powering one headset via the cigarette lighter socket  
ACX-11  
ACX-22  
ACX-22 adapter cable for powering two headsets via the cigarette lighter socket  
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Connecting the headsets  
Connecting cables for headsets  
HMEC 300 and HMEC 400 headsets:  
1
1/4” (6.35 mm) stereo jack plug for connecting the headphones  
1 PJ-068 jack plug for connecting the microphone  
1 XLR-3 plug for connecting the power supply for the NoiseGard™ electronics  
Connecting cable for  
HMEC 300 and HMEC 400  
HMEC 302 headset:  
1 /4” (6.35 mm) stereo jack plug for connecting the headphones  
1 PJ-068 jack plug for connecting the microphone and the power supply for the  
NoiseGard™ electronics  
Connecting cable for  
HMEC 302  
HMEC 305 headset:  
1 XLR-5 plug for connecting the headphones, the microphone and the power supply for  
the NoiseGard™ electronics  
Connecting cable for  
HMEC 305  
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HMEC 305-C headset:  
1 XLR-5 plug for connecting the headphones and the microphone  
1 XLR-3 plug for connecting the power supply for the NoiseGard™ electronics  
Connecting cable for  
HMEC 305-C  
HMEC 306 headset:  
1 6-pin Redel plug for connecting the headphones, the microphone and the power  
supply for the NoiseGard™ electronics  
Connecting cable for  
HMEC 306  
HMEC 322 and HMDC 322 headsets:  
1 U-174/U jack plug for connecting the headphones and the microphone  
1 XLR-3 plug for connecting the power supply for the NoiseGard™ electronics  
Connecting cable for  
HMEC 322 and HMDC 322  
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Powering options  
There are three options for powering the NoiseGard™ active noise compensation:  
1. Connection to the on-board system (12–35 V DC)  
2. Connection to the BP-03 battery pack  
(accessory, except for HMEC 302, HMEC 305 and HMEC 306)  
3. Connection to the cigarette ligther socket (12–35 V DC) via adapter cable  
(accessory, except for HMEC 302, HMEC 305 and HMEC 306)  
The supply voltage for the NoiseGard™ system is processed by the in-line electronics in  
the connecting cable.  
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1. Connecting the headset to the on-board system  
The NoiseGard™ electronics can be connected to on-board power supply systems with  
operating voltages between 12–35 V DC.  
Danger of short circuit!  
Before turning on NoiseGard™, ensure that the on-board power supply system is  
protected by a 1 A fuse.  
Power supply for  
NoiseGard™  
The HMEC 300, HMEC 305-C, HMEC 322, HMEC 400 and HMDC 322 headsets are  
supplied with an XLR-3 socket for panel mounting in the aircraft. The XLR-3 socket must  
be mounted by a technician qualified to perform this type of installation.  
Ground  
Do not connect!  
XLR-3 socket for HMEC 300, HMEC 305-C,  
HMEC 322, HMEC 400 and HMDC 322  
headsets  
HMEC 300 and HMEC 400 headsets:  
Ǡ
Connect the 1/4” (6.35 mm) stereo jack plug for the headphones and the PJ-068 jack  
plug for the microphone to the corresponding jack sockets of your intercom.  
Ǡ
Connect the XLR-3 plug to the XLR-3 socket.  
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Headset HMEC 302:  
Ǡ
Connect the 1/4” (6.35 mm) stereo jack plug for the headphones and the PJ-068 jack  
plug for the microphone to the corresponding jack sockets of your intercom.  
HMEC 305 headset:  
Connect the XLR-5 plug to the aircraft’s XLR-5 socket.  
Ǡ
Headset HMEC 305-C:  
Ǡ
Connect the XLR-5 plug for the headphones and the microphone to the aircraft’s  
XLR-5 socket.  
Ǡ
Connect the XLR-3 plug to the XLR-3 socket.  
HMEC 306 headset:  
Connect the 6-pin Redel plug to the corresponding socket in the aircraft.  
Ǡ
HMEC 322 and HMDC 322 headsets:  
Ǡ
Connect the U-174/U jack plug for the headphones and the microphone to the  
U-174/U socket of your intercom.  
Ǡ
Connect the XLR-3 plug to the XLR-3 socket.  
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2. Connecting the headset to the battery pack  
(except HMEC 302, HMEC 305 and HMEC 306)  
The NoiseGard™ electronics of the HMEC 300, HMEC 305-C, HMEC 322, HMEC 400 and  
HMDC 322 headsets can also be powered via the BP-03 battery pack (‘Recommended  
accessories’). The battery pack can be operated either on standard or rechargeable  
batteries (not included in the delivery). However, to ensure a longer operating time, we  
would recommend using standard AA size alkaline manganese batteries (IEC LR6). If  
operated on rechargeable batteries, the operating time will be reduced to approx. 3  
hours.  
Inserting / replacing the the batteries  
Ǡ
Ǡ
Open the cover of the battery compartment.  
Insert four AA size alkaline-manganese batteries (IEC LR6). Observe correct polarity  
when inserting the batteries.  
Ǡ
Close the cover of the battery compartment.  
LED operation and battery status indication  
The battery pack has two control LEDs.  
Green LED:  
Red LED:  
The battery pack is turned on and the battery capacity is sufficient.  
The batteries are low. Replace the batteries.  
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Connecting the headset, turning on the battery pack  
Ǡ
Connect the XLR-3 plug of the headset connecting cable to the XLR-3 socket on the  
connecting cable of the battery pack.  
Ǡ
HMEC 300 and HMEC 400 headsets: Connect the 1/4” (6.35 mm) stereo jack plug  
forthe headphonesand the PJ-068 jackplug forthe microphone to the corresponding  
jack sockets of your intercom.  
HMEC 305-C headset: Connect the XLR-5 plug for the headphones and the  
microphone to the aircraft’s XLR-5 socket.  
HMEC 322 and HMDC 322 headsets: Connect the U-174/U jack plug for the  
headphones and the microphone to the U-174/U socket of your intercom.  
Ǡ
Turn on the battery pack by setting the ON/OFF switch to ON. The green LED power  
indicator lights up.  
Note:  
When using the battery pack, the ON/OFF switch integrated into the headset  
connecting cable is out of operation.  
Attaching the battery pack to clothing  
The battery pack can be attached to clothing by means of the supplied attachment clip,  
Velcro tape is also supplied.  
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3. Connecting the headset via a cigarette lighter adapter cable  
(except HMEC 302, HMEC 305 and HMEC 306)  
Sennheiseroffersspecialadaptercableswith XLR-3 socket forconnecting the NoiseGard™  
electronics of the HMEC 300, HMEC 305-C, HMEC 322, HMEC 400 and HMDC 322  
headsets to the on-board power supply via the cigarette lighter socket:  
ACX-1 adapter cable for powering one headset via the cigarette lighter socket  
ACX-2 adapter cable for powering two headsets via the cigarette lighter socket  
ACX-1  
ACX-2  
The adapter cables are also available with a right-angled jack plug featuring a 7.5 A fuse  
and a green LED operation indicator:  
ACX-11 adapter cable for powering one headset via the cigarette lighter socket  
ACX-22 adapter cable for powering two headsets via the cigarette lighter socket  
ACX-11  
ACX-22  
Connecting the headset  
Ǡ
Connect the XLR-3 plug of the headset connecting cable to the XLR-3 socket of the  
adapter cable.  
Ǡ
Connect the plug or right-angled jack plug ofthe adaptercable to the cigarette lighter  
socket.  
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Preparing the headsets for use  
Adjusting the headband  
For good noise attenuation and best possible comfort, the headband has to be adjusted  
to properly fit your head:  
Ǡ
Ǡ
Wear the headset so that the headband runs over the top of your head.  
Adjust the length of the headband so that  
your ears are completely inside the ear cushions,  
you feel even, gentle pressure around your ears,  
a snug fit is ensured.  
Note:  
Make sure not to squeeze any connecting cable when adjusting the headband.  
Squeezing can damage the connecting cables.  
Ǡ
Ǡ
Turn on the NoiseGard™ active noise compensation by setting the ON/OFF switch  
to ON (Turning NoiseGard™ on/off”).  
Final adjustment is best made in a noisy environment.  
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Positioning the microphone  
Relocating the microphone boom  
The microphone boom can be worn on either side of the mouth.  
Ǡ
Ǡ
Ǡ
Loosen the quick-fixing device.  
Rotate the microphone boom by 180°.  
Tighten the quick-fixing device.  
Positioning the microphone towards the corner of the mouth  
The HMEC 300, HMEC 302, HMEC 305, HMEC 305-C, HMEC 306, HMEC 322 and  
HMEC 400 headsets feature a flexible microphone boom. Bend the 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.  
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For positioning the microphone of the HMDC 322 headset, proceed as follows:  
Ǡ
Adjust the length of the microphone boom so that the microphone is placed at the  
corner of the mouth. To do so, loosen the quick-fixing device and adjust the  
microphone boom in length.  
Ǡ
Ǡ
Pull the middle part of the microphone boom towards the mouth so that the  
distance between microphone and mouth is approx. 2 cm.  
Tilt the microphone for final positioning.  
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Additional information for helicopter use of the HMEC 322 headset  
The polarity of the microphone connection in helicopters is not standardized. If the  
microphone of your headset does not work with the existing polarity, you can reverse the  
polarity on the headset by simply rotating the microphone module. To do so, please  
proceed as follows:  
1. Pull the wind screen from the microphone.  
2. Loosen the screws by approx. half a turn.  
3. Pull the microphone module from the boom-arm.  
4. Rotate the microphone module by 180°.  
5. Put the rotated microphone module back into the boom-arm.  
6. Now tighten the screws from the other side.  
7. Slide the windscreen over the microphone.  
Rotating the microphone module does not change its acoustic properties. Due to its noise-  
compensating pick-up pattern, the microphone can be used from either side.  
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Using the headsets  
Turning NoiseGard™ on/off  
With the NoiseGard™ active noise compensation turned off, the headset can be used as  
a conventional headset.  
Turn on the NoiseGard™ active noise compensation by setting the ON/OFF switch to ON.  
When using the BP-03 battery pack, set the NoiseGard™ ON/OFF switch to ON and use  
the ON/OFF switch on the battery pack.  
Mono/Stereo selection (except HMEC 305, HMEC 305-C, HMEC 322 and  
HMDC 322)  
In general, youll receive a mono sound source so that the Mono/Stereo switch can remain  
set to “Mono”. When using a stereo intercom system, set the Mono/Stereo switch to  
Stereo”.  
Adjusting the volume  
Exposure to loud sounds can cause hearing damage!  
Set the volume control to a medium value. Make sure that you can hear critical sounds  
such as warning alarms.  
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Mic Gain Adjustment  
Adjusting the microphone gain  
According to JTSO approval C58a, the microphone output voltage has to be factory-  
preset to 400 mV. If this output voltage is too high or too low for your intercom system,  
it can easily be re-adjusted on the microphone. To do so, use a small slotted screwdriver  
and turn the ”Mic Gain Adjustment” screw (see illustration on the left) until you reach the  
desired setting.  
Attaching the cable clip  
The headphone cable can be fixed by means of the cable clip. Guide the headphone cable  
through the metal cable clip as shown in the illustration on the left. Attach the cable clip  
to your clothing and then loop the cable through the clip so that the headphone cable  
doesnt disturb you.  
Folding up the headphones  
For easy and space-saving transportation, the earcups can be folded up and tucked  
between the headband.  
Unfold the headphones by grasping both earcups and pulling them down and away from  
the headband.  
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Spare parts  
The following spare parts are available from your Sennheiser agent:  
Wind screen for MKE 45-1 electret microphone  
Ear cushions  
Headband padding  
Cable clip  
Carry and storage bag with shoulder strap  
Replacing the wind screen  
If the wind screen for the electret microphone shows signs of wear such as tears or holes,  
replace the wind screen. Pull the wind screen from the microphone. Gently slide-on the  
new wind screen and ensure that it fits securely over the microphone.  
Replacing the ear cushions  
Replace the ear cushions if they are damaged. Grasp behind the ear cushions and pull  
them up and away from the earcups. Slide the new ear cushions onto the earcups.  
For best results replace the ear cushions after 100 hours of use or two years.  
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Replacing the headband padding  
Replace the headband padding if it is damaged.  
Ǡ
Pull the Ziploc type fastening strips of the headband padding apart and remove the  
worn headband padding.  
Ǡ
Ǡ
Put the new headband padding around the headband.  
Pull the two edges of the headband padding together so that the fastening strips  
slightly overlap.  
Ǡ
Join the fastening strips.  
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In case of difficulty  
If problems occur that are not listed in the below table, please contact your Sennheiser  
agent.  
Problem  
Possible cause and what to do  
Clear communication but no  
active noise compensation  
The NoiseGard™ electronics are turned off.  
Ǡ
Check to see if the ON/OFF switch is set to ON.  
The XLR-3 plug has been pulled out of the power source.  
Check to see if the XLR-3 plug is correctly connected to the power source.  
If aircraft powered: The aircraft fuse is defective.  
Check the aircraft fuse.  
If battery powered (except HMEC 302, HMEC 305 and HMEC 306): The batteries are low.  
Ǡ
Ǡ
Ǡ
Check to see if the green LED on the battery pack is lit. If the red LED is lit, replace  
the batteries.  
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Problem  
Possible cause and what to do  
Active noise compensation but  
very low volume communication  
The volume control is set too low.  
Ǡ
Check the volume setting of the headset.  
The headphone connection has been pulled out (except HMEC 305, HMEC 305-C and  
HMEC 306).  
Ǡ
Check to see if the headphone jack plug is correctly connected.  
Active noise compensation but  
reduced intelligibility  
The microphone connection has been pulled out (except HMEC 305, HMEC 305-C and  
HMEC 306).  
Ǡ
Check to see if the microphone jack plug is correctly connected.  
You are using a stereo intercom system but the headset is set to mono operation.  
Set the Mono/Stereo switch to Stereo.  
You are receiving a mono source but the headset is set to stereo operation.  
Set the Mono/Stereo switch to Mono’.  
Communications in one ear only  
(only HMEC 300, HMEC 302,  
HMEC 306 and HMEC 306)  
Ǡ
Ǡ
Re-adjust the output voltage on the microphone.  
Microphone output voltage set  
too high or too low  
Ǡ
To do so, use a small slotted screwdriver and turn the “Mic Gain Adjustment” screw  
(see illustration on page 133) until you reach the desired setting.  
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Valuable information on NoiseGard™  
The NoiseGard™ principle  
One of the greatest stress factors today is noise. Research has shown that noise affects  
the nervous system, and can cause tiredness, poor concentration, irritability and tension.  
Of even greater concern is the permanent damage to hearing that can result from noise  
at high levels.  
This problem concerns pilots in particular. Cockpit noise amounts to about 80 dB(A) in jets  
and to 90 up to 97 dB(A) in turboprops. During takeoff and landing, the noise level is even  
higher. To be able to understand radio traffic in spite of the noisy environment, the ATC  
signal level must be set to at least 95 dB(A). Permanent hearing loss caused by the  
continuous noise in aircrafts is the reason why many pilots became prematurely disabled  
or lost their pilot´s license.  
Circumaural communication headsets provide noise attenuating properties and are  
commonly used to address this problem. However, the noise attenuation of these  
headsets is uneven. High frequencies are reduced considerably, but low frequency wind  
and engine noise, the most prominent noise in manyoftoday'saircrafts, isattenuated very  
little.  
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In response to these problems, Sennheiser has developed an active noise compensation  
system – NoiseGard™ – which, combined with a high-quality passive hearing protector,  
provides consistent noise attenuation over the entire audio range. The overall noise level  
is reduced so that the radio volume can be turned down but enough noise still remains  
for the pilot to safely monitor the aircraft engines.  
A
NoiseGard™ active noise compensation is achieved by generating a signal identical in  
sound pressure level but exactly reversed in phase to the noise signal, the effect being that  
the out-of-phase signal cancels most of the noise signal.  
Active noise compensation isaccomplished in the following manner:Each earcup includes  
a microphone, a feedback control circuit, and a transducer to reproduce both the  
communication and the noise cancelling signal. The feedback control microphones sense  
the total sound pressure within each earcup resulting from both the desired radio signal  
from the receiver and the undesired noise that has come through the earcup. The  
microphone signal is amplified and the radio signal is subtracted from it. The remaining  
signal (noise) is then filtered and inverted and the radio signal is added back in. Eventually,  
the entire signal is amplified and fed back to the transducer in each earcup. Since the noise  
component ofthe signalisinverted, it cancelsthe noise signalcoming through the earcup.  
The radio signal remains unaffected, as it was not processed through the cancellation  
circuits.  
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The above diagram shows noise compensation with NoiseGard™: Passive hearing  
protectors effectively attenuate noise from the middle and upper frequency range, the  
effect decreasing sharply in the lower range. However, active noise compensation with  
NoiseGard™ combined with passive hearing protectors results in a reduction of noise of  
approx. 25 dB in the 25–500 Hz frequency range. The total attenuation resulting from  
active and passive noise compensation is about 30 dB over the entire audio range.  
A 10 dB reduction in noise is perceived subjectively as a halving in volume. A further  
reduction in noise of 10 dB again results in a decrease in unwanted noise by 50 % .  
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Connector assignment  
6
3
2
4
1
5
solder side  
XLR-5 connector  
Redel connector (NoiseGard™)  
XLR-3 connector (NoiseGard™)  
HMEC 305  
HMEC 305-C  
1 PowersupplyNoiseGard(DC+) 1 Power supply NoiseGard™ (DC+) 1 Audio Hi  
1 Audio Hi  
2 Audio Lo / DC –  
3 Audio Hi left  
4 Audio Hi right  
5 Microphone Hi  
6 Microphone Lo  
2 Ground  
3 Do not connect!  
2 Audio Lo / DC –  
3 Microphone Hi  
4 Microphone Lo  
2 Audio Lo  
3 Microphone Hi  
4 Microphone Lo  
5 Power supply NoiseGard™ (DC+) 5 Not assigned!  
1
2
3
1
2
3
1
2 3  
4
1/4” (6.35 mm) stereo jack plug  
U174/U jack plug  
PJ-068 jack plug  
HMEC 302  
HMEC 300  
1 Audio Hi left  
2 Audio Hi right  
3 Audio Lo  
1 Microphone Lo  
2 Audio Hi  
3 Microphone Hi  
4 Audio Lo  
1 PowersupplyNoiseGard(DC+) 1 Not assigned!  
2 Microphone Hi  
3 Microphone Lo / DC –  
2 Microphone Hi  
3 Microphone Lo  
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Technical data  
HMEC 300  
HMEC 302  
HMEC 306  
HMEC 400  
Headphones  
Transducer principle  
dynamic  
Ear coupling  
Frequency response  
Nominal impedance active/passive  
circumaural, closed  
45–15,000 Hz  
300/150 , mono  
600/300 , stereo  
> 25 – 40 dB  
Attenuation (active and passive)  
Max. sound pressure level  
Contact pressure  
120 dB (± 5% )  
approx. 10 N  
Microphone incl. preamplifier  
Transducer principle  
Frequency response  
Sensitivity  
electret mic capsule, noise-compensated, MKE 45-1  
300–5,000 Hz  
Max. sound pressure level  
Min. terminating impedance  
Output voltage  
120 dB  
150 Ω  
400 mV ± 3 dB at 114 dB (as per RTCA/DO 214)  
Supply voltage  
typ. 16 V DC (8 – 16 V DC, approx. 8 – 25 mA, as per RTCA/DO 214)  
142  
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HMEC 300  
HMEC 302  
HMEC 306  
HMEC 400  
General data  
Connecting cable  
Weight without cable  
Power supply for NoiseGard™  
Current consumption  
Fuse  
1.5 m, unilateral  
370 g  
12–35 V DC  
27 mA (zero signal current), max. 80 mA  
500 mA thermo fuse  
Connectors  
6.35 mm stereo jack plug 6.35 mm stereo jack plug 6-pin Redel plug for  
6.35 mm stereo jack plug  
for headphones,  
PJ-068 jack plug for  
mirophone,  
XLR-3 for NoiseGard™  
Mono/Stereo switch  
for headphones,  
PJ-068 jack plug for  
microphone and  
NoiseGard™  
headphones, microphone for headphones,  
and NoiseGard™  
PJ-068 jack plug for  
mirophone,  
XLR-3 for NoiseGard™  
Controls  
On/off switch for NoiseGard™  
Volume control for headphones  
Temperature range  
Operation  
Storage  
–15°C ... + 55°C  
–55°C ... + 55°C  
Operating time Battery pack  
with batteries (four 1.5 V AA size alkaline-manganese batteries): approx. 15 hours  
with rechargeable batteries: approx. 3 hours  
143  
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Technical data  
HMEC 305  
ȊHMEC 305-C  
ȊHMEC 322  
ȊHMDC 322  
Headphones  
Transducer principle  
dynamic  
Ear coupling  
Frequency response  
Nominal impedance active/passive  
Attenuation (active and passive)  
Max. sound pressure level  
Contact pressure  
circumaural, closed  
45–15,000 Hz  
300/150 , mono  
> 25 – 40 dB  
120 dB (± 5% )  
approx. 10 N  
Ȋ 50/35 , mono  
Microphone incl. preamplifier  
Transducer principle  
electret mic capsule,  
noise-compensated,  
MKE 45-1  
Ȋ dynamic mic capsule,  
Ȋ noise-compensated,  
Ȋ M-87/AIC  
Frequency response  
Sensitivity  
300–5,000 Hz  
Ȋ 500–4,000 Hz  
Ȋ 1.8–4 µV / 74 dB at 5 Ω  
Max. sound pressure level  
Min. terminating impedance  
Output voltage  
120 dB  
150 Ω  
Ȋ –  
Ȋ –  
Ȋ –  
Ȋ –  
400 mV ± 3 dB at 114 dB (as per RTCA/DO 214)  
typ. 16 V DC (8 – 16 V DC, approx. 8 – 25 mA, as per RTCA/DO 214)  
Supply voltage  
144  
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HMEC 305  
ȊHMEC 305-C  
ȊHMEC 322  
ȊHMDC 322  
General data  
Connecting cable  
Weight without cable  
Power supply for NoiseGard™  
Current consumption  
Fuse  
1.5 m, unilateral  
370 g  
12–35 V DC  
27 mA (zero signal current), max. 80 mA  
500 mA thermo fuse  
Ȋ coiled cable, unilateral  
Connectors  
XLR-5 for headphones,  
microphone and  
NoiseGard™  
Ȋ XLR-5 for headphones Ȋ U-174/U jack plug for headphones and microphone,  
Ȋ and microphone.  
Ȋ XLR-3 for NoiseGard™  
Ȋ XLR-3 for NoiseGard™  
Ȋ
Controls  
On/off switch for NoiseGard™  
Volume control for headphones  
Temperature range  
Operating time Battery pack  
Operation  
Storage  
–15°C ... + 55°C  
–55°C ... + 55°C  
with batteries (four 1.5 V AA size alkaline-manganese batteries): approx. 15 hours  
with rechargeable batteries: approx. 3 hours  
145  
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Certificate of Conformity  
Sennheiser electronic GmbH & Co. KG declare that this device conforms to the applicable CE standards and regulations.  
Forup-to-date information on Sennheiserproducts, you can also visit the SennheiserWeb site at http://www.sennheiser.com.  
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