Instructions for use Headset HMEC 300 HMEC 302 HMEC 305 HMEC 305-C HMEC 306 HMEC 322 HMEC 400 HMDC 322 ™ 111
Contents Safety tips .................................................................................................... 113 Headset features .............................................................................................. 114 Product variants ........................................................................................................................ 115 Delivery includes ..............................................................................................
The HMEC 300, HMEC 302, HMEC 305,HMEC 305-C, HMEC 306, HMEC 322, HMEC 400 and HMDC 322 are pilot headsets with closed ear protector headphones and 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.
Headset features HMEC 300 NoiseGard™ headset • • • • • • • • • • 114 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
• • • • 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™ h
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/
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 117
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.
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.
Connecting the headsets Connecting cables for headsets Connecting cable for HMEC 300 and HMEC 400 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 HMEC 302 headset: Connecting cable for HMEC 302 Connecting cable for HMEC 305 120 1 /4” (6.
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
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.
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.
Headset HMEC 302: 씰 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: 씰 Connect the XLR-5 plug to the aircraft’s XLR-5 socket. Headset HMEC 305-C: 씰 Connect the XLR-5 plug for the headphones and the microphone to the aircraft’s XLR-5 socket. 씰 Connect the XLR-3 plug to the XLR-3 socket. HMEC 306 headset: 씰 Connect the 6-pin Redel plug to the corresponding socket in the aircraft.
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).
Connecting the headset, turning on the battery pack 씰 씰 Connect the XLR-3 plug of the headset connecting cable to the XLR-3 socket on the connecting cable of the battery pack. HMEC 300 and HMEC 400 headsets: 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-C headset: Connect the XLR-5 plug for the headphones and the microphone to the aircraft’s XLR-5 socket.
3.
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: 씰 Wear the headset so that the headband runs over the top of your head. 씰 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.
Positioning the microphone Relocating the microphone boom The microphone boom can be worn on either side of the mouth. 씰 Loosen the quick-fixing device. 씰 Rotate the microphone boom by 180°. 씰 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.
For positioning the microphone of the HMDC 322 headset, proceed as follows: 씰 씰 씰 130 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. 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.
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.
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.
Mic Gain Adjustment Adjusting the microphone gain According to JTSO approval C58a, the microphone output voltage has to be factorypreset 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.
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 headband padding Replace the headband padding if it is damaged. 씰 Pull the Ziploc type fastening strips of the headband padding apart and remove the worn headband padding. 씰 Put the new headband padding around the headband. 씰 Pull the two edges of the headband padding together so that the fastening strips slightly overlap. 씰 Join the fastening strips.
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. 씰 Check to see if the ON/OFF switch is set to ON. The XLR-3 plug has been pulled out of the power source. 씰 Check to see if the XLR-3 plug is correctly connected to the power source. If aircraft powered: The aircraft fuse is defective.
Problem Possible cause and what to do Active noise compensation but very low volume communication The volume control is set too low. 씰 Check the volume setting of the headset. The headphone connection has been pulled out (except HMEC 305, HMEC 305-C and HMEC 306). 씰 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).
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.
A 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.
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.
Connector assignment 6 2 1 3 4 5 solder side XLR-5 connector Redel connector (NoiseGard™) 1 2 3 4 5 6 XLR-3 connector (NoiseGard™) Power supply NoiseGard™ (DC+) 1 Power supply NoiseGard™ (DC+) Audio Lo / DC – 2 Ground Audio Hi left 3 Do not connect! Audio Hi right Microphone Hi Microphone Lo ; HMEC 305 HMEC 305-C 1 2 3 4 5 1 2 3 4 5 Audio Hi Audio Lo / DC – Microphone Hi Microphone Lo Power supply NoiseGard™ (DC+) Audio Hi Audio Lo Microphone Hi Microphone Lo Not assigned! ;;;;;;;;;;;;; ;;;;;;;;
Technical data HMEC 300 HMEC 302 HMEC 306 Headphones Transducer principle Ear coupling Frequency response Nominal impedance active/passive Attenuation (active and passive) Max. sound pressure level Contact pressure dynamic circumaural, closed 45–15,000 Hz 300/150 Ω, mono 600/300 Ω, stereo > 25 – 40 dB 120 dB (± 5%) approx. 10 N Microphone incl. preamplifier Transducer principle Frequency response Sensitivity Max. sound pressure level Min.
HMEC 300 HMEC 302 HMEC 306 HMEC 400 General data Connecting cable Weight without cable Power supply for NoiseGard™ Current consumption Fuse Connectors Controls Temperature range Operating time Battery pack 1.5 m, unilateral 370 g 12–35 V DC 27 mA (zero signal current), max. 80 mA 500 mA thermo fuse 6.35 mm stereo jack plug 6.
Technical data HMEC 305 앚HMEC 305-C 앚HMEC 322 앚HMDC 322 Headphones Transducer principle Ear coupling Frequency response Nominal impedance active/passive Attenuation (active and passive) Max. sound pressure level Contact pressure dynamic circumaural, closed 45–15,000 Hz 300/150 Ω, mono > 25 – 40 dB 120 dB (± 5%) approx. 10 N 앚 50/35 Ω, mono electret mic capsule, noise-compensated, MKE 45-1 300–5,000 Hz – 120 dB 150 Ω 400 mV ± 3 dB at 114 dB (as per RTCA/DO 214) typ. 16 V DC (8 – 16 V DC, approx.
HMEC 305 앚HMEC 305-C 앚HMEC 322 앚HMDC 322 General data Connecting cable Weight without cable Power supply for NoiseGard™ Current consumption Fuse Connectors Controls Temperature range Operating time Battery pack 1.5 m, unilateral 앚 coiled cable, unilateral 370 g 12–35 V DC 27 mA (zero signal current), max. 80 mA 500 mA thermo fuse XLR-5 for headphones, 앚 XLR-5 for headphones 앚 U-174/U jack plug for headphones and microphone, microphone and 앚 and microphone.
Certificate of Conformity Sennheiser electronic GmbH & Co. KG declare that this device conforms to the applicable CE standards and regulations. For up-to-date information on Sennheiser products, you can also visit the Sennheiser Web site at “http://www.sennheiser.com”.
