©2010 Bose Corporation, The Mountain, Framingham, MA 01701-9168 USA AM325664 Rev.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English SAFETY INFORMATION NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 Contents ADVISORIES Operational advisory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hearing safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Volume control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recognizing aircraft sounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English HEADSET CARE AND MAINTENANCE Instructions for continued airworthiness . . . . . . . . . . . . . . . . . . . . . . . . . Cleaning the headset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Headset earcup openings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 ADVISORIES Operational advisory The Bose® A20™ Aviation Headset incorporates Acoustic Noise Cancelling® technology. As with any complex electronic device, it is possible for this headset to fail during operation. Symptoms of failure may include loud tones, distortion, and loss of communications signal in the headset when used in the Acoustic Noise Cancelling® mode.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English ADVISORIES Hearing safety The headset is intended for use with the Acoustic Noise Cancelling® mode turned on. Noise reduction and communications performance are reduced with Acoustic Noise Cancelling® mode turned off. Volume control Make sure your aircraft communications system volume control is easily accessible. This control affects the strength of the communications signal coming into the headset.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 ADVISORIES Headset earcup requirements Proper headset operation requires that the headset TriPort® openings on the earcup are kept free of debris. The headset TriPort® openings are located on the outside of each earcup and include two holes and a screen. TriPort® opening Microphone opening Earcup inner screen The protective inner screen is critical to the headset’s ability to reduce noise.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English INTRODUCTION Congratulations on your purchase of a Bose® A20™ Aviation Headset. The Bose® A20™ Aviation Headset is our most advanced aviation headset yet. It delivers significantly increased noise reduction and provides a more comfortable fit, without compromising the clear audio you expect from Bose. Plus, it offers auxiliary audio input and is available with Bluetooth® mobile phone connectivity.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 INTRODUCTION What’s in the carton Headset assembly: Accessories: Headphones Carrying case In-line clothing clip Control module See “Control module variations” on page 6 for options. In-line clothing clip Batteries 3.5 mm adapter cable Cable connector (varies) Note: Cable connector types will vary based on model of headset. See “Power and cable variations” on page 7.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English INTRODUCTION Control module variations If you opted for Bluetooth® capability, you received the Bluetooth® control module. If not, you received the conventional control module.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 INTRODUCTION Power and cable variations The Bose® A20™ Aviation Headset is available for purchase in different standard aircraft connector options to suit pilot needs including: • • • • Dual G/A 6-pin install* 5-pin XLR U174 * An adapter is available from Bose to convert a 6-pin connector to a dual G/A plug for additional connection flexibility. Other configurations require the purchase of a cable assembly.
Tab 8, 16 Tab 7, 15 PREPARING Tab 6, 14 THE Tab 5, 13 HEADSET Tab 4, 12 FOR Tab 3, 11 Tab2, 10 English USE The microphone assembly Your headset is shipped with the microphone assembly (boom microphone and cable) attached to the left earcup. If the microphone assembly is packed separately, you can attach it to either earcup. Attaching the microphone assembly Choose the earcup (L or R) to receive the microphone assembly.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 PREPARING THE HEADSET FOR USE The battery compartment The Bose® A20™ Aviation Headset is shipped with factory-set operation defaults. If you want to alter these defaults, you can change the operation switches located inside the control module battery compartment. If you do not want to change any of the operation switches, skip ahead to “Inserting and replacing the batteries” on page 10.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English PREPARING THE HEADSET FOR USE 3. To change a switch position, use a pen or a small, flat-tipped screwdriver to gently move the switch. The following table shows, for each switch, its possible positions, default setting, and purpose. Switch Options Purpose 1 ON, OFF Set at the factory to enable the Auto off function. The headset will turn off after 3 to 9 minutes of inactivity.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 PREPARING THE HEADSET FOR USE Connecting the headset to the aircraft The Bose® A20™ Aviation Headset can be configured to either plug into aircraft power or rely entirely on battery power. Using the 6-pin plug A single 6-pin plug inserted into the 6-pin connector provides the headset with aircraft power and intercom audio.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English PREPARING THE HEADSET FOR USE Using the dual general aviation plugs The most common battery powered (only) version of the headset has two general aviation (GA) plugs that connect to the aircraft audio. Although the plugs look similar, the microphone plug is shorter, thinner and has a slightly different shape than the intercom plug. Insert the thicker intercom plug in first. It will only fit into one of the jacks.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 USING THE HEADSET Wearing and adjusting the headset Proper fit on your head is important both for comfort and optimal noise reduction performance. Here are a few guidelines: • Use the left (L) and right (R) markings above the earcups to orient the headset properly. R L • As you put the headset on, lightly grasp each earcup and adjust it so its cushion is completely over your ear.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English USING THE HEADSET 1. Grasp the boom with your fingers and move the microphone up or down so it is level with your mouth. 2. Pull the microphone in toward your lips. Position the microphone with its talk side facing in. Though it will be slightly off center, the microphone should be 1/ inch from the opening of your lips. 2 Mic label Mic is 1/2 inch from mouth Mic is too far away Mic label is not facing mouth 3.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 USING THE HEADSET Using the control module Use the control module to control the headset functions. There are two variations of the module; one that works with Bluetooth® and one that has basic functions only.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English USING THE HEADSET Power button Use the power button to turn Acoustic Noise Cancelling® on or off, and control indicator brightness. • Press the power button once to turn on Acoustic Noise Cancelling® noise reduction. • Press and hold the power button to turn off Acoustic Noise Cancelling® noise reduction. • Double click the power button to dim the power and Bluetooth® indicators.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 USING THE HEADSET Auxilliary (AUX) audio input The Bose® A20™ Aviation Headset provides a 1/8 inch (3.5 mm) AUX audio input that allows you to use your headset with an external audio source such as a portable GPS or a portable audio device. The connector is located at the bottom end of the control module as shown. AUX audio input Your headset includes a 1/8 inch (3.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English USING THE HEADSET Multifunction/Audio priority switch The multifunction/audio priority switch has three positions: Position Function Operation Top Intercom prioritized over AUX When the switch is in the top position and an intercom signal is detected, AUX audio is muted.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 USING THE HEADSET Using the headset with a Bluetooth® enabled phone Pairing the Headset with your phone Before you use your Bose® A20™ Aviation Headset with your mobile phone, you must pair the two devices. This entails putting the Bose® A20™ Aviation Headset in pairing mode, setting your Bluetooth® phone to “discover” the headset, then confirming the connection on the phone. 1.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English USING THE HEADSET Note: The Bose® A20™ Aviation Headset will automatically exit pairing mode after five minutes of inactivity.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 USING THE HEADSET Bluetooth® volume control The Bluetooth® volume control increases or decreases the volume of the mobile phone that is paired to the Bose® A20™ Aviation Headset. The Bluetooth® volume control is located on the right side of the control module. You can only adjust Bluetooth® volume during an active phone call. To change the volume, press the volume up or volume down button.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English USING THE HEADSET Making and answering calls To make a call Dial from your mobile phone, and the call will automatically transfer to the headset. If your phone has voice activated dialing, press the Bluetooth® function button and wait for the phone voice prompts. To activate voice dialing When there are no active or incoming calls, briefly press the Bluetooth® function button.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 HEADSET CARE AND Tab 7, 15 Tab 8, 16 MAINTENANCE Instructions for continued airworthiness Bose® recommends following the general care and maintenance instructions in this guide. With normal use, items such as windscreens and ear cushions may require periodic replacement. If cleaning or replacement of these items is needed, follow the recommendations on the following pages.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English HEADSET CARE AND MAINTENANCE Microphone windscreen Remove the windscreen from the microphone as described in “Microphone windscreen replacement” on page 24. Rinse and air-dry the windscreen. Make sure the windscreen is completely dry, then reattach. Earcup inner screen Do not attempt to remove, replace, repair, or clean this component. Located inside the earcup, the inner screen is critical to proper headset operation.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 HEADSET CARE AND MAINTENANCE Ear cushion replacement As a general rule, ear cushions should be replaced every six months or every 350 hours of use, depending on how often you fly.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English HEADSET CARE AND MAINTENANCE Headband cushion replacement The headband cushion is designed to give the maximum level of comfort to your headset. Bose recommends that you replace the cushion after regular care and maintenance fails to restore the wool pile to its original size and shape. To replace the cushion: 1. On a protected surface, turn the headset upside down. Remove the old cushion from the headband. 2.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 TROUBLESHOOTING In case of difficulty Look for the problem in the left column of the table, then follow the “What to do” instructions in the right column. If the problem persists, contact Bose, using the contact information on page 37 of this guide for assistance. CAUTION: Do not attempt to disassemble or service the inside of the earcups or other parts of the headset.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English TROUBLESHOOTING Problem What to do Low volume of incoming communications • Check to see if the volume controls are set too low. See “Volume control” on page 16 for instructions on volume adjustment. • Ensure that the stereo/mono switch is correctly set for your intercom system. • Check that all headsets sharing the intercom have the stereo/mono switch in the correct position.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 TROUBLESHOOTING Problem What to do Low rumbling sound with the headset turned on in a quiet environment • Adjust the earcup fit to create a better seal on your head. The low-force design of the headset makes it sensitive to items that interfere with the seal around your ear. Make sure that your ears are completely inside the ear cushions, and that a hat or eyeglasses with thick temples do not interfere with the seal.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English TROUBLESHOOTING Problem What to do Cannot hear communications while listening to audio from aux input or aux input does not mute with incoming communications • Check headset prioritization settings. See “Multifunction/Audio priority switch” on page 18. • Make sure all connections are secure (headset to intercom, aux input to headset).
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 INSTALLATION Mounting the aircraft panel connector The aircraft panel connector is part of the optional 6-pin wiring harness assembly. Contact Bose® Technical Support, using the contact information on page 37 of this guide, for purchase information. CAUTION: The aircraft panel connector must be mounted by a technician who is qualified to perform this type of avionics installation for the aircraft you are using.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English INSTALLATION CAUTION: Do not use excessive force or bend the installed connector. This may damage or break internal solder joints. Note: The aircraft panel connector cannot be installed to an audio system using transformer-coupled audio outputs. Contact the Bose® Technical Support, using the contact information on page 37 of this guide, for details.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 INSTALLATION Helicopter connection diagram WHT/BLU 6 MIC LO WHT 5 MIC HI BLU 4 COMM R WHT 3 COMM L BLK 2 GND 10-32 RED 1 V+IN V DC 1/2A Existing single 4prong jack Existing wiring to helicopter intercom/ audio panel Barrel (audio gnd) Note: Barrel ground (gnd) refers to aircraft grounds.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English TECHNICAL INFORMATION Headphone Damage could occur to avionics equipment that is intended for use only with 600-ohm headsets. If in doubt, consult the avionics equipment manufacturer. Impedance Monaural mode: 160 Ohms ON and OFF Stereo mode: 320 Ohms ON and OFF Frequency response 15 Hz to 15 kHz Sensitivity: 92 dB SPL typical, measured at 1 mw, 1 kHz, full volume on a KEMAR ear simulator.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 TECHNICAL INFORMATION FAA Technical Standards Order The Bose® A20™ Aviation Headset, its interface, cables, and electret microphone, are FAA approved to TSO C139.
Tab 8, 16 Tab 7, 15 Tab 6, 14 Tab 5, 13 Tab 4, 12 Tab 3, 11 Tab2, 10 English SERVICE & WARRANTY INFORMATION Locating the headset serial number Your Bose® A20™ Aviation Headset is identified by a unique headset serial number located on the underside of the headband and underneath the headband cushion. Reference this serial number when you register your product or contact Bose for technical support.
English Tab 2, 10 Tab 3, 11 Tab 4, 12 Tab 5, 13 Tab 6, 14 Tab 7, 15 Tab 8, 16 SERVICE & WARRANTY INFORMATION Contact information Contact Bose for: • • • • Spare parts and accessories Technical advice Installation information Warranty and repair information. In North America: Bose® Technical Support 145 Pennsylvania Avenue Framingham, MA 01701-9168 USA TEL: 1-800-233-4416 (US); 508-879-7330, ext. 62006 (outside US) FAX: 1-508-766-5997 E-MAIL: aviationheadsetsupport@Bose.
©2010 Bose Corporation, The Mountain, Framingham, MA 01701-9168 USA AM325664 Rev.
