BOSE A20 Aviation Headset Owner's Guide

A20™ AVIATION HEADSET

Owner’s Guide

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SAFETY INFORMATION

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EnglishTab 2 , 10

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. This equipment generates, uses,
and can radiate radio frequency energy and,
if not installed and used in accordance with
the instructions, may cause harmful
interference to radio communications.
However, there is no guarantee that
interference will not occur in a particular
installation. If this equipment does cause
harmful interference to radio or television
reception, which can be determined by
turning this equipment off and on, the user is
encouraged to try to correct the interference
by one or more of the following measures:

– Re-orient or relocate the receiving

antenna.

– Increase the separation between this

equipment and receiver.

– Connect this equipment into an outlet on

a circuit different from that to which the
receiver is connected.

– Consult Bose or an experienced radio/TV

technician for help.

Changes or modifications not expressly
approved by Bose Corporation could void
the user’s authority to operate this
equipment.

Operation is subject to the following two
conditions: (1) This device may not cause
harmful interference, and (2) this device
must accept any interference received,
including interference that may cause
undesired operation.

This device complies with FCC and Industry
Canada RF radiation exposure limits for
general population. It must not be collocated
or operating in conjunction with any other
antenna or transmitter.

Bose Corporation hereby declares
that this product is in compliance
with the essential requirements
and other relevant provisions of
Directive 1999/5/EC and other
applicable Directives. The
complete Declaration of
Conformity can be found at
www.Bose.com/compliance.

Operate this product within the temperature
range of 5°F to 131°F (-15°C to 55°C) only.

Important Safety Instructions

• Please read these instructions carefully
and completely before using the headset.

• Make these instructions easily accessible
to all users at all times. Always include
these instructions when passing the
headset on to third parties.

• During flight operations, do not use the
headset for telephone calls.

• It is the responsibility of each aircraft
operator or pilot in command to
determine that any and all portable
devices will be free of any interference
with the navigation or communication
system of the aircraft. In addition, it is
their responsibility to determine the
suitability of the performance of portable
devices in relation to the use of the

®

A20™ Aviation Headset.

Bose

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

• Never repair or attempt to repair a
defective headset yourself. Contact

®

Technical Support. Refer to

Bose
“Contact information” on page 37.

• Do not immerse the headphones in water
or any other liquid. See “Cleaning the
headset” on page 23 for cleaning
instructions.

• Warning:
Choking hazard.
Keep the
batteries away
from children.

• Danger of explosion if batteries are
incorrectly replaced. Replace only with
AA alkaline batteries. Batteries may
cause a fire or chemical burn if
mishandled. Do not recharge,
disassemble, heat, or incinerate.
Dispose of used batteries properly.

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Tab 6, 14

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CONTENTS

ADVISORIES 1

Operational advisory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Hearing safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Volume control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Recognizing aircraft sounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Using audio sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Headset earcup requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Earcup inner screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

INTRODUCTION 4

What’s included . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

What’s in the carton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Control module variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Power and cable variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

PREPARING THE HEADSET FOR USE 8

The microphone assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Attaching the microphone assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

The battery compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Opening the battery compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

The operation switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Inserting and replacing the batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Connecting the headset to the aircraft . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Using the 6-pin plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Using the dual general aviation plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Using other plug types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

USING THE HEADSET 13

Wearing and adjusting the headset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Conditions related to fit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Microphone placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Clothing clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Using the control module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Power button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Volume control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Power indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Auxiliary (AUX) audio input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Audio priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Using the headset with a Bluetooth

Pairing the headset with your phone . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Bluetooth

®

volume control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Making and answering calls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

®

technology-enabled phone . . . . . . . 19

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CONTENTS

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EnglishTab 2 , 10

HEADSET CARE AND MAINTENANCE 23

Instructions for continued airworthiness . . . . . . . . . . . . . . . . . . . . . . . . . 23

Cleaning the headset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

General cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Headset earcup openings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Microphone windscreen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Earcup inner screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Headband cushion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Replacing parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Microphone windscreen replacement . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Ear cushion replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Battery replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Headband cushion replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Microphone assembly or access cover replacement . . . . . . . . . . . . . . 26

TROUBLESHOOTING 27

In case of difficulty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

INSTALLATION 31

Mounting the aircraft panel connector . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Details on making the connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

TECHNICAL INFORMATION 34

SERVICE AND WARRANTY INFORMATION 36

Locating the headset serial number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Warranty period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Limited warranty service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

To return your headset to Bose for repair . . . . . . . . . . . . . . . . . . . . . . . 36

Contact information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Ordering parts and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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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.

Note: The headset includes redundant circuitry to reduce the effects of such failures
and to allow for continued use of the headset in the passive noise reducing mode.

In passive noise reducing mode, the volume controls on the control module will
automatically be set to maximum volume. If additional volume control is
needed, you can use the intercom or radio volume control.

Acoustic Noise Cancelling mode is active when the headset control module is
powered on (power indicator is lit). The headset is in the passive mode when
the power is off (power indicator is not lit). See “Control module variations” on
page 6.

If your headset is aircraft powered, connect the headset to the aircraft power
sources only as described in “Connecting the headset to the aircraft” on
page 11. The headset will not operate properly if used with any battery source
other than the Bose A20 Aviation Headset control module.

1

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EnglishTab 2 , 10

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

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.

As pilot in command, you must be sure you can understand critical
communications even with Acoustic Noise Cancelling
case, you may need to turn up the aircraft communications system volume.

Avoid setting the volume controls at levels high enough to impair your hearing
during extended periods of headset use.

Recognizing aircraft sounds

With the headset’s active and passive noise reduction, typical aircraft sounds
(such as engines, propellers, warning alarms, and other sound sources) may
not sound familiar. We strongly advise you to make sure you can hear and
recognize these sounds when using the Bose
operating any aircraft.

mode turned off.

mode turned off. In this

®

A20™ Aviation Headset while

Using audio sources

When listening to in-flight entertainment, or a portable audio source through a
Bose A20 Aviation Headset, be sure to limit the volume to safe levels that do
not interfere with your ability to hear informational sounds and warning alarms,
such as stall warnings or gear up, while piloting.

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Tri Po rt
opening

Microphone
opening

Earcup
inner screen

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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.

Earcup inner screen

The protective inner screen is critical to the headset’s ability to reduce noise.

Do not attempt to remove, replace, or repair this screen. If screen replacement
seems necessary, contact Bose

®

Technical Support. See “Contact information”

on page 37.

If the screen gets wet or any foreign objects become lodged on or adjacent to
it, follow the instructions in “Headset Care and Maintenance” on page 23.

Storage

Store the headset in a ventilated area away from direct sunlight. Remove the
batteries before storing the headset for extended periods.

3

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EnglishTab 2 , 10

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
technology.

®

wireless

What’s included

Each Bose A20 Aviation Headset is supplied with a control module, cable, and
carrying case. The type of control module and end-plug configuration depends
on the options you chose for your headset.

There are two options for the control module:

• Control module with Bluetooth wireless technology

• Conventional control module

There are several end-plug configurations for the headset. Your headset falls
into one of two general categories:

• Dual-powered: Aircraft powered with battery

• Battery-only powered

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Headphones

Carrying case

2 AA Alkaline

3.5 mm adapter cable

Headset assembly: Accessories:

Inline clothing clip

Inline clothing clip

Control module
See “Control module

variations” on page 6
for options.

Cable connector (varies)

batteries

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What’s in the carton

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INTRODUCTION

Note: Cable connector types will vary based on model of headset. See “Power
and cable variations” on page 7.

5

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Bluetooth

Bluetooth

Bluetooth control module Conventional control module

Left/Right volume controls*

Power button

Power indicator

indicator

Bluetooth

Bluetooth

function button

Volume Up button

Volume Down button

*Control the intercom volume

Multifunction
switch:

Top

Intercom
prioritized

Middle

Intercom
mixed

Bottom

Intercom
only

Audio Priority
switch:

Top

Intercom
prioritized

Middle

Intercom
mixed

Bottom

Intercom
only

Auxiliary (AUX)
audio input

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EnglishTab 2 , 10

INTRODUCTION

Control module variations

If you opted for Bluetooth® wireless technology, you received the control
module featuring Bluetooth technology. If not, you received the conventional
control module.

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Tab 6, 14

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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.

7

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Access
cover

Connector
pins

Microphone assembly

Connector pins

L for left

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EnglishTab 2 , 10

PREPARING THE HEADSET FOR USE

The microphone assembly

Your headset may be shipped with the microphone assembly (boom microphone
and cable) attached to the left earcup. If your headset is shipped with the
microphone assembly packed separately, you can attach it to either earcup.

Attaching the microphone assembly

Choose the earcup (L or R) to receive the microphone assembly. Also, make
sure that the earcup connector pins are clean and free of debris.

1. Use a Phillips screwdriver to loosen the two screws on the access cover
near the bottom of the earcup where you want to attach the
microphone assembly.

2. Remove the access cover to reveal the connector pins on the earcup.

3. Carefully line up the microphone assembly to the small connector socket

on the earcup.

4. Slide the connector into the socket until it reaches the stop.

CAUTION: Do not force the connector into the socket, or earcup damage may
occur.

5. Tighten the screws to secure the assembly.

6. Attach the access cover to the earcup that does not have the microphone

assembly attached. Insert the screws, then align and tighten them.

Note: The headset will not work without the access cover installed.

CAUTION: Be sure to try the headset and fully test its operation before flight.

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Operation switches

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PREPARING THE HEADSET FOR USE

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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.

Opening the battery compartment

You must open the battery compartment to access the operation switches.
Press down firmly on the battery compartment cover finger indent and slide the
cover down. The cover is tethered to the module. Do not attempt to detach it.

Note: The battery compartment cover is designed to remain securely closed. You
may need to use additional force when pressing down and releasing cover.

The operation switches

The operation switches control the Auto Off function and whether you hear
audio in one or both ears.

To change the operation switches

1. Open the battery compartment.

2. If batteries are installed, remove them.

In the battery compartment, you can observe and change the switch positions.

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EnglishTab 2 , 10

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 possible positions, default setting, and purpose for
each switch.

Switch Options Purpose

1. Auto Off
function

2. Mono/Stereo
selection

ON, OFF

Default: ON

Mono, Stereo

Default: MONO

Set at the factory to enable the Auto Off function. The
headset will turn off after 3 to 9 minutes of inactivity.
To disable Auto Off, set the switch to OFF. With the
switch in OFF position, the Acoustic Noise
Cancelling
and hold the power button for at least one second.

Set at the factory for mono audio systems (to
provide audio in both ears). Set it to stereo (ST) if
your aircraft has a stereo intercom.

®

system will not turn off until you press

Auto Off functionality

The Auto Off feature detects when the headset is not in use and shuts it off after
several minutes to preserve battery power. The exact time it takes to shut off
varies and can range between 3 to 9 minutes after you stop using the headset.

When the headset is running on battery power only and is not plugged in to an
intercom, it will shut off even when there is an auxiliary input present.

If you are on a phone call and unplugged from an intercom, the headset will
allow you to complete your call, then it will turn off approximately three seconds
after the call is terminated.

Note: To use the headset when unplugged from the intercom to listen to auxiliary
input audio or as a Bluetooth

®

wireless technology-enabled headset to make or receive

calls, we recommend you disable the Auto Off feature for uninterrupted functionality.

Inserting and replacing the batteries

CAUTION: If the batteries do not fit correctly, do not force them in. Forcing an
improper connection will cause permanent damage to the control module.

To insert or replace the batteries

1. Turn off headset power.

2. Press down firmly on the battery compartment cover and slide the cover to

release. The battery door is tethered. Do not detach the door from the
control module.

3. Insert the two supplied alkaline AA batteries into the control module,
observing proper polarity.

4. Replace the battery compartment cover.

Note: Rechargeable batteries will alter the accuracy of the battery power indicator.

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