Audio Precision AECM206 User manual
AECM206
headphone test fixture
User’s Guide and Specifications
November, 2017
model AECM206
Copyright © 2011–2017 Audio Precision, Inc.
All rights reserved.
Printed in the United States of America.
No part of this manual may be reproduced or transmitted
in any form or by any means, electronic or mechanical, in-
cluding photocopying, recording, or by any information
storage and retrieval system, without permission in writing
from the publisher.
Audio Precision, AP, and APx are trademarks of Audio
Precision, Inc. Windows™ is a trademark of Microsoft Cor-
poration. Dolby and the double-D symbol are trademarks
of Dolby Laboratories, Inc. DTS is a trademark of DTS, Inc.
pn 8211.0354 rev 000 XVII1114095536
Audio Precision
5750 SW Arctic Drive
Beaverton, Oregon 97005
503-627-0832
800-231-7350
ap.com
Documentation and Support
This booklet contains a user’s guide and full specifications for the Audio Precision
AECM206 Headphone Test Fixture. The AECM206 is an acoustic accessory that requires
ICP® powering for its internal microphones, and typically requires an audio analyzer such as
an Audio Precision APx5 Series for signal measurement and analysis.
ap.com
Visit the Audio Precision web site at ap.com for APx support information and APx
resources. You can also contact our Technical Support staff at techsupp[email protected], or by
telephoning 503-627-0832 ext. 4, or 800-231-7350 ext. 4 (toll free in the U.S.A.).
Serial Numbers
The internal microphones and preamplifiers are mated and calibrated as a pair, and must
be maintained as a pair for the TEDS calibration to remain valid. Record your serial numbers
here for reference.
AECM206 Headphone Test Fixture sn ______________________________
Left Ear Usage (blue cable marking)
AECM304 Occluded Ear Simulator sn ______________________________
(with embedded microphone)
426M15 preamplifier sn ______________________________
Right Ear Usage (red cable marking)
AECM304 Occluded Ear Simulator sn ______________________________
(with embedded microphone)
426M15 preamplifier sn ______________________________
AECM206 Headphone Test Fixture: Table of Contents i
Table of Contents
User Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
What’s in the box?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Inspection and preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Removal from packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pinnae part numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Orientation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Attaching the pinnae. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Connection to analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Powering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
TEDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Factory Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Local Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 1: Table of Contents
ii AECM206 Headphone Test Fixture: Table of Contents
Test Use Case. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Removing the alignment ring plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Removing the preamplifier/microphone system from the head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Removing the preamplifier/microphone system for shipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Separating the preamplifier from the microphone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Removing the head from the neck. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Reinstalling the preamplifier/microphone system and cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
AECM206 Headphone Test Fixture: User’s Guide 1
User’s Guide
Overview
The AECM206 is a well-isolated headphone test fixture that
supports standards-compliant headphone, earphone, earbud
and hearing protection (ear muff) testing.
Symmetrical, anatomical pinnae are provided in two hard-
nesses, accommodating circum-aural, supra-aural, intra-
concha, and insert earphone testing.
In the head of the fixture are two AECM304 ear simulators
(acoustic couplers with built-in measurement micro-
phones). Each AECM304 is fitted with an ear canal exten-
sion and connected to a 426M15 preamplifier and cable.
The fixture is stabilized and mounted on a steel base that
helps to isolate mechanical vibrations during testing.
The AECM206 complies with applicable portions of the
International Standards ISO 4869-3 and IEC 60318-4.
User’s Guide
2 AECM206 Headphone Test Fixture: User’s Guide
What’s in the box?
The AECM206 is delivered surrounded by protective contoured foam, shipped in either a cardboard carton or an optional hard
travel case. The fixture is fully assembled and ready for immediate use.
Figure 1. AECM206 as packaged for shipment
Cases for
AECM304
shipping
Cases for
426M15
shipping
Pinnae
Shore A-25
Pinnae
Shore OO-35
Fixture
lifting sling
Tools and
silicon
grease
Headphone
Test
Fixture
USB drive
documents
ADP105
adapter
for
CAL250
Space for
optional
CAL250
Coiled mic
cables
User’s Guide
AECM206 Headphone Test Fixture: User’s Guide 3
Inspection and preparation
Removal from the packaging
See Figure 1. The test fixture is protected for shipment by
contoured foam in a strong carton or hard travel case. The
fixture must be removed with care. For this purpose, a sling
is provided. Pull the sling upwards with one hand while eas-
ing the base of the test fixture out of the case with the other
hand.
Carefully remove the coiled audio cables from their cavity.
Be sure to carefully coil the cables, and to encircle the test
fixture with the sling when replacing it into the foam cutout.
To carry the AECM206, support both the neck and head
simultaneously.
Components
The headphone test fixture consists of a massive tubular
head, fitted on a neck, which is connected to a circular base.
The head encloses an internal cavity where the ear simula-
tor/preamplifier assemblies are mounted. The hat provides a
support for the headband provided with most headphones.
The AECM304 ear simulator is fitted with an internal mea-
surement microphone and is threaded for attachment to the
426M15 preamplifier. Each AECM304/426M15 assembly
is a mated pair, calibrated together. The components must
not be interchanged between assemblies.
At the acoustic end, each AECM304 is fitted with an ear
canal extension. The ear canal extensions project slightly
from the right and left side ends of the head. An alignment
ring plate is mounted on each end, to secure the pinnae and
aid in alignment when mounting headphones. See Figures 2
through 6.
Figure 2. Headphone Test Fixture key components
Face
Alignment
ring plate
Alignment
stud
Hat
Head
Neck
Neck cavity
(located in back)
Base
Collar
Preamplier
cables
User’s Guide
4 AECM206 Headphone Test Fixture: User’s Guide
Figure 3. AECM206-RING alignment ring plate and screws.
Two such rings are mounted on the AECM206.
Figure 4. ADP105 Adapter for CAL250.
Figure 5. 2.5 mm, 2 mm and 1.5 mm hex drivers; silicon
grease.
Figure 6. An AECM304, shown here fitted with an
ear canal extension to the left in the photograph, and mated
to an 426M15 preamplifier, shown to the right. Two such
assemblies are mounted within the AECM206 head.
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