GRAS 48LX-4 User manual
LI0272 – 2 November 2020
Instruction Manual
GRAS 48LX-4 and 48LX-8 UTP Line Arrays
Mounting and In-Situ Verication
Instruction Manual
Revision History
Revision Date Description
1 2 November 2020 First edition
Copyright Notice
© 2020 GRAS Sound & Vibration
http://www.grasacoustics.com
Any technical documentation that is made available by GRAS is the copyrighted work of GRAS
and is owned by GRAS.
The content in this document is subject to change without notice. GRAS Sound & Vibration is not
liable or responsible for any errors or inaccuracies that may appear in this document.
Trademarks
Any product names mentioned in this document may be trademarks or registered trademarks of
their respective companies and are hereby acknowledged.
Do not touch the diaphragm
Instruction Manual
Contents
Introduction ......................................................................................................................4
Mounting............................................................................................................................4
Mounting on Curved Surfaces ...........................................................................................................5
Verication ........................................................................................................................6
............................................................................................................6
The Adapter.............................................................................................................................................6
Procedure................................................................................................................................................ 7
Ordering Information ......................................................................................................8
...................................................................................................................................8
Mounting Accessories ..........................................................................................................................8
Warranty, Service and Repair.........................................................................................8
Warranty, Service and Repairs............................................................................................................8
Instruction Manual
Introduction
Ease of use when preparing for measurements is important. The UTP line arrays are easy to handle
it easy to verify the integrity of the measurements setup after mounting/prior to measurements.
Mounting
The 48LX-4 and 48LX-8 line arrays consist of four and eight UTP microphones mounted on
sides and ends for mounting with masking tape as shown below.
When reinstalling the line arrays, the original geometry is automatically retained.
A
A
29.0
2.5
1.0
7.5 °
1.0
6.5°
41.0
27.0
Cable cover
Mounting tape
The GRAS DB0507 Mounting Tape for 48LX Series Line-Arrays is recommended. It is a
moisture. For indoor use only.
Fig. 1. Line array mounting with masking tape.
Important. Having mounted the strip with tape, you probably will want to also secure the cable to
the structure. When doing this, ensure that you do not accidentally pull the cable away from the
strip. There is a built-in strain relief under the cable cover but it is still necessary to be careful to
protect the cable assembly from strain as all parts are very small.
Cleaning after Removal
Residues from the tape can be removed by gently rubbing with a cleaning tissue (part of the
delivery) or a soft cloth moist with pure alcohol.
Instruction Manual
Mounting on Curved Surfaces
As shown below, the radius of the bend must not be less than 500 mm. Mounting on a smaller
For the 48LX-4 this corresponds to an arch with a height of 16.8 mm, and for the 48LX-8 it cor-
responds to an arch with a height of 52 mm.
16.8 mm
R 500.0 mm
R 500.0 mm
52.0 mm
Fig. 2. Showing how much 48LX-4 And 48LX-8 can be bent.
Maximum curvature
Radius Arch height
48LX-4 500 mm 16.8 mm
48LX-8 500 mm 52 mm
Instruction Manual
Verication
In-Situ Sensitivity Verication
dismounting.
Proper laboratory calibration of sensitivity and frequency is covered by a separate manual.
The Adapter
The adapter has three main features.
•
adapter.
• It has a soft cushion similar to those found on circumaural headphones. It creates a closed
• It has four distance spacers that ensure – when the cushion is depressed – that the cavity is
Top view Side view
1” collar
Soft cushionSpacers
Fig. 3. The RA4800 adapter/eld verication set for level calibration.
Instruction Manual
Procedure
Important.
sensitivity.
G.R.A.S. 42AG
dB Hz Met
dB Hz Met
G.R.A.S. 42AG
dB Hz Met
dB Hz Met
Fig. 4. In-situ verication using 42AG and RA4800.
Place the calibrator over the microphone and press it down until stopped by the four distance
spacers. You must keep it still in this position during the calibration.
When you have turned on the calibrator and pressed it down over the microphone, you must keep
-
cation can be done quite quickly.
Refer to the manual for 42AG for further information about how to operate the calibrator.
Correction Factors
Frequency Correction Factor Accuracy
± 0.2 dB
± 0.2 dB
Instruction Manual
Ordering Information
Verication Items
42AG Multifunction Sound Calibrator
RA4800
Mounting Accessories
Mounting Tape
Cleaning Tissue
Warranty, Service and Repair
Warranty, Service and Repairs
GRAS products are made of components from our proven standard portfolio and are all manu-
factured of high-quality material and branded parts that were chosen and processed to ensure
life-long stability and robustness.
The warranty does not cover products that are damaged due to negligent use, an incorrect power
supply, or an incorrect connection to the equipment.
Further information about warranty and our repair service can be found at
grasacoustics.com/repair-center
WEEE directive:
2002/96/EC
CE marking directive:
93/68/EEC
Manufactured to conform with:
RoHS directive:
2002/95/EC
GRAS Sound & Vibration continually strives to improve the quality of our products for our
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