Nti AL1 User Manual

ACOUSTILYZER

AL1

User Manual

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Contact details:

Headquarter [phone] [e-mail]
Americas [phone] [e-mail]
China [phone] [e-mail]
Czech [phone] [e-mail]
Germany [phone] [e-mail]
Japan [phone] [e-mail]
South Korea [phone] [e-mail]
UK [phone] [e-mail]

www.nti-audio.com

NTi Audio AG
Im alten Riet 102, 9494 Schaan
Liechtenstein, Europe

is an ISO 9001:2008 certied company.

© NTi Audio AG
All rights reserved.
Subject to change without notice.
Release Oct 2017 / Firmware A1.32 or higher

MiniLINK, Minilyzer, Digilyzer, Acoustilyzer, Minirator,
MiniSPL and Minstruments are trademarks of NTi Audio.

Made in

Switzerland

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Contents

1. Introduction 4

Registration 5
CE Declaration of Conformity 6
International Warranty and Repair 7
Warnings 8
Test & Calibration Certicate 8

2. Overview 9

Acoustilyzer Functions 10
Easy Operation 10
Connectors 11

3. Basic Operation 13

Start-up Screen 14
Menu Bar 14

4. Measurement Functions 23

SPL/RTA - Sound Level Meter 24
SPL/RTA - Real Time Analyzer RTA 28
Reverberation Time RT60 37
FFT Analysis 43
Polarity Test 47
Delay Time 49
Electrical Measurements - RMS/THD 52
Speech Intelligibility STI-PA (optional) 54
Calibration 62

5. MiniLINK PC Software 65

Installation 65
Start the MiniLINK PC Software 66
Free Registration of your Test Instrument 67
Readout of Stored Test Results 68
Visualizing the Test Results 69
Test Result Logging at the PC 73
Remote Test Instrument Control with the PC 75
MiniLINK Tools 76
Activate Options 82

6. Troubleshooting 83

7. Accessories 84

8. TechnicalSpecication 86

9. Appendix: Introduction to STI-PA 89

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1. Introduction

Congratulations and thank you for buying NTi Audio’s Acoustilyzer AL1,
a product specially suited for professional acoustical test applications.
The Acoustilyzer offers advanced acoustic functions including an optional
speech intelligibility STI-PA measurement module and further basic electrical
features. We are convinced you will enjoy using it!

This manual describes the Acoustilyzer AL1 functions and measurements
in detail. Further application information about the acoustical and electrical
measurements can be found on the web site www.nti-audio.com.

The Acoustilyzer AL1 is available as a stand-alone test instrument or as a
crossgrade package for existing Minilyzer ML1 users. The same crossgrade
option can be used to install the Minilyzer functionalities on the AL1. The
STI-PA measurement feature is optional.

The product packages include the following items:

Acoustilyzer AL1 1x Acoustilyzer AL1

1x MiniLINK CD (PC software)
1x MiniLINK USB Cable
1x Acoustilyzer Test CD
1x Acoustilyzer User Manual

ML1-AL1 Crossgrade 1x MiniLINK CD (PC software)

1x Acoustilyzer Test CD (audio samples)
1x License Number Crossgrade
1x Acoustilyzer User Manual
1x Minilyzer User Manual

STI-PA Measurement
Option

1x STI-PA Test CD (STI-PA test signal)
1x License Number STI-PA
1x Acoustilyzer User Manual

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Registration

Register as a customer with NTi Audio and benet from the following

possibilities:

• Keep your products up-to-date

Access free rmware and software updates.

• Activate options

Enable additional functions for your products.

• Access premium content

Access downloads, information and specic support for your products.

• Receive application and product news

Sign in for the NTi Audio Newsletter.

• Get fast worldwide support

Register your products for fast support.

• Conrm your ownership

Allows us to contact you with important product notications and

provides a product record in case of loss or theft.

How to Register

• Open the web page http://my.nti-audio.com.

• You are prompted to login or create the My NTi Audio Account.

• The web page “My NTi Audio Products” opens.

• Select the product type and enter the serial number.

• Conrm with “Register”.

• Now your product is listed in the table “My NTi Audio Products“.

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Declaration of Conformity

We, the manufacturer NTi Audio AG, Im alten Riet 102, 9494 Schaan,
Liechtenstein, hereby declare that the product Acoustilyzer AL1 conforms
to the following standards or other normative documents.

• EMC: 2004/108/EG

• Harmonized standards: EN 61326-1

• Explosive atmospheres (ATEX): 94/9/EG

• Directive 2011/65/EC on the restriction of the use of certain hazardous

substances in electrical and electronic equipment (RoHS).

• Directive 2002/96/EC on waste electrical and electronic equipment

(WEEE).

This declaration becomes void in case of any changes on the product
without written authorization by NTi Audio.

Date: 1. September 2013
Signature:

Position of signatory: Technical Director

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International Warranty and Repair

International Warranty

NTi Audio guarantees the functionality of Acoustilyzer AL1 against defects
in material or workmanship for a period of one year from the date of original
purchase, and agrees to repair or to replace at its discretion any defective
unit at no cost for either parts or labor during this period.

Restrictions

This warranty does not cover damages caused through accidents, misuse,
lack of care, the attachment or installation of any components that were
not provided with the product, loss of parts, connecting the instrument to

a power supply, input signal voltage or connector type other than specied

or wrongly polarized batteries. In particular, no responsibility is granted for
special, incidental or consequential damages.
This warranty becomes void if servicing or repairs of the product are
performed by any party other than an authorized NTi Audio service center

or if the instrument has been opened in a manner other than specied in

this manual.
No other warranty, written or verbal, is authorized by NTi Audio. Except
as otherwise stated in this warranty, NTi Audio makes no representation
or warranty of any kind, expressed or implied in law or in fact, including,

without limitation, merchandising or tting for any particular purpose and

assumes no liability, either in tort, strict liability, contract or warranty for
products.

Repair

In case of malfunction, take - or ship prepaid - your NTi Audio Acoustilyzer
AL1 packed in the original box, to the authorized NTi Audio representative
in your country. For contact details see the NTi Audio web page
www.nti-audio.com.

Make sure to include a copy of your sales invoice as proof of purchase
date. Transit damages are not covered by this warranty.

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Warnings

In order to avoid any problems during the operation of the instrument, follow
the guidelines listed below:

• Usetheinstrumentfortheintendedpurposeonly.

• Neverconnecttheinstrumenttoahighvoltageoutputsuchas
apoweramplier,mainspowerplug,etc.

• Donotdisassembletheinstrument.

• Neverusetheinstrumentinadampenvironment.

• Remove the batteries as soon as they are at or if it is not

intended to use the instrument for an extended period of time.

Test&CalibrationCerticate

This is to certify the Acoustilyzer AL1 is fully tested to the manufacturer’s
specications. NTi Audio recommends calibration of this test instrument
one (1) year after purchase, and every subsequent one (1) year thereafter.

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2. Overview

The Acoustilyzer AL1 is a sophisticated
tool used to analyze acoustic signals. It
is designed for easy and quick detailed
analysis of the acoustic environment

and to carry out signicant electrical

measurements. An accurate overview
of the actual acoustic signal is displayed
on a large LCD.

The AL1 is a class 1 accuracy instrument
and available with the measurement
microphones MiniSPL (class 2) or
M2010 (class 1 frequency response).
Alternatively, other measurement
microphones can be used.

Class 1 acoustical analyzer

NTi Audio offers the class 1 frequency
response microphone M2010 (an external
phantom power supply is required). The
Acoustilyzer in combination with the
M2010 measurement microphone forms
a highly accurate class 1 acoustical
analyzer.

Class 2 acoustical analyzer

The Acoustilyzer in combination with
the MiniSPL forms a comprehensive
class 2 acoustical analyzer. MiniSPL
is a battery-powered measurement
microphone. It is the ideal accessory for
the Acoustilyzer.

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Acoustilyzer Functions

The Acoustilyzer AL1 features many
measurement functions, which are
accessible through a drop down menu bar.

The base element is the cursor (inverted
area), which may be navigated through the
various functions by using the cursor keys.

• SPL/RTA: Sound Pressure Level (SPL) & time-averaged sound

pressure level (Leq) measurements of wideband values.

Real Time Analysis (RTA) of octave or ⅓ octave values

• RT60: Reverberation time with 1/1 octave band resolution

• FFT: Real-time zoom Fast Fourier Transform (FFT)

• POLARITY: Polarity measurement of speakers and line signals

• DELAY: Delay time measurements between speakers

• RMS/THD: Root Mean Square (RMS) level and Total Harmonic

Distortion (THD) measurements

• STI-PA: Speech intelligibility measurement is visible after

Speech Transmission Index for Public Address systems
(STI-PA) license key has been activated

• CALIBRTE: Calibration of connected measurement microphone

Easy Operation

All selectable settings may be adjusted
simply by

• Pressing the enter key to select the

required value.

• Alternatively, for longer selection lists,

Unit selected with cursor to
change setting

the chosen eld ashes. Now select

the required value with the cursor keys.

Conrm the setting by pressing the enter

key again.

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Connectors

On top of the AL1, three connectors as well as the internal microphone are
located:

• The XLR and RCA inputs allow a signal to be fed into the AL1.
We recommend using the XLR input for best performance (minimum

noise oor and best dynamic range). In case a measurement

microphone with unbalanced output is used, connect to the XLR­input between pin 2 and 3.

• A 3.5 mm (1/8“) jack headphone monitor output is used to monitor
the electrical input signal.

• The internal microphone is used to test the polarity of loudspeakers

and for delay time measurements. SPL measurements are not
supported with this internal microphone.

XLR & RCA
Inputs

Monitor
Output

Internal
Microphone

Note: Never connect the XLR- and the RCA input at the same time!

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Battery Replacement

After unpacking, insert three (3) 1.5 V alkaline batteries, type AA, LR6, AM3
into the AL1 battery compartment as shown below. The typical life-time for
a set of alkaline batteries is 16 hours.

Notes:

• WedonotrecommendtheuseofrechargeableNiCd-orNiMH-

batteries.

• Donotinsertbatteriesofdifferenttypes.

• Replace all batteries at the same time - never mix old and new

batteries.

• Ensurethecorrectpolaritiesoftheinsertedbatteries.

• Removethebatteriesassoonastheyareator if it is not intended

to use the instrument for an extended period of time.

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3. Basic Operation

Despite the wide range of availability of measurement functions and optional
setups, the operation of the Acoustilyzer is almost self-explanatory.

Menu Bar

Test Result

Escape
button

Power On/Off­Backlight

Enter / Cursor
Keys

The LCD is divided into the menu bar on top and the measurement results
displayed below.

The cursor keys and the escape button allow straightforward navigation
through the available features

• Actual settings (measurement function, lters)

• Measurement results (numeric or graphic display)

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Start-up Screen

The start-up screen remains displayed by
pressing and holding any button during the
start-up of the unit. This allows you, for ex­ample, to read the instrument serial num­ber of your device. The serial number starts
with three letters (e.g. ANK675A2A2).

After the successful registration (See de­tails in “Free Registration of your Test In­strument“ later in this user manual) of your
AL1 the start-up screen may be customized
(See details in “Customizing the Start-up
Screen” later in this user manual).

Menu Bar

Use the menu bar to select the basic test congurations.

Measurement
Functions

Screen
Selector

Input
Filters

Setup
Screen

Memory Menu
& Battery Status
Indication

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Measurement Functions

Screen Selector

• SPL/RTA: SPL & RTA measurement

• RT60: Reverberation Time

• FFT: Real time zoom FFT

• Polarity: Speaker polarity

• Delay: Delay time

• RMS/THD: RMS level and distortion

• STI-PA: Speech intelligibility

• Calibrte: Calibration menu

The SPL/RTA, RT60 and STI-PA
measurement functions can be viewed in
two test result screens.

For example, the SPL/RTA “123” selector

displays the sound level meter screen
while the bargraph symbol selector
displays the real time spectrum analyzer.

Short-cut

Hold the ESC button down and
simultaneously press the left or right arrow
key to switch between the two display
screens within the same measurement
function.

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Input Filters

Depending on the selected measurement function the following sets of

lters are available:

SPL/RTA function:

Filters Applications
FLAT

Flat frequency response

(no ltering)

A-WTD

A-weighting lter in

accordance with IEC 61672

C-WTD

C-weighting lter in

accordance with IEC 61672

X-CRV

-1

Inverted X-Curve lter in

accordance with ISO 2969

RLB (Revised Low­frequency B-curve)

Broadcast Loudness

lter in accordance with

AES Paper “Loudness
Assessment of Music and
Speech” 2004

Overall sound pressure level; all
sound signal components are included
without weighting - required for special
applications.

Applicable to most common sound
pressure levels if level weighting
compensation for human loudness
perception is required.

Applicable to higher sound levels if level
weighting compensation for human
loudness perception is required.

Required for cinema installations

Applicable for loudness measurement
of broadcast material. The revised
B-weighted Leq measurement (RLB)
has the best correlation to the subjective
experience of humans.

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RMS/THD function:

Filters Applications
FLAT

Flat frequency response

(no ltering)

A-WTD

A-weighting lter in

accordance with IEC 61672

C-WTD

C-weighting lter in

accordance with IEC 61672

HP400

Highpass 400 Hz in
accordance with DIN 45045,

-120dB/dec.

HP19k

Highpass 19 kHz

Overall sound pressure level; all
sound signal components are included
without weighting - required for special
applications.

Applicable to most common sound
pressure levels if level weighting
compensation for human loudness
perception is required. For example,
measuring residual noise of a device in
sound broadcasting applications.

Applicable to higher sound levels if level
weighting compensation for human
loudness perception is required - for
special applications.

Removes any mains frequency (50/60Hz)
components from the test signal.

Removes any low frequency components
from the test signal, e.g. to measure
critical public announcements systems
with no audible change to the signal
(using a 20kHz pilot tone level)

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Setup Screen

The setup screen allows customization of
basic settings of the Acoustilyzer AL1:

• Move the cursor to the corresponding
eld and press the enter key.

• Select the required status using the

arrow keys.

• Press the enter key to conrm.

AUTO POWER OFF denes the time period, after the last keypress, after

which the AL1 is switched OFF automatically. The available settings are
3 MIN, 10 MIN, 30 MIN, 60 MIN and DISABLE. If DISABLE is selected,
the user has to turn the unit off manually or it will run until the batteries
are discharged.

AUTO LIGHT OFF denes how long the backlight stays on after any key

stroke. Possible selections are 3 SEC, 10 SEC, 60 SEC and DISABLE.
If DISABLE is selected, the backlight will stay on until the unit is switched
off. Note that the backlight reduces the lifetime of the batteries.

Acoustilyzer operation with MiniLINK PC Software

During the operation of the AL1 with the MiniLINK PC software, the AL1
is powered from the PC and the “Auto Power Off” and “Auto Light Off”
power-saving functions are disabled. After the PC software MiniLINK
is closed, and until the USB cable is disconnected, the Acoustilyzer
continues to be powered from the PC but these power-saving features
are again enabled.

LCD CONTRAST adjusts the contrast of the display. Alternatively, hold

the ESC button down and simultaneously press the up/down arrow key
while in any measurement function.

MULTIPLE SETUP allows storage of up to four individual settings. To

enable the multiple setup mode, set the corresponding entry to ENABLE

and conrm. The next time the Acoustilyzer is switched on, the user will

be prompted to select the individual setup-ID (1, 2, 3 or 4) in the start­up screen. All parameter settings in all measurement functions are now
stored under this ID at switch off.

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Memory Menu & Battery Status Indication

All measurements can be stored into the
internal instrument memory. Each record is

saved with a le name consisting of the test

mode and a continuous running number
from 000 - 999, such as “A001_RMS_THD”
or “A002_RT60”. After 999 the running
number starts again with 000.

You can store the test results as follows:

• STORE+BMP

Saves the numeric test results including
the graphical screenshot, indicated by
BMP (bitmap), in the memory overview.

• STORE

Saves the numeric test result only, thus
occupying less memory space.

• VIEW+DELETE

The stored measurement results are
listed in decending order, so the latest
recorded measurement is always on top
of the list. The remaining memory space
is displayed in the right-upper corner of
the screen.

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All screenshots marked with BMP can be
reviewed directly on the instrument.

• Select any record in the list using the

cursor.

• Press and hold the enter key.

• The recorded measurement is displayed

on the instrument screen

• The selected record is marked in the

memory menu with the shaded square
on the left. You can recall the marked
record at any time later by holding down
the ESC button and simultaneously
pressing the enter key.

Delete individual memory records

Individually stored results can be deleted
from the memory.

• Select the DEL eld beside the memory

location to be deleted.

• Select OK within the pop up window and

press the enter key.

• The memory location is deleted from the

device memory.

Delete all memory records

The complete memory can be deleted by

selecting the eld “DEL ALL“.

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LOAD

Various Acoustilyzer functions support test
result data loading from the internal AL1
memory. This feature is useful for reviewing
test results of measurements previously
stored on the test instrument.

The following measurements support this
feature:

• SPL/RTA

• RT60

• FFT

• STI-PA

Note: Any ongoing measurement is

continuing during loading and
viewing of a previous test result.

Application example using SPL/RTA:

• Select LOAD in the memory menu and

press enter.

• The data available for loading is

displayed.

• Select the test result of interest.

• Conrm the selection with the enter key
→ the square symbol on the left of the

selection is shaded.

• Press the ESC button (cursor jumps to
OK) and conrm with enter.

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The loaded test result is displayed on the
active AL1 screen and the abbreviation LOD

ashes in the status bar memory eld.

The individual band levels can be viewed,
the Y-axis altered or even the Leq or min/
max test result shown.

Return to the live mode by selecting LIVE
MODE in the memory menu of the upper
menu bar.

Low battery indication

A low battery symbol is displayed in the

“MEM” eld of the menu bar when a change

of batteries is required.

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4. Measurement Functions

Overview

Test

Function

SPL/RTA

RT60

FFT Real-time Zoom FFT
POLARITY Polarity Test

DELAY Delay Time

RMS/THD

STI-PA

CALIBRTE Calibration Menu

Result

Screens

Test Features

Sound Level Meter

Sound pressure level SPL, MAX/MIN SPL, Leq,
LCpeak

Real Time Analyzer

1/1 and 1/3 octave real time spectrum analyzer
showing SPL, MAX/MIN SPL & Leq per band

Reverberation Time

in octave band resolution based on T20 results

Reverberation Time

detailed test results listed in seconds, including
correlation factor

of acoustic speaker or electrical line signals

Propagation delay measurement between
electrical reference and acoustic signal

Electrical Measurements

Level RMS, THD+N, Frequency

Speech intelligibility

with STI or CIS values. Visible after STI-PA

license key has been activated

Speech intelligibility

Individual Leq and STI-PA modulation indices of
test frequency bands

for external measurement microphones,
sensitivity set by default to NTi Audio MiniSPL

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SPL/RTA - Sound Level Meter

The Acoustilyzer features a comprehensive, integrating sound level meter
with timer for single or repeated measurements. All results may be logged
into the internal memory for further review.

The measurements displayed on the big and small result position may be
chosen among

• SPL Actual sound pressure level

• MIN SPL Minimum sound pressure level

• MAX SPL Maximum sound pressure level

• Leq time-averaged sound pressure level

• PreLeq Leq of the previous timer period (only available

when timer is in repeat mode

• LCpeak C-weighted peak sound pressure level

The Timer can be congured to

• Stop the Leq, LCpeak and MAX/MIN SPL measurements after a

user-dened time period

• Reset the Leq, LCpeak and MAX/MIN SPL measurements after a

user-dened time period in order to start a new measurement

Big Result

Small
Result

Timer
Status

Input Range
indicator arrows

Pause Measurement

SPL Bargraph and range
indication

Reset Test Cycle

Period

Time Weighting
indicator / selector

Timer, Clock

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Test Applications: “Timer Status” Setting

TIMER OFF

(applicable for standard measurements)
All values are recorded and monitored
continuously. The measurement timer
shows the actual testing period length.
Pressing the RESET icon sets the clock
and the test results back to zero.

TIMER SINGLE

Sound pressure level measurement with

user-dened time setting.

• Set the required test cycle period.

• The clock counts back to zero. After the
dened test time is completed, the clock
ashes ”00.00.00”.

• The test results Leq, LCpeak and MAX/

MIN SPL are frozen.

• Changing the test cycle period setting

or pressing the RESET icon restarts the
measurement.

TIMER REPEAT

Automatically repeat measurements with

user-dened test time interval.

• Set the required test cycle period.

• The measurement timer counts back to

zero. When the test time has elapsed ,
the clock and the test results are reset
and a new measurement is started.

• The previously measured Leq is

displayed as PreLeq (useful for Leq
monitoring at live concerts)

• Changing the test cycle period or

pressing the RESET icon restarts the
measurement.

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Pause: The Leq, LCpeak and MAX/MIN measurements can be paused

• Select the PAUSE symbol and press the enter key.

• The PAUSE symbol ashes.

• The actual SPL value is continuously measured and displayed.

• Select the pause symbol and press the enter key to continue the

measurement; the clock continues to count.

Reset: Pressing the RESET icon restarts the measurement. The timer and

test results are reset.

Test Cycle Period: Applicable in SINGLE and REPEAT timer status only.

• SINGLE: Set to 10 min by default

• REPEAT: Set to 10 sec by default

Measurement Timer: Actual measurement in hours:minutes:seconds.

Big and Small Result: Two of the previously-listed measurements may be

display at the same time.

Time Weighting: All SPL measurements (SPL and MAX/MIN SPL)

are time-weighted measurements. Changes in the SPL level are
smoothed, resulting in quicker or slower change of the displayed value.
Available time weightings, corresponding to IEC 61672, are

• SLOW (long attack and release response time, t = 1s)

• FAST (short attack and release response time, t = 125ms)

The time weighting for the broad band values ( ) and the RTA ( )
are always the same.

Overload

The OVL (Overload) ashes if the input

voltage exceeds the selected input range
of the instrument. As long as the OVL is

ashing the displayed Leq and LCpeak

results are not accurate.

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Input Range Selector & Bargraph

In the SPL/RTA Mode the AL1 has three measurement ranges (RNGE).
The span of each range depends on the sensitivity of the microphone
used. For a MiniSPL with a sensitivity of 20mV/Pa the measurement
ranges are:

20 to 100 dB 40 to 120 dB 60 to 140 dB

The selected input range is displayed at the bottom of the bargraph and
may be changed by operating the range indicator arrows. The bargraph
provides an analog display of the actual sound pressure level.

Primary Indicator Range

To achieve best measurement accuracy the appropriate range,

called the “primary indicator range”, must be selected. Correct setting

avoids overow indications and lowers the inuence of noise on the

measurement result.

The two range indicator arrows assist the user to set the optimal range.

As soon as the indicated bargraph value is found lower than the primary
indicator range, the down arrow symbol below RNGE will start to move,
symbolizing that the actual SPL measurements are inaccurate. The
bargraph range needs to be changed manually by selecting the moving
left arrow symbol and pressing the enter key.

Note: Changing the ranging resets all ongoing measurements.

When exceeding the primary indicator
range, three overload arrows replace
the big result reading.

• Select the right arrow below RNGE
and press enter to change to the next
higher bargraph range.

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SPL/RTA - Real Time Analyzer RTA

The Acoustilyzer sound level meter features 1/3rd or full octave band test
results using class 0 lters. The SPL, MAX / MIN and Leq values are
displayed per band.

Stored spectra may be averaged by using the available mathematical
functions. The MAX-MIN display is particularly helpful for characterizations
of listening areas.

Set
Menu

Audio
Spectrum

Input Range
indicator arrows

Pause Reset Cursor

Readout

X-Axis with manual
range selection

Y-Axis

The audio spectrum is displayed without interrupting any ongoing sound
level measurements, so e.g. changing from to screen will not
interrupt the ongoing sound level measurements.

Input Filter

The SPL/RTA input lter for the broad band values ( ) and the RTA ( )
may be selected independently - so e.g. a FLAT RTA is available while the

broad band values are acquired using an A weighted lter. Please note that
only various lter combinations are possible.

Note: Changingltersettingsre-startstheongoingmeasurement.

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Set Menu

The SET menu provides access to
measurement settings and display options
as listed below:

RES - Resolution

Select 1/3rd octave or full (1/1) octave band
resolution by pressing the enter key.

SHOW - Test Result

The actual SPL, MAX/MIN SPL and Leq
can be displayed per band.

The actual SPL is displayed with lled

bars.
The Leq spectrum is displayed with framed

bars.

The MAX/MIN SPL range is displayed with

lled bars. The cursor readout shows either

the maximum, the max-min difference or
the minimum sound pressure level of the
selected band.

Simply toggle through these results with
upper & lower arrow keys:

- max. SPL

- min. SPL

- max. - min. SPL