Virtins technology RTA-168C User manual

VT RTA-168C Manual Rev. 1.5
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Virtins Technology
VT RTA-168C Manual
A Real Time Acoustic Analyzer, Sound Level Meter, Distortion Analyzer,
Polarity Tester, …
Note: VIRTINS TECHNOLOGY reserves the right to make modifications to this manual at any time without
notice. This manual may contain typographical errors.

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TABLE OF CONTENTS
1 INSTALLATION AND QUICK START GUIDE..........................................................................................3
1.1 PACKAGE CONTENTS....................................................................................................................................3
1.2 HARDWARE CONNECTION DIAGRAM............................................................................................................4
1.3 HARDWARE DRIVER INSTALLATION.............................................................................................................5
1.4 MULTI-INSTRUMENT SOFTWARE INSTALLATION AND CONFIGURATION.......................................................5
1.4.1 Install Multi-Instrument.......................................................................................................................5
1.4.2 Start Multi-Instrument..........................................................................................................................5
1.4.3 Configure Multi-Instrument.................................................................................................................7
1.5 INPUT OF SOUND LEVEL CALIBRATION DATA AND ADJUSTMENT OF INPUT GAIN........................................9
1.5.1 Under Windows XP or a Windows Version Before XP ......................................................................10
1.5.2 Under Windows Vista.........................................................................................................................10
1.5.3 Under Windows 7...............................................................................................................................11
1.5.4 Under Windows 8/8.1/10....................................................................................................................13
1.5.5 0dB Reference Vr...............................................................................................................................14
1.6 MICROPHONE FREQUENCY COMPENSATION ...............................................................................................14
1.7TWENTY MOST FREQUENTLY USED MEASUREMENT SETTINGS .................................................................17
1.8 MORE ACOUSTIC ANALYSIS FUNCTIONS AVAILABLE IN MULTI-INSTRUMENT PRO OR ABOVE..................20
1.9 LIST OF AUDIO TEST WAV FILES (AUDIOTESTCD.ZIP) .............................................................................20
1.10 OPERATION NOTES ...................................................................................................................................22
2 SPECIFICATIONS.........................................................................................................................................23
2.1 HARDWARE SPECIFICATIONS......................................................................................................................23
2.2 MULTI-INSTRUMENT SOFTWARE SPECIFICATIONS......................................................................................24
3 MULTI-INSTRUMENT SOFTWARE LICENSE INFORMATION ........................................................33
3.1 LICENSE TYPES...........................................................................................................................................33
3.2 LICENSE UPGRADE FROM ONE LEVEL TO ANOTHER...................................................................................33
3.3 SOFTWARE UPGRADE IN THE SAME LICENSE LEVEL...................................................................................33
4 WARRANTY...................................................................................................................................................33
5 DISCLAIMER.................................................................................................................................................34

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1 Installation and Quick Start Guide
1.1 Package Contents
A standard VT RTA-168C Package contains the following items:
1) USB Measurement microphone and its accessories (a windshield, a microphone clip and
stand)
2) USB cable (3 m)
3) CD (containing the copy-protected Multi-Instrument Software)
The latest software can always be downloaded from www.virtins.com/MIsetup.exe.
4) USB hardkey (containing a Multi-Instrument Standard License)
5) Audio Test WAV files (containing a list of audio test tones and noises)
They can be downloaded at: www.virtins.com/AudioTestCD.zip and then burnt into a CD
or saved into a USB memory stick. They can also be generated directly from the Signal
Generator of Multi-Instrument.
6) 1/8” TRS cable (1.8m)
USB Measurement Microphone
Windshield
Microphone Clip and Stand

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7) Black Soft Pouch Case
8) Unique Sound Level Calibration Data (in CD)
9) Unique Microphone On-Axis and 90-degree Calibration Data (in CD)
1.2 Hardware Connection Diagram
Connect the corresponding ends of the USB cable to the USB measurement microphone and
a PC’s USB port. When this is complete, the blue LED lights up indicating that it is receiving
power.
Software Activation
The USB hardkey needs to be plugged into any USB port of the PC in order to activate the
Multi-Instrument software. Otherwise the software will run under the 21-day fully functional
free trial mode before the trial period expires.
Test Signal Generation
You can generate the test signals from the Signal Generator of Multi-Instrument. The USB
measurement microphone does not have any audio output channels, so you need to use your
computer’s built-in sound card or any other sound card for audio test signal output. The
quality of the test signals would depend on the sound card used. Generally, the built-in sound
card of a laptop is good enough for generating quality test signals for magnitude frequency
response measurement of an audio system.

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The 1/8” TRS cable provided in the product package can be used to connect the sound card’s
audio output (e.g. Line Out, Headphone, Speaker) to the AUX input of the audio system
under test.
Alternatively, you can play the test signals from an audio CD or a memory stick.
1.3 Hardware Driver Installation
No hardware driver installation is required. It is supported by Windows natively.
1.4 Multi-Instrument Software Installation and Configuration
Multi-Instrument is a powerful multi-function virtual instrument software. It supports a
variety of hardware ranging from sound cards which are available in almost all computers to
proprietary ADC and DAC hardware such as NI DAQmx cards, VT DSOs and so on. It
consists of multiple test instruments such Oscilloscope, Spectrum Analyzer, and Multimeter,
etc.
1.4.1 Install Multi-Instrument
Insert the Multi-Instrument installation CD into your computer’s CD-ROM drive and follow
the instruction on the screen to install the Multi-Instrument software. The installation file
can also be downloaded from www.virtins.com/MIsetup.exe.
1.4.2 Start Multi-Instrument
To start Multi-Instrument, on the Windows desktop, select [Start]>[All Programs]>[Multi-
Instrument]>[VIRTINS Multi-Instrument], or simply double click the MI icon.
If the software is started for the very first time after installation, it will prompt the user to
select a default device (see figure below). Select VT RTA-168C according to the hardware
device to be used.

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The default device can also be changed later via [Setting]>[ADC Device], [Setting]>[DAC
Device], and [Setting]>[Configure Hot Panel Setting Toolbar], or simply [Setting]>[Restore
to Factory Default]. However, if [Restore to Factory Default] command is executed, all
calibration data entered manually via [Setting]>[Calibration] after software installation
will be reset to the default values of the selected product. To avoid the loss of the
manually entered calibration data, you can save them as a calibration file first.
Otherwise, you will have to enter the unique calibration data that come with the
product package again.
After the default device is selected, the software will prompt the user to select a default color
scheme (Skin). The default skin can also be changed later via [Setting]>[Display].

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The main window of the software will open after the above skin selection. The following
figure shows a typical screen layout (obtained by clicking the “OCT3” button in the Hot
Panel Setting Toolbar after the launch of the software). Please refer to the software manual
for detailed functions of the software. The software manual can be accessed via [Start]>[All
Programs]>[Multi-Instrument]>[VIRTINS Multi-Instrument Manual] (in PDF format) or
[VIRTINS Multi-Instrument Help] (in HTML format) on Windows Start menu, or
[Help]>[Software Manual] or F1 inside the software.
1.4.3 Configure Multi-Instrument
In Multi-Instrument, the menu items are enabled/disabled based on context. Many menu
items are disabled when the Oscilloscope or the Signal Generator is running. To do the
configuration, stop the oscilloscope first by pressing the green button at the upper left corner
of the screen (see figure below). The button will turn red once the Oscilloscope is stopped.
1.4.3.1 Configure Sound Recording Devices for Multi-Instrument
Go to [Setting]>[ADC Device], and choose “Umik-1” , “Microphone (Umik-1)” and the like
in the “Device No.” field (see figure below). This is to configure the USB measurement
microphone Umik-1 as the sound recording device for the software. Note that the displayed

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name of the USB microphone may vary a bit under different Windows versions. The
“Device Model”field must be set to “Sound Card MME”.
Under Windows XP or a Windows Version Before XP
Under a Windows Version after XP
Now, if you start the oscilloscope by pressing the red button at the upper left corner of the
screen, and then talk before the measurement microphone, you should be able to see your
“voices” in the Oscilloscope and Spectrum Analyzer.
1.4.3.2 Configure Sound Playback Devices for Multi-Instrument
The USB microphone does not have any audio output channels, but you can use your
computer’s built-in sound card or any other sound card for audio test signal output, if you
want to use the Signal Generator in Multi-Instrument to generate the test signals. To
configure the sound card for the Signal Generator, go to [Setting]>[DAC Device] and choose
the corresponding sound card’s name in the “Device No.” field. By default, Multi-

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Instrument will use the computer’s built-in sound card for signal output. Again, the “Device
Model”field must be set to “Sound Card MME”.
Now, if you press the Signal Generator button (see figure above), the Signal Generator panel
will be opened (see figure below). Press the red triangle button at the upper right corner of
the Signal Generator panel, you should hear a 1kHz test tone from the speaker or earphone
connected to the selected playback sound card. Press it again to stop the sound.
1.5 Input of Sound Level Calibration Data and Adjustment of Input Gain
Sound Level Calibration is not required for those relative measurements such as frequency
response, THD, THD+N, IMD, etc.. It is required only if you want to measure the absolute
sound level.
The USB measurement microphone has been calibrated in the factory. The sound level
calibration data are provided in a separate sheet inside the product package. Please refer to
the calibration data sheet provided and enter the calibration data in the respective highlighted

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fields in the Calibration Setting dialog box (see figures below). Note that different calibration
data are required for different Windows versions. The Calibration Setting dialog box is
opened via [Setting]>[Calibration] in Multi-Instrument.
You can adjust the sound level measurement range by adjusting the input gain of the USB
sound card through software.
1.5.1 Under Windows XP or a Windows Version Before XP
Input of the Sound Level Calibration Data
Note the calibration data in the following figure are examples only, you should enter the
actual calibration data provided inside the product package.
Adjustment of Input Gain via Software
Under Windows XP or a Windows version before XP, the input gain of the USB microphone
is not adjustable. Neither the Recording Control under Windows Control Panel nor Multi-
Instrument can adjust the input gain.
1.5.2 Under Windows Vista
Input of the Sound Level Calibration Data
Note the calibration data in the following figure are examples only, you should enter the
actual calibration data provided inside the product package.