VT USA-168A/B Real Time Underwater Sound Analyzer Manual Rev. 1.5
www.virtins.com 10 Copyright © 2021-2022 Virtins Technology
Virtins Technology
Now, if you start the oscilloscope by pressing the red button at the upper left corner of the
screen, and then talk LOUDLY before the hydrophone, you should be able to see your
“voices” in the Oscilloscope and Spectrum Analyzer.
Some Windows versions / editions come with some audio signal enhancement features which
are enabled by default. These features must be disabled through the Sound Recording Control
under Windows Control Panel to prevent them from altering the originally sampled data, as
shown below. One of the possible problems caused by these features is the unwanted
alteration of the frequency response of the setup. Using ASIO driver instead of MME driver
can avoid these problems. It should also be noted that when MME driver is used, the actual
sampling rate is determined by the sampling rate configured in the Sound Recording Control
Panel (see figure below). If the sampling rate selected in Multi-Instrument differs from the
actual one, then sampling rate conversion will be performed automatically by Windows and
this will alter the original data unwantedly.
1.4.3.2 Configure Sound Playback Devices for Multi-Instrument
The Signal Generator of Multi-Instrument can be used for sound playback and generation.
You can use it to playback a recorded underwater sound, or generate an underwater test
sound if you have an underwater sound emitter attached. To configure the sound card for the
Signal Generator, go to [Setting]>[DAC Device]. Either “Sound Card MME” or “Sound
Card ASIO” can be chosen in the “Device Model” field. Choose the corresponding sound
card’s name in the “Device No.” field. By default, the XLR-to-USB sound card with its
ASIO driver is selected for signal output.
