Loudspeaker and Electroacoustic Test Products
Sonic beacon is a PC-based test and
measurement system for the testing of loudspeakers and other
electro-acoustic products using commercially available Windows multimedia
sound cards. Sonic beacon will perform Frequency and Phase Response,
Harmonic and Intermodulation Distortion, Polarity, Impedance, Sensitivity
and SPL as well as other FFT and Real Time Analysis tests, Sixteen bit
sampling rates up to 192 kHz and FFT lengths up to 128K points are
Sonic beacon contains six different virtual instruments that
can be cascaded in order to form a process. An input signal emanating
from a WAVE audio file, the Signal generator or a sound card may be
passed serially from one module to another. Each module performs a
process on this signal and alters its time or frequency domain
representation. If the modules are coherently cascaded a sensible
analysis can be done on the input signal.
It also contains a unique calibration algorithm that allows
for the compensation of input level, latency and frequency response
errors in personal computer sound card electronics. These calibrations
may be saved to a file and subsequently recalled and applied to any new
process that uses the sound card.
Multiple process streams may be opened within the
application and will execute simultaneously. Multiple instances of the
application can also be opened. Data may be transferred to and from
instances of the application, processes, text editors and spreadsheets
using the Windows clipboard. Modules may be added or deleted at any point
in a process stream and all existing instruments, in the process, will
retain their current settings. Process streams may be saved to disk and
all instruments will retain their current settings, size and location when
Any module with a display screen may be previewed or
printed. Debugging options include Pause on Every Module and Pause On
Every nth Record.
The following virtual instrument modules are available
1. WAVE File Open
Module: Opens a PCM file and converts it data to the internal FFT
records required by the processing application.
Signal Generator Module: Outputs a variety of wave shapes at
frequencies from 0 Hz to one half the current sample rate.
Arbitrary Filter Module: A digital filter with an arbitrary,
programmable amplitude and phase response.
Oscilloscope Module: An oscilloscope module that displays two
channels of time domain data
Spectrum Analyzer Module: A two channel Spectrum Analyzer module
that can perform FFT’s, Cross Correlations and FHT’s Transforms on time
DataLogger Module: A color keyed, persistent plotting engine that
can display data in either the time or frequency domain.
SoundIO Module: Records and plays audio signals on any PC sound
card that is compatible with Windows multimedia services
WAVE File Save Module: Converts digital signal data generated by a stream
of process modules to RIFF and saves it to disk as a PCM Waveform audio