Complete Test Sequence
The purpose of this sequence is to perform a full suite of basic measurements for a loudspeaker
The purpose of this sequence is to perform a full suite of basic measurements for a loudspeaker. A 500 mV stepped sine sweep from 20 kHz to 50 Hz is played through the speaker and measured via two channels of the audio interface. A calibrated reference microphone is connected to one of the channels, and an impedance reference is connected to the other.
A HarmonicTrak™ analysis step analyzes the recorded waveform from the reference microphone, and outputs frequency response, THD, Rub & Buzz, and various harmonic curves. A second analysis step analyzes the waveform from the impedance reference and outputs a curve of impedance versus frequency. A post processing step is used to estimate the characteristics of the impedance curve and calculates the max impedance, resonance frequency, and the Q of the resonance peak.
A series of limit steps are placed in the sequence with arbitrary values simply to show how these steps could be used. You may wish to enter new limit values based upon the device you are testing.
- Audio Interface – Listen AudioConnect or similar
- Amplifier – Listen SCAmp or similar
- Reference Microphone – Listen SCM-3 or similar
- Impedance Reference – Listen Impedance Box or SCAmp impedance reference output
Hardware Setup and Calibration
- Calibrate the amplifier as instructed in the SoundCheck manual.
- Calibrate the reference microphone as instructed in the SoundCheck manual.
- Connect output 1 of the audio interface to the input of the amplifier.
- Connect the impedance reference (connection types will vary depending on reference type).
- Connect the amplifier output to the loudspeaker.
- Position the reference microphone at the desired test distance from the loudspeaker, and connect it to the microphone power supply.
- Connect the output of the mic supply to input 1 of your audio interface.
- Connect the output of the impedance reference to input 2 of your audio interface.
This sequence is included in the Sequences folder of your SoundCheck installation.