Triggered Record Using WAV File and 6 Mic Array Test Sequence
A test sequence ideal for measuring in-car audio systems
This sequence allows you to measure a playback system without analog inputs using a 6 microphone array. Specifically, the sequence is designed to measure an in-car audio system. A stimulus WAV file is created in SoundCheck and transferred to the device under test (DUT) where it is played back and the response captured by SoundCheck using a triggered record function. The 6 recordings are batch analyzed to produce individual fundamental curves and the curves are post-processed to produce a single average curve from which an average sensitivity value is calculated.
The default stimulus WAV file may be customized in the stimulus editor. The default stimulus is a stepped sine sweep from 20 kHz to 20 Hz with R10 (1/3 octave) resolution. The stimulus can be saved as a WAV file from the memory list and also during the sequence run, if desired. This file will have the same sample rate and bit depth as the audio interface (in this case, 44.1kHz, 24 bit). By default, the WAV file is automatically normalized to 0 dB FS in the autosave step, so the stimulus level is not important. Note that:
- The parameters of the sweep in the stimulus step are used when creating the WAV file.
- The duration of this stimulus must be considered in the “Time” field of the acquisition step.
- The stimulus step must remain in the sequence and the stimulus settings cannot be changed without re-generating the WAV file with the updated parameters.
- The default stimulus WAV file used in this example is included in the sequence folder.
- Changing the sample rate or bit depth of your audio interface also requires re-saving the WAV file.