Main window : File > Sound Card Settings
This dialog box allows adjusting the sound card settings.
The Sampling Frequency should be accommodated to the signals to be analyzed. It should be at least twice the maximum signal frequency to be recorded.
Note that the sampling frequency also influences the frequency resolution of spectrograms and spectra. The absolute frequency resolution (expressed in Hz) is inversely proportional to the sampling frequency. For that reason (and in order to save storage space) it is recommended to use the lowest sample rate that satisfies the Nyquist criterion.
The Number of Bits listbox sets the sampling resolution to either 8 or 16 bits (use always 16 bits unless there are good reasons to use 8 bits only). The Stereo option will record from 2 channels (left and right) rather than only from one channel (left).
The option Down-sampling by allows to down-sample the incoming data in real-time, which can be useful for recording low-frequency signals whose signal frequencies are much lower than 2000 Hz.
If the option Duration of Recording is activated, each recording will be stopped when the specified duration has elapsed. Otherwise, the recording process must be stopped manually (it will also stop automatically once the file size has reached 2 GB).
If the option Perform off-line Sampling Frequency conversion is activated, the original waveform data provided by the soundcard (at the sampling frequency selected above) is re-sampled after recording has finished using the parameters set on the
dialog box Edit > Sampling Frequency Conversion...,
which allows creating sound files at sample rates not directly supported by the soundcard.
The edit field Overload if sample>= determines the overload threshold of the overload detecting mechanism.
Active audio input Select here the sound card or audio interface that should be used for recording.
The option record from the RECORDER software ring buffer allows to record from devices that are not directly supported by the SASLab Pro software, such as Avisoft-UltraSoundGate or National Instruments DAQ devices. To enable this mode of operation, the corresponding RECORDER software ring buffer file must be selected either by the ring.wav button or by drag and drop into the Sound Card Settings dialog box. On the RECORDER software, the ring buffer must have been setup from the command
Monitoring > Ring buffer...
and the monitoring must be running.