What is Magnitude Thresholding?

What is Magnitude Thresholding?

You may be familiar with Coherence threshold blanking within Smaart, but did you know that there is another way that you can threshold data within Smaart?

Magnitude Thresholding, much like Coherence Blanking, is a setting within Smaart that allows you to eliminate less useful information from your measurements. While coherence blanking is set as a percentage, Magnitude Thresholding is set in terms of Full Scale (dBFS). Once set to a nonzero number, Smaart will zero out frequency data at any point where the reference signal is below the threshold prior to factoring it into the Transfer Function measurement. By default, this is set to -70 dBFS. This can be changed under the Transfer Function tab in the Measurement Settings dialog, and can be disabled by entering 0.

While both are considered types of "thresholding," it is important to note that Coherence thresholding occurs post-process, only affecting the presentation of data, not the data itself. On the other hand, Magnitude Thresholding occurs pre-process, affecting how much information is let into the dual-channel measurement to begin with.

This setting not only exists within Transfer Function mode, but in IR mode, as well. Here, it can be adjusted under the Impulse Response tab of the Graph Settings dialog.

Much like in TF mode, Smaart will zero out the transfer function at any frequency the reference signal does not cross the threshold before calculating the (dual-channel) impulse response. Unlike in TF mode, it is set to 0 by default, rendering it inactive until set to a nonzero dB FS value.