to explain what the graphs show....
sensor is collecting data at 500Hz, i.e. every 2ms
The app analyses, by default, this data to yield a frequency resolution of approx 1Hz. In order to achieve this, we need 512 (a power of 2 value is used for various reasons) samples, i.e. approximately 1s of data. This means every line drawn on the RTA is the result of 1s worth of measurements.
However the recorder is streaming this data to recorder in real time, it is configurable but by default it will send about 8 samples at a time (the way the data is transmitted means this is about enough to fill a single packet hence making efficient use of the network). The analyser therefore receives about fresh data every ~16ms. This equates a refresh rate of about 60Hz so if we wanted to maintain this refresh rate on screen, we'd need to complete the analysis & push the data to the screen in under 16ms. I don't think this is likely to be achievable in general so the analyser has a config option for a target refresh rate. By default, this is set to 20Hz (which gives us 50ms to process the data and update the screen). The analyser therefore snaps data every 50ms, runs it through the analysis and pushes it to the screen.
i.e. every time the curve updates in the RTA, it represents about 50ms of data
In the video above I show the average & peak views and the hold time is set to 2s. This means we take the last 2s worth of snapshots (which were taken every 50ms) and average them (at each frequency) and calculate the peak (at each frequency) for the peak.
i.e. we have 40 (2s / 50ms = 40) separate magnitude response curves which are averaged or max'ed to produce the graph shown above.
If you show the live view then you're always just seeing that latest snapshot (i.e. the last 50ms of data).
This applies to all analysis types (avg, peak and psd). Note that avg is equivalent to the A in a PvA (in BEQD) and peak is the same as the P in a PvA (in BEQD) so if you're comparing to the source track then remember to compare to the right target curve depending on whether you're looking at avg or peak (PSD is slightly different so isn't directly comparable).
-> pushes data to the analyser every 16ms
-> every 50ms analyser calculates avg/peak view for data that has arrived since the last snap (i.e. the last 50ms of data if everything is keeping up)
-> graph updates