infrasound measurement

[jschwender]

It would be very nice if sweep can start from 0.01 Hz on. infrasound measurements are currently limited, as below 20 Hz there are a lot of artefacts, and nothing is displayed below 2 Hz. A longer measurement time would also be helpful. Is that possible to do, or does it causes problems in REW or is this requirement too exotic?

 

[John Mulcahy]

If you set the sweep start to less than 20 Hz it will start at 0 Hz (see Measurement sweep). In the current build the frequency axis start can be changed in the View preferences, down to 0.1 Hz minimum. The longest sweep is 4M, which takes 87 s at 48 kHz sample rate. If you use a long sweep and want to look at very low frequencies you will need to make sure you retain enough (or all) of the IR (see the Analysis preference for IR truncation) and set a suitably long right hand IR window.

 

[jschwender]

Dear John, thank you very much. That combination did it, now i trust what i see. Thanks!