waterfall measurement

[Alpi]

How loud should you measure for a waterfall measurement?
70, 75, 80, 85db.....?
How does the volume affect the measurement?

thanks

 

[John Mulcahy]

75 dB is plenty, it is also fine to measure at lower levels. Measuring at higher volumes means the noise floor is further below the rest of the measurement. The noise floor can also be reduced by keeping the volume the same and using a longer sweep. However, the noise floor is not a relevant part of a waterfall measurement.

The shape of the result should not be affected by the volume level, unless it is so low that external noise becomes dominant or so high that distortion and thermal effects change the loudspeaker behaviour.

 

[Alpi]

Thank you!
How meaningful is the waterfall measurement below 200Hz?

 

[Wayne A. Pflughaupt]

Very. That’s actually the only range where waterfalls are relevant.

Regards,
Wayne

 

[Alpi]

Thanks