Yeah ... meters usually are not spec'ed to be accurate below 30 Hz ... and then they only usually offer A or C weighting ... which I think is aimed at measuring work place noise ...

The A weighting, I believe, displays the relative loudness we actually hear (i.e. compensated for human hearing). C weighting is the most used and I have no idea why but it's closer to flat. Z weighting is absolutely flat and is the one I'm interested in but seems to be offered only in the most expensive models ...

So I'd imagine it's best to measure using C weighting and convert back to flat. C rating is something like -0.5db at 80Hz, -2db at 40Hz, -6.2db at 20Hz, and -8.5db down at 16Hz (compared to A which is -22.5, -34.6, -50.5, -56.7 respectively) ... if your device is capable of measuring it.

Think someone who knows more should respond here.

Rich

P.S. That's probably why your subs were a bit hot ... BTW C is 0db down at 200Hz and if your sub can get up there that's the frequency to use (also 160Hz is only 0.1 db down)

Last edited by rrlev; 12/03/19 11:19 PM.