Nearfield sub measurements overdrive REW's input

[cvanc]

Hi all, I'm taking sub measurements very near the cone so SPL levels into REW are hitting & exceeding 114dB. I'm not sure if I need to adjust REW's input range or adjust my USB mic's gain? It's a UMIK-2.

(trying to measure THD while very loud - I'm hunting down one misbehaving sub)

Thanks!

 

[John Mulcahy]

You can try setting the Windows mic level to 50% (approx -10 dB) to avoid clipping the digital data but you still might run into internal clipping in the mic.

 

[cvanc]

UMIK-2 is rated to 125dB, as soon as I plug it in REW reports max input SPL of 114dB.

I'm in the extreme nearfield so I'll fix my issue just by backing the mic away. But for the record, can I do anything about that 114dB limit and nudge it up to the limit of my particular mic? Thanks.

 

[John Mulcahy]

You would have to change the mic's internal analog gain and adjust the cal file sens factor accordingly. I don't have instructions for how to do that, sorry.