SPL Surprise!


Recently during a listening session, I got the idea to use my Radio Shack SPL meter, (C-weighted, fast response) and got a reading of 84 dB peaks at the listening seat about seven feet from the speakers. Curious what the reading would be closer to the speakers I held the meter a couple inches from the tweeter, midrange and woofers. 

108 dB at the speakers! 

24 dB difference over a distance of seven feet. 

Wasn't expecting that much difference.

tomcarr

Sound pressure radiates spherically so it must cover the surface of a sphere (formula 4PiR2) so it  goes down with R2 (radius squared).  So not at all surprising.

Jerry

Published Sensitivity Ratings, meant to be comparable model to model, are taken 1 meter away from face of speaker.

Formula: 1 watt of signal input/_____ db? sound output measured 1 meter away.

If curious you might adjust for 84/108 as you had it, then measure 1 meter away and see what you get

Answer won't be scientifically publishable, but it will be fun and informative.