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
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.
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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. |
@carlsbad2 Correct. Good point! @elliottbnewcombjr Good idea. Will Do! |
- 7 posts total