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Mat Nieuwenhoven wrote:




Technically, you are correct. The 1998 book "Testing loudspeakers"
from D'Appolito gives the formula in chapter 2.8.3.

** Ya don't say.

I like to provide references if possible.


** A tedious pretension to non existent expertise - I'd say.




For practical use with given amp, a speaker with a higher SPL at
2.83V will sound louder than one with a lower SPL, even though the
latter one might be more efficient when looking at SPL/Watt.


** Sorry, that makes no sense at all.


Say if I were to replace the small speakers of my home stereo by ones
that can provide a decent SPL at much lower frequencies, and I have
the choice of two, one with an SPL of 80 dB and the other with 85 dB
(both measured with 2.83 V), then the one with 85 dB will be
noticably louder with the same volume settings. That is obvious.
Now if these speakers are 6 ohm, and there is a 12 ohm version also,
then driven with the same amp the 12 ohm version will be less loud
(its SPL at 2.83 V). Yet if one measures both speaker units with
regards to efficiency (sound per watt), the 12 ohm one could be more
efficient.


** Complete ********.

Try actually reading my earlier post directed to YOU and see that the spec is for an *applied watt*" so the rms noise voltage used *DEPENDS* on the speaker's nominal impedance.

2.83V for 8 ohms, 4V for 16 ohms and 3.46 for 12 ohms.

BTW Learn not to over snip.




...... Phil