If the sensitivity is measured in a room instead of an anechoic chamber, it will be 2-3db higher. Some manufacturers have been known to spec room sensitivity. Also, some specifications say 1 watt and others say 2.83v. If the speaker is 8 ohms, it doesn't matter, they are the same. They are not the same with a 4 ohm speaker. If the spec says 2.83v, that is 2 watts with a 4 ohm speaker, and the 1 watt spec will be 3db lower.
???Why The HUGE Discrepancy in Sensitivity Ratings???
I'm shortlisting speakers & have noticed a HUGE difference in the sensitivity ratings provided by manufacturers & what they actually measure.For example the Martin Logan Motion 35XT is specd at 92db.sens.@1 watt & yet actually measured at 87db!At least 4 different pair of speakers on my list are the same,specd at 90db or better @1 watt yet NONE measured better than 87db so what gives?