Hi Atmasphere, I think we are on the same page here. I have built 1 amp and modded a few, but I'm a simple minded speaker guy. I try to speak in the simplest terms possible on these forums, because it took my feeble mind a long time to get where I am, which is mediocre.
Sensitivity is a measurement of power, so 1 watt input measured @ 1 meter gives an spl or sensitivity rating... so yes 2.83 volts does measure 1 watt @ 8ohms and gives you a sensitivity rating for an 8 ohm speaker, but to measure a 4ohm speakers sensitivity, we still put in 1 watt, yes lower voltage, but 1 watt of power to get the output or sensitivity rating.
Where as efficiency ratings are measured strictly in voltage. We have found many variations when measuring a speakers efficiency at different frequencies that do not necessarily coinside directly with its sensitivity rating. Crossover components, cabinet designs and direct driver designs measure slightly different at different frequencies, thus being more efficient at a given frequency, yet overall might measure the same as a different speaker in sensitivity. Again, I believe that we are on the same page and I hope that I am only clarifying your statement. Any way you look at it, sensitivity vs efficiency is similar and can be confusing. Overall, just get enough power and if you are using tubes, try to find your speakers impedence phase angles and you will come out successful. Tim
Sensitivity is a measurement of power, so 1 watt input measured @ 1 meter gives an spl or sensitivity rating... so yes 2.83 volts does measure 1 watt @ 8ohms and gives you a sensitivity rating for an 8 ohm speaker, but to measure a 4ohm speakers sensitivity, we still put in 1 watt, yes lower voltage, but 1 watt of power to get the output or sensitivity rating.
Where as efficiency ratings are measured strictly in voltage. We have found many variations when measuring a speakers efficiency at different frequencies that do not necessarily coinside directly with its sensitivity rating. Crossover components, cabinet designs and direct driver designs measure slightly different at different frequencies, thus being more efficient at a given frequency, yet overall might measure the same as a different speaker in sensitivity. Again, I believe that we are on the same page and I hope that I am only clarifying your statement. Any way you look at it, sensitivity vs efficiency is similar and can be confusing. Overall, just get enough power and if you are using tubes, try to find your speakers impedence phase angles and you will come out successful. Tim