Calculate sensitivity of speakers

[jlqrb]

If you have a 3 way system ( tweeter, mid and bass ) where each driver has a different sensitivity how do you calcuate the speakers sensitivity as a whole ?

Thanks for your responses

 

[djoffe]

Assume a system with passive crossovers, e.g. not bi-amped or tri-amped, where you want flat response. The more efficient speakers would have to be padded down to reach the efficiency of the least efficient speaker to get flat response. Thus the overall efficiency is the efficiency of your least efficient driver.

Akitika Preamp and Power Amp Kits

 

[jlqrb]

My mid driver has a 85.5 sensitivity rating. So I can assume my system is 85.5 then. Do I need to get a mic to ensure a flat response ? Also, am I going to need a beefy amp to run speakers with an 85.5 sensitivity ?

 

[AndrewT]

10W gets an 85.5dB speaker up to a maximum output of 95.5dB @ 1m
If that is enough for you then you don't need a monster amplifier.

If you want 105.5dB @ 1m on the peaks and listen at -20dB to -30dB ref maximum, then you would need a 100W amplifier that ticks over @ 100mW to 1W and never gets hotter than quiescent.
But that 100W amplifier limits your average listening level and your peak listening level when you listen at different distances.
Subtract ~10dB for 3m.