Hi all,
Can anyone tell me what is the effect of Bl and Mms on loudspeaker sensitivity and which components can be changed/modified to alter Bl and Mms?
Higher Bl usually means more sensitivity, well more the B than the l. B is the magnetic strength of the permanent magnet, and l is the length of the voice coil. The configuration and mass of the coil will effect the sensitivity and efficiency; lots of coil means that the moving assembly will weight more, and when a big chunk of the coil lays outside of the gap, that means a lot of electrical current is being wasted so you can also have lower sensitivity that way.
Mms is how much mass the moving assembly has and it also accounts for the air mass that the cone has to push. Obviously the more mass that has to be moved, the lower the sensitivity. Heavy subwoofer cones will have genarally low sensitivity but they will have a lower resonant frequency where they will be a bit more efficient.
There is a lot more that can be said about both those parameters and the components which affect them, but that is the very basics.
