It seems to me that if you have two woofers that have identical motor assemblies and are otherwise mechanically identical except for the area of their cones and their cones have the same mass (and thus the cone and coil assemblies will have the same mass), it seems to me that the one with the larger area will me more efficient.

Reasoning follows:

I am extrapolating from newtonian mechanics in that the maximum energy is transfered in two colliding bodies (such as billiard balls, for example) when the colliding bodies have the same mass.

In regards to dynamic woofers, the woofer moving system usually (cone and coil) has much more mass than the (nearby located) air it is trying to move. A larger cone is in contact with more air, so all else being equal, the mass of the (nearby located) air is more nearly equal to the mass of the woofer moving system of the woofer and so will transfere more energy from the moving cone to the air, thus the efficiency of the larger coned woofer will be higher.

Also, to reproduce the same SPL, the larger coned woofer will exercise (tax) the drivers mechanical suspension less, and beings many of the suspension compnents have elastomeric mechanical properties, the larger coned woofer will produce less distortion.

In either case, for subwoofer use, the upper limit of the frequencies that the woofer is being asked to reproduced is much, much less than what the woofer can reproduce without significant directionality and is established by the crossover. If this is not the case, then we are not talking subwoofer application or else we are talking about a driver of several feet in diameter.

So, size does matter.

Unless there are space constraints that rule out a big subwoofer (or WAF problems), bigger is better.

Paul

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the 1derful1