I was bored...

[BillESC]

Interesting observation.
Comparing cabinet weight to dB production... Values were taken from each manufacturers web sites and -3dB was deducted from the Peak listing.
Less than 4 dB separates the four cabinets for continious output.
Model - - dB per pound
SP 18a . . 1.12
SbA760. . 1.30
SWA1501 1.40
KX 12. . . 1.76
This is an 18" followed by two 15" followed by a 12"

[Mayhem]

You have way too much time on your hands Bill!

Although - I remember 15 years ago it was a case of bigger is better. Just last week I was amazed at the output from a single dual 6" and ribbon driver line array box.