Is The Overall Weight Of A Speaker Important?

Only in that the heavy speaker is better at geting the acoustical energy created by the drivers transferred into sounds waves instead of vibrating the cabinet or in some cases actually moving the speaker back and forth.

One of the cheapest tweeks that I currently employ is setting a very heavy weight, about 30 lbs, on top of my very compact subwoofer. It is a Velodyne that has an extremely long throw driver inside a cube barely larger than the driver itself. It turns out that the subwoofer was not heavy enough to keep it from moving back and forth when at medium or high output.

It's not like it was walking across the floor but the bass tightened up and the transient attack is noticebly better with the sub weighted down.

I agree that it has a lot, or everything to do with controlling cabinet resonances. Imagine what a Magico aluminum sub would weigh. I don't think they have any plans of making one.

I'd guess its more a matter of designing towards enclosure stiffness which may naturally add weight.

There are other designs that rely on the cabinets flexibility to produce a desired goal.

And the ANSWER is???

I think so. I shy away from speakers weighing under 60 lbs each.