[Paul McNeil]

When driven too hard, they just hit the magnets and slap. This will lead you to turn them down, so there's no damage to the woofer. If you did put an absurd amount of current through them they'd no doubt suffer thermal damage, since they aren't fused. But they have a large surface area so ordinarily the midrange and tweeter fuses would blow long before the woofers were damaged.

Delamination occurs in older models but not in current or recent ones, since they changed the adhesive.

Thanks, that's a relief, Josh, it was slapping...!

[I.Greyhound Fan]

Thanks, that's a relief, Josh, it was slapping...!

Yes, the bass slap is different than the bass rattle.

[Davey]

Another factor that makes planars particularly difficult to match a sub with is that the planar elements tend to start and STOP very quickly/precisely, which makes it very difficult for a cone driver to keep up.  This is why so many subs sound slow and bloated when compared to the main speaker. 

What the GR Research subs do is add servo control the the system so that the drivers not only start moving quickly, but also STOP moving very quickly.  This gives them a MUCH better match to the blazing-fast sound of the planar elements.

I think you'll find that planar motor structures (like Magnepan's) have quite a bit of energy storage in them.  To say that they start and stop very quickly/precisely is not correct.  Relatively speaking, many other transducers have superior capability, in this aspect.

I like the concept of servo-control in dipole woofers and the system employed by Brian seems to be well done.  I do always find it a bit funny though since many audiophiles seem to be loath to the usage of negative feedback in their audio components.  Yet another irony in the vast world of the audio industry.

Dave.