I would ad a big positive shout out to JL Audio service.
The amplifier in one of my F113V2 subs died (out of warranty, purchased over six years ago) and my local dealer indicated that JL does all the service. So I contacted them via their website and found that, for out-of-warranty service, they offer a fixed repair price that includes installing the updates they offer in current models. Since the subs weigh so much they need to be shipped by truck, JL provided me excellent instructions on how to remove and later re-install the backplane amplifier, so the package could go via UPS.
I give JL an A+++++