Before and after break in

[Buck 5,000+ posts]

This is all true and the specs you have posted seem to change roughly as much as I'd expect to be consistent with woofers I have measured. Also I would say that after 10 minutes of hard play (or whatever test tone ritual you prefer) you shouldn't expect much more variance in the future. The vast majority of TSP change from suspension softening happens very quickly.

As to what manufacturers chose to publish, who knows who is doing what, but as an interesting aside I pulled TS paremeters from an old Clarion 32" woofer that belongs to a friend and got precisely the specs that Clarion published back in the 90s. I've pulled some specs from midranges as well that lined up within a very tight tolerance of published.

I'd be interested in seeing a thread with tested parameters vs posted parameters by the manufacturer.

 

[hispls 5,000+ posts]

I'd be interested in seeing a thread with tested parameters vs posted parameters by the manufacturer.

Not sure how many people buying factory made subs own the measuring equipment (or care to set up a test bench to measure and do the math long-hand). Or for that matter how many people who bought measuring equipment (probably to measure stuff they're building) who will buy off-the-shelf subs.

In any event 15% give or take variance in Fs, Vas, and Qts is to be expected after you stretch out the suspension for a few songs.