Anyone ever measured a Vifa C13WG-19-08's T/S parameters?

[IG81]

Hello,

I bought a pair of the aforementionned drivers at an auction type thing for a fairly low price.

The problem is that the T/S parameters I measured are pretty much out of whack! Most disturbing is that Fs is at ~84Hz instead of 55Hz... Qms/Qes are 1.03/0.77 instead of 1.4/0.55, but since they also depend on Fs, I'm not looking into that first.

I'm certain my measuring method is not at fault here as I used it many times and successfuly so.

I understand Q parameters are often a bit off from datasheets, but Fs??? And by that much???

If you have ever measured this driver, I would like to know if you had it do similar things.

Thanks!

IG