Same driver, different TS?

[TheBaronGroog]

Have a look at the pic below. There are TS specs for two different drivers, one 12" and one 15", they are both D2 subs and the TS are showing for the same subs with the VCs in series and in parallel. The specs are supplied by the manufacturer and I'd like to know how:

CMS
MMS
MMD

Can change just by wiring the VCs differently? Have the manufacturer botched the measurements or have I got something to learn?

[head_unit]

No, those quantities are set by the physical parts mass and Cms by the suspension.

Q is the ratio those things vs. motor strength kinda sorta. Re is a factor in a Q equation, but without any references at hand to check, I'm feeling the Q shouldn't vary either.

BUT. This in real life, in which you cannot measure parameters exactly. The parameters are a gross approximation model of a complicated physical reality which varies with the weather, the drive signal, and drive voltage/current level.

The variation in the 15" I might expect measuring the same driver on different days. The 12" is somewhat more, but some setups which are more like constant current (500 ohms in series or such) will drive the 4 ohm wiring harder than the 1 ohm, which can also explain different results.

Chris Strahm at LinearX would say Thiele-Smalls are very limited, hence his developing more detailed iterative models. He's right. You simply can't take conventional Thiele-Smalls and worry too much about the decimal places ("Should I size the box for Qtc=0.707 or 0.746?"). It is meaningless.