hi Guys, a lot of questions! i'll try to answer as many as possible!
first off, yes i am involved with Tymphany, the STW is actually my concept and i was steering the design.
yes, we have had the driver on klippel, probably a few hundred time over the development, we're not against publishing the data, but we have had some issues with the klippel system measuring at these power and excursion levels. we're working through those with Klippel themselves and aim to publish data once the measurement issues are resolved.
I'd be highly skeptical of anyone developing transducers who don't have frequent access to a klippel test rig.
also bear in mind it's a hugely flexible piece of test equipment, you can use it to give 2 seemingly very different sets of results depending on how you set it up,
i can confirm that we've had 91.x mm P-P repeatedly from the STW using the Klippel system.
Xmax, the most abused spec after power!
there are many ways to describe Xmax, some make sense, some do not, but they vary a lot!
none of them really tell you how far the driver can move in use, - there are too many variables.
the most honest way is to give Gap length, coil length, VC overhang, or from 2 of these you can calc the other,
this however doesn't give a headline figure,
remember that for a subwoofer, high Xmax is not always relevant, as the driver will see significant excursion in average use.
more important is the width of the BL curve at moderate excursion. the shape of BL curve, and how this balances with the compliance/inductance non-linearity,
we compared the current design to one with the same VC length and Xmax (VC overhang) of 25, and the 25mm xmax driver performed worse, in any real world conditions .
sensitivity for subwoofers - the most mis-understood parameter!
published sensitivty can be defined a variety of ways, some honest and some very much not!
we have found in real world testing that other manufacturers drivers show up to 3dB higher on the spec sheet than in real life,
we publish both 1w/1m and also 2.83v/1m which is what most companies use,
2.83v is only accurate for an 8 ohm driver... a real 8ohm, not a 5 ohm DCR woofer described as 8ohm!
for subwoofers all these measurements are pointless....
the spec sensitivty quoted everywhere is a mid-band sensitivity figure,
and nobodyy uses a subwoofer at these frequencies,
even a sensitivity at 50hz or 100hz would be fairly pointless on it's own, as they are taken in an 1/2 space environment, (no box)
to give an example, take any pro PA woofer, from any manufacturer, even a TYMPHANY one like NCP1540, this has very high published sensitivity which is fine as it's designed to be used at low and mid frequencies,
now put it in a small box, and measure the sensitivity at 40Hz, as you need for subwoofer use... somewhere along the way a boat-load of sensitivty got lost !
you can only compare sensitivity of subwoofers in-box and at the frequencies that you'll be using,
the STW has great sensitivity in a small box at true subwoofer frequencies, where it will be used.
nearly all of the simulation tools on the market either just use the TS parameters and assume these apply at all excursions, or they apply some rule of thumb assumptions,
this is ok for most regular mid-woofers, but falls over with the unusual designs like very small or very large voice coils, many subwoofers etc etc.
if you really want to konw how far the driver moves in-box, build a box and try it!
the simulations are good to get an aproximate box size/tuning, but then you need to prototype, this applies to any drivers made anywhere,
also measure your own TS parameters, if you have a consistent reliable way to do so,
I see a lot of lower cost drivers with totally bogus specs! or where the batch to batch variation is so bad that the spec sheet parameters are pointless.
very few manufacturers give tolerance on their specs, this applies to a lot of high end companies too!
surround height, i don't have the measurements to hand, but go measure a driver, the surround is not tight, even at +/-45mm.
my earlier comments about panel size:
the panels of an 8 cu ft enclosure has 29x the area (Sd) compared to the driver,
this means that even a tiny displacement in the panels can produce SPL that is significant and undesired,
reducing the cabinet to 2 cu ft reduces that ratio to 11, so basically a factor of 3 reduction in panel area, that combined with the inherent stiffness improvement in the smaller cabinet, makes for a quite audible difference,