LE, not MMS determines woofer "speed"!

I don't know much but for 12" tapped horns down to 40hz mms has to be in excess of 80g, preferably 100g and a bl factor in excess of 18 (big magnet).  But for the power handling the voice coil must be larger and thicker glass fibre/paper for strenth so also resulting in a bigger mass.  Sims do not work with low mass units despite 25bl or 10mm xmax

Going back to the OP, (I have not read the paper) it makes assumptions that transient response and speed are not linked which seems odd too.

Having re-read the article I am now somewhat confused about a number of points the author makes:

Firstly, Im not convinced that discrediting values that form a constant directly related to the experiment is such a clever idea unless attempting to force the captured data into an outcome you had previously decided on.

Secondly, its a goddamn loud speaker. I would wager that by the laws of statistics 100% of the loudspeakers on the planet are for playing music.
With that in mind, why does it seem like the author is only interested in movement from a driver at rest across a single impulse (not sure I hear much of that going on in music) whilst addressing and completely disregarding the ability for the driver to reproduce a transient whilst already in motion (like kick drum and snare for example).


Or am I missing something here?

Most of the "it's like a motor, higher force is better" similarities are just plain wrong; as far as bandwidth and speed and transient response are concerned, the T-S parameters tell you how the driver behaves and what the frequency response in the cabinet will be. When people say a driver/cabinet is "fast" what they often really mean is that it's bass-light, ones which are flat down to lower frequencies are often said to be "slow" when actually they're more accurate. A driver with a big heavy cone/coil needs a strong motor force (M-force is the extreme example of this), applying this to a lighter driver leads to low Q and bass rolloff unless the cabinet is designed to work with this -- which usually means a big FLH.

Coil inductance just acts as a bandwidth limiting factor (lowpass filter) if it's linear, and for most PA bass drivers the cutoff from this is well above the crossover frequency -- not always true for drivers aimed at home theatres which can have huge heavy high-inductance coils. But the bigger problem is when the inductance varies a lot with cone displacement, which causes distortion because the filter cutoff changes as the cone moves. So keeping the inductance low and more constant by adding demodulation rings does make for a cleaner sound, which is why the more expensive higher-quality bass drivers often do this.