It is known to most here that VC wire tend to heat with power, and the change of resistance that heat provoke has direct consequences on the response of the driver, shifting its BR alignment and reducing its sensitivity, ultimately limiting the maximum possible SPL.

This is the so-called "power compression" effect. JBL and other transducers manufacturers have been using vented motors and heavy metal parts to dissipate that heat and reduce the long term effect of it, improving long term maximum SPL.

But this phenomenon also has a less known immediate "compression" effect on peaks on which external dissipation techniques have no effect, because it does not have enough time to take place.
One way of dealing with this phenomenon is to use current drive amplifiers, but that is another subject.

Earl Geddes calls this effect "thermal modulation", and this phenomenon has also been brought to consideration recently by Charles Sprinkle here, with what he calls dynamic compression.

This immediate effect has to be dealt with within the VC itself, by either increasing the mass of the VC (the bigger the VC the less it will heat), or by using special alloys whose resistance stays more stable with heat.

That is what Doug Button patented for JBL in 1994, and called TCR:
http://www.jblpro.com/www/jbl-story/...oice-coil-wire

The M2 brochure explicitly states that this material is used in the 2216nd transducer, but it is not made clear in the EDS, and to my limited knowledge no other transducer has been reported to be using that type of wire before, not even the 1500AL series.

Is that the case? Is the 2216nd the only woofer to use TCR wires?