As Erin Hardison has shown in some of his speaker reviews, the 70% Bl Xmax can be crap, but isn't necessarily crap. The Scanspeak Illuminators only have 6 mm one-way Xmax by the (gap height - coil length)/2 method, their stated 9 mm Xmax is likely a 70% Bl measurement.Interesting that's good to know... Sometimes you get lucky and the speaker klippels at slightly higher xmax than the voice coil overhang... not usually though... usually its less. The thing that worries me is I see a post on facebook from Stereo Integrity saying the new TM65iv prototype is supposed to have 11-12mm of xmax @ 70%bl.... Well what about the suspension and inductance xmax measurements? This is not a subwoofer I want to know what the true klippel xmax is under 10% distoriton... not just the BL measurment... Anyways I have serious reservations that the new tm65iv has as much xmax as the scan illuminator...