Hi Wayne. On cone break up. The comment pertains to the over 50 year old Altec 416a which I use with the 811b in the A-7 set up. It seems to work well up to about 800-1200 but not at 1600hz. I have 4x 4648a boxes with 2226 woofers. One pair is used with the Pi crossover at 1600 hz ( pseudo Butterworth) to the JBL 2426-2370. I hear no break up or any problem with this woofer in your design. I love it. The old Altec system is used with triodes and vinyl. Its warm and wonderful but maybe a bit fat. Goes well with Merlot, Cabs and Zinfandel. I use your system with s.s. amps (Crown and Apt) for everything else. tdc