Originally Posted by Thatsnasty
Ricci I was wondering if you had any updates on the SDX15?
I've still got one and it's probably going to get built when Erich gets the 15" cabinets on DIYsoundgroup.
But hearing that 33%~ of xmax is unusable doesn't inspire me very much.
I'm thinking it might be an issue with the driver as the other threads I found didn't have an issue. Maybe they weren't driving it hard enough?
I have no experience with that driver, but after watching the video i'm almost willing to bet that sound is a coil offset issue. It really sounds like the coil is tapping the t-yoke which is common at higher extrusion if you have a slight bias. Its interesting that is happened in both drivers, but that doesn't rule out two distinct mfr issues that could still be isolated to the two drivers Josh tested... but still could be a more seismic problem that may or may not hit any particular driver.
This was a common issue on the 10" Axis (TC-3000) and in that particular case it had to do with these factors:
Tall gap that had less rocking tolerance with an overhung coil (similar variable with the xbll design) The coil is not overhung, but its almost overhung. The second part of the problem with the proximity of the spider to the cone and coil center of mass in relation to the spider join. In the case of the TC-3000 10" it was just really compact design with a big coil and we ran into collision issues at higher excursion despite perfect gap centering of the coil. The 12 and 15 have a lot more space for better torque control.
This is a much larger driver so i would suspect if this problem, then it is less sever than the 10" TC3k.