Install the woofers 180 deg out from what they were when you got them (rotate them so top is bottom and bottom is top). That should help with spider sag.
The AR9 is a super speaker, but you will need serious power to drive them to satisfactory levels. If you try to drive them with under-powered amps, you will tend to drive the amp into clipping, trying to get decent volume out, which will burn out your tweeters and midrange drivers...clipping hits a limit on base power, which is where most of the the loudness lives (see Fletcher Munson Curve). From there you can still increase the power in the midrange and tweeter frequencies, shifting the power distribution upward, as the speaker sees it, sending too much power to the midranges and tweeters, trying to get the volume up. This can result in frying those drivers.
Enjoy,
Rich P