I have a blown driver and I'm not sure what to do

My thoughts should first be targeted towards amplification.

Please check DC(using conventional DC voltmeter or DMM) when system at idle on the speaker terminals or buy woofers in bulk for your 7.1 system 2 per each speaker just in case. After checking DC at idle, I would check with 1khz/.5Vrms input signal to check DC on the output. That requires either signal generator or Serato LP or any record/CD with test signals.

Meanwhile, don't keep your system on at idle and turn off

When I hear Denon AVRXXX, I freak out. They're unpredictable, unmanageable, and unserviceable and may reveal LOTS of intermittent problems.

They throw an array of intermittent problems within the time of usage and do not match specified parameters. As previous posters noted, use this AVR only at moderate to low volume levels and do not try to reach IMAX SPL. Also make sure that your speakers do NOT go bellow 6Ohms (which isn't probably the case with your paradigms, but who knows...) or your AVR will be history shortly after blown woofers. The output amp modules are not designed to drive heavy speakers even if specified parameters are showing contrary.

Well,

Are you willing to go separates or just replace receiver?

I like Carver/Sunfire amplification and would aim for either receiver similar to Cinema Grand or Ultimate Receiver or TGA/TGP combination.

Sell your Denon till it has warranty and value, because they turn to $50 scrap junk very fast. TGA/TGP will always hold value with minimal depreciation.

Meaning of separates is broad, but the core idea is to use separate processor and separate multichamp. You can also separate music from movies using either dedicated amp or dedicated amp/preamp for mains with theater bypass.

I moved, and re-did the speaker configuration using Audessy in my new home. The crossover was set to 80 mhz, but the speaker size was set to small. I can’t see much more detail than that, but I wonder if that’s why it would under-drive the speaker.

Technically, you’re not under-driving or over-driving speaker, but practically, read my prior note about Dennon AVR units. As a service man and techie I told that these units are unpredictable, overly sophisticated and absolutely unmanageable and unserviceable (anyone tries to ask me fix their Denon AVR, I simply send them away to whoever has another technical opinion about them). Your unit most-likely fails at some point and destroys your precious speakers. The point is you never will know the exact reason when dealing with it. If you try to make warranty claim and succeed, it will be a very good time to sell it right after you’ve been granted either overhaul or complete replacement of unit.

I stick to Sunfire products as they’ve presented to me maximum neutrality, precision and the most objective and truthful reproduction of instrument and voices with sufficient dynamic headroom. There are people that love Anthem products, but I find Sunfire giving more for the value.