SVS PC12-PLUS Disappointment

I've had my sub for a couple weeks now, and it has been impressive until tonight.
I watched LOOPER at a modest volume (-25db) and at several points the sub rattled...not good...my focus went to the sub immediately...

I'm wondering if moving to an SB13-Ultra would be worth the additional $400?

It wasn't a port noise type sound, it was more like a vibration or rattle, it sounded like it came from the sub.
I'm still within the 45 day in-home trial period, and am wondering if going with the SB13-Ultra would be worth the extra $400

Either way I need to send the Plus back, question is exchange it for another model or repair it?

Good idea, thanks for that...I'll give it a try...

I downloaded the test tones, burned to a CD.

The 16Hz and 20Hz tones produced the rattle.
It turns out the rattle is the wall directly behind the sub. A little pressure on the wall stopped the rattle.

A couple well placed drywall screws seems to have corrected the issue....Now I get to Spackle and paint....

Thank you LastButNotLeast, that was a very good suggestion....

It does work well, I thought if I had to send it back, would it be worth the upgrade?
Since it works, no reason to fix it....

Indeed, the sub is doing what it is supposed to....
It was just coincidence that the rattle in the wall was directly behind the sub from my LP.

I was seriously thinking I had a problem with the sub, I'm glad I didn't.
Over the years I've bought so many things that didn't live up to the expectations, so far, this sub has exceeded them....KNOCK ON WOOD....

Or perhaps some Aspirin....LOL...