pioneer subwoofer

I just got 2 TS-W309S4 subs and I pushed gently on the woofers, and they sounded like a grinding sound from one of them when I pushed on the woofer. I checked for damage, but nothing major. I got these subs brand new. Please help

Hey, I just bought 2 Pioneer Champion TS-W309S4 12" 2800 Watt Peak / 800 Watt RMS 4 Ohm Car Stereo Subwoofers in this Amazon deal: Amazon.com : Package: (2) Pioneer Champion TS-W309S4 12" 2800 Watt Peak / 800 Watt RMS 4 Ohm Car Stereo Subwoofers + Dual 12" MDF Vented Subwoofer Enclosure + Dual...