If by VOX you mean vocals, then it would be that your crossover isn't set on either your amp OR your 9853. The LPF on the deck should be set to either 80 or 120Hz (whichever you prefer) with at slope of at least 6dB. I'm not sure what the 9853 has for crossover slope adjustments, but my 9855 has either 6, 12, 18, or 24dB settings. Try that and see what happens. Also, make sure your crossover on the amp is either set to LP if you're going to use it's crossover, or to OFF or FULL if you're going to use the deck's, but it's redundant to use both and can cause you even more problems. Also, make sure that your RCAs are in fact connected to your sub-out on the deck and not the rear-out, since the rear-out is designed to play high passed frequencies.
Good luck, and welcome to the forums.. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif