u/mkecaraudio

Hey guys, iam 16 years old and I ahve a 99 grand marquis, I recently redid the audio system with 4 NVX VSP 6X8 and they are awesome, but they have no bass, I knew this when buying them but I was wondering, what is a good sub setup for like 500-700$ for that crasy bumming bass I was thinking skar audio but idk, wpuld u guys give me recommendations. Thanks