Ok I have Polk speakers but need a better subwoofer for my HT! I want to buy a sub that is going to go down to 20hz in a large ported box. I was hoping to stay at about 6ft3 after all displacements. What would be a good sub for this? I have a 1000 watt Dayton amp right now for my 12" sub. I was hoping to spend $300 for the sub or less. Would this sub work well or no? Amazon.com: Brand NEW Re Audio Sx18d4 18" 1,000 Watt Rms Rated (2000w Peak) Dual Voice Coil 4 Ohm Car Subwoofer with Triple Stacked Magnets and a Cast Aluminum Basket **Hand Built in the Usa**: Car Electronics
