with $60 worth of mods it is like a good $500-600 sub (still a tad shy of the performance of an M&K and that may be fixable with a high quality replacement woofer). How do you transform any regular sub into a superior one? Go to PartExpress.com, order (8) 10x10" sound deadening sheets (part# 268-010) to cover all of the open wood panels, order 3M Spray 74 Super Foam Fast Adhesive (part# 340-270) to be able to attach (2) rolls of acoustic foam 1-1/2" 24x18" squares [scissors easily cut the pieces in 8 equidistant rectangles] (part#260-316B) to the sides, top, and bottom of the previously installed deadening panels. Next turn the box over, and install the Dayton Audio Black Chrome Speaker spikes (Part# 240-715) you ordered to de-couple the sub from your carpet, hardwood, or vinyl floor. The hole for the speaker spikes are basically prefabed for your where Audiosource notched in the spots to place the screws to hold those cheesy rubber feet. The spike set includes floor protectors for those with/out carpet floors in your listening area. Finally, return that cheesy piece of insulation that was placed inside the sub back into the enclosure, but take scissors cut it in half and partially block the rear of the port (these cheap style ports weren't designed to avoid port noise). Now, reseal the speaker or a new 4 ohm driver of your choice back into the enclosure using speaker sealing caulk (part 269-300) [tacky, rubbery type compound that is moldable and has no perceptible odor] to absolutely seal off any air leaks. Set the speaker upright in your desired listening location, balance the box to insure absolute sturdiness, and prepare to be blown away. The