Review on Alphasonik NSW408 Neuron 400 Series: High-Powered 8 Inch Dual 4 Ohm Car Subwoofer with 750W Max Power and Superior Magnet Technology by David Garnic

Modifications for this JBL subwoofer. Be sure to remove the screw on the back of the accessory box that secures the magnet. As mentioned in another review, you need to cut out the recessed part of the subwoofer box (at the back) to accommodate the depth of the new subwoofer. I bought a flat piece of HVAC caulking, 10 screws and a tube of caulk to patch the hole. I rotated the new sub a bit so it could be attached using the new holes. The old ones won't come. I added a 12" jumper cable from the subwoofer to the standard speaker-to-amplifier connector. Instead of using the spacer that came with the subwoofer, I opted for a wider 3/8" window foam insulation, which works better (it's more forgiving). Another reviewer noted that instead of cutting out the back of the case, padding needs to be added to the front of the case. I thought about it but figured patching the hole would be easier than making a properly fitting spacer. Now that I'm done I still think the patch route was easier (but the spacer was a good idea). The phase doesn't seem to matter to the amp. The schematic of the Mach sound system (that I found online somewhere) only recognizes 2 wires going from the amp to the subwoofer, but isn't marked with "+" and "-". Performance: This sub is very highly rated (both with and without a stock amp). Bass is deeper and richer, but the problem is there's not much of it (at least from the driver's seat). The other places seem to be better. There is more bass on the outside of the car, but from my point of view this is a minus as I don't take pleasure in hitting my fellow passengers. Maybe an aftermarket amp will improve the bass, but that's enough for now.