Quoted from Markharris2000:
If using an external sub, you took a different approach and probably getting all the low-end you can handle! That said, I like the self-contained approach, which leaves the machine identical to the way it shipped from the manufacturer and can be sold without needing any explanations about extra boxes.
Looking at the installed picture you can see I did not add any type of amplifier and just moved the two wire connector from their OEM speaker to my CXX8 (some simple testing showed me that the built-in cabinet speaker amplifier has plenty of power... it was just missing the way to get the power out effectively). In a previous note I showed the Kicker DSC40's I installed in the backbox (uses the same 4-inch mounting), and coupled with the CXX8, I wanted to show a $75 all-in upgrade for the top and bottom that makes a big difference.
So I am getting ready to order those kicker cabinet speakers that are recommended, I noticed that the stock ones are 8 ohm speakers. I don’t have a ton of speaker knowledge, so I am wondering why we wouldn’t have to replace the factory speakers with 8ohm instead of 4?