i blew one of their 12's with a small home theater amp that puts out like less than 300w and the RMS is like 800 on the sub. and even before it was blown it sounded like poop
id stick with the plan in your sig (type-x's). Just know that to power 2 x's your gunna need alot more than stock wiring (ex. Big 3 (def), possibly alternator, and possibly new battery depending on ur car)