go with the alpine type X people say type r is the boomer sub but i dont believe them once u work the type x in it sound hell good especially in a ported box run about 1300watts rms to it ud hit at least 140db but break them in first before u put that much power to it and thats a 10" iam running 800 watts and it sounds crystal clear! U get SPL without losing quality they r good subs. U can get one off of www.onlinecarstereo.com for 275$ pay $40 for shipping =320$ great deal considering they are 500$ or more in stores!
its true.. type r's are a more effecient subwoofer.. with 1300 watts u could run 2 type r's for less money and destroy the type x... type x is more of an sq sub and IS designed to better work in sealed enclosures i think u would notice a drastic improvement in sq going from ported to sealed with x's, lots of people have.. from an spl standpoint type x's are not the way to go.. i do love how they sound though
I've heard many anecdotal reports claim that ONE type-x 10" alpine sub is the sonic equivalent of two lesser quality 12" subs (such as the type-R)!
The advantage of only having one sub is easier install and more trunk space. Plus, you get better SQ to boot. You might actually save money, too, because you'd only have to buy one sub instead of two.