i agree. at least with RE. never heard the sundowns. but 4 of those won't compare to the 2 RE 15's, in terms of spl. i personally think that 4 8's is loud enough for my ears. 2 15's would be considerably louder, given that the enclosure is big enough. to port 2 15's, you need 6-10 cubes, which alot of vehicles don't have without walling it off. i would take 4 8's in a correctly designed box over 2 15's being choked to death in a tiny enclosure. no contest.4 Sundown E8's or 4 RE RE8's with 800 to 100 watts RMS is what I'd go with. How much space do you have to work with?