idk why people are saying their over powered, from what i keep seeing here on this forum, those woofers can take 800-1000+w or so, and im sure their not seeing even close to that after voltage loss, on top of rise, shit maybe 600 per if he's lucky which if their seeing 600w they should be just fine in that box, and he shouldn't be clipping (on music, which is normally -10db) if he set his gains with the DD-1 on a -5db track
unless he is "unlucky" and is seeing 0 rise and getting 2k+ out of the amp
edit:
i did a build in my friends civic who had 2 lvl 3 12s, the "m1"s on a crescendo bc2000d on a 3.44 cube box and didnt have any issue like this, and that was back before the DD-1 was even thought of, competed 90% of a season with it so power/box really shouldn't play an issue here....