2-15s or 2-18s

[Welder84]

I currently have 2 15s, I'm not trying to get into all specifics, but more of a general question.... I'm trying to get noticeably louder in my system... With sufficient power supply, amp power, custom box, etc, is there a noticeable difference between the 2-15s vs 2-18s...? We've all went from bigger to smaller and more subs trying different routes for deeper and or more punch, but im trying not to spend another$3000 for differences not really noticeable...

Also... Anybody running a single dd9521 that feels they are really impressed and worth the money?

[slowfkncar]

Direct swapping the same model woofer for a bigger size off the same power "generally" gives more output if done right. 

[d-nice88]

I went from 15's to 18's and i love my 18s wayy louder imo. Just make sure you have the proper air space for the 18s they like a HUGE box