What amp do i need for dual 12 inch sub-woofer?

Subwoofer sensitivity for 12 inch and 15 inch?

• Alright, I'm looking into getting an Alpine type r subwoofer. I'm a little shy on cash so I chose this brand. However I'm leaning a little bit more towards spl with this setup. Based off what I know about car audio (which is not too much). Looking at the 12 inch, it has a db rating of 85, the 15 inch has one of 87. Now I'm not sure if I should choose 2 12s, 1 12, or 1 15. I want the lows to be hit hard, so the 15 sounds good for the extra bucks. But if I go with 2 12 inch, am I not going to notice a difference? They say that adding a second sub doubles cone area and adds 3 db. Based from the sensitivity and a little niffty math. Wouldn't I only see an increase of 1 db by adding a second sub? And wouldn't it be the cheapest route to go with 1 12 inch? Like I said, I do not know much, but from what I understand; all options will have slightly different dbs, but will not be a noticeable difference. Is this true? Or do i need to take into account some other variables and specifications of these subwoofers? Thank you for the time and responding. If you have any amp suggestions please let me know.

• Answer:

  Your logic is good. Initially a pair of 12's would have a slight advantage in spl. But on the top end, the 12's can handle more power (1200 vs 750 for the 15), and will convert that into more sound, so ultimately you could see a 2-3db difference in favor of two 12's vs one 15. The one 15 vs one 12, logically, would have about the same margin. Then you have the issue of cost and space. one 12, not a huge box, lowest sub cost, lowest (most likely) amp cost (600w rms). one 15, larger box, higher sub cost, more amp cost (~800w rms), +2-3 db Two 12's - largest box, highest sub cost, highest amp cost (1200w rms) - +4-6db. Just depends on what matters to you.