Amp & sub matching

What will sound louder:

2 RFP4415    RF 15in SVC 200RMS/400MAX

or

2 P312D4      RF 12in DVC 500RMS/1000MAX  wired in series/parallel for a 4ohm bridged load

with a

RF P8002

200 W x 2 @ 4 Ohms RMS
400 W x 2 @ 2 Ohms RMS
800 W x 1 @ 4 Ohms Bridged RMS

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Poly Dollies

the 12" subs will be louder because you can wire them up so that they present a single 4-ohm load to your amp, giving you a total of 800 watts RMS (400 per sub).  with the 15" subs, you'd have to wire them up in 4-ohm stereo, which would only give you 200 watts per sub.

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Ethan
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"Patience, persistence, and perspiration make an unbeatable combination for success"
Donate to the12volt.com

Eh. What esmith69 says is true. However, in the real world, the difference will be small in terms of SPL. The 12" is 87db efficient. The 15" is 88db efficient. A doubling of power to the 12"s will only put them 2db max SPL past the 15"s. This is tiny.

I'd focus more on matching the subs to the enclosure design and desired frequency response curve than worrying about pulling an extra 2db out of your system. Unless you compete, who cares about 2db?

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New Project: 2003 Pathfinder

The 2 12p3 will slam in a ported enclosure, but the 400 per sub is not going to move these subs like they need to be moved.If you can afford a better amp I would go with an amp that put out at least 600 per sub. I have 1 p3 and im feeding it with 1000 watts and it drives so hard that it hurts, when the bass hits its like somone hitting you in the back. or  I would just by one pl3 12d2 this is already in a ported enclosure run it in series @ 4 ohm and use the 800 to drive the one sub and I think you will be happy with that

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wheelerdr wrote:

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The 2 12p3 will slam in a ported enclosure, but the 400 per sub is not going to move these subs like they need to be moved.If you can afford a better amp I would go with an amp that put out at least 600 per sub. I have 1 p3 and im feeding it with 1000 watts and it drives so hard that it hurts, when the bass hits its like somone hitting you in the back. or  I would just by one pl3 12d2 this is already in a ported enclosure run it in series @ 4 ohm and use the 800 to drive the one sub and I think you will be happy with that

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What?  Unless he's competing I don't see any point in moving from 400 per sub to 600 per sub.  You do realize that an extra 200w per sub here won't even yield a MAX increase of 2db, right?

Actually, his 400 per sub to 2 subs will "hit" just as hard as your single sub setup with 1000 watts.  Sorry, his lowly 400w per sub setup will actually be a big bad 2db louder than yours.

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New Project: 2003 Pathfinder

if he is not competing i just dont see why he should spend more money on 2 if he can have nice bass with one and save some money, and drive the sub a little better,I know this sub says 500rms but it is very under rated, with 400 watts you will get about 1" excursion with the 1000 I get max excursion and the sub slams, just trying to save him some money

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2 subs at 400 each might be cheaper than going w/ the bigger power number on the amp - and louder!

Since when was pushing a sub to max excursion a good thing when not competing?

Edit: Hey, I 1/2 agree w/ you. I prefer one sub. I'm just trying to play the devil's advocate here because I disagree with your reasoning. ;-)

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New Project: 2003 Pathfinder

So compared to the pair of sony XS-L121P5 12" 350RMS/1200Max, whichever combination I get  (a pair of 12 or a single 15)  I should get improved db and better response from my system.  I wanted to get them in a sealed inclosure because of space constraints but I guess I could fit a 2 x 1.3 cu. ft. box for a ported inclosure for the 12's.  How would this compare to the sigle RFP4415  15"  (Ignoring money for a little bit)?

I should practice making ported inclosures.  It might be fun.  I can go to lower frequencies with the ports right.  That way I can put my earplugs on and get a really inefficient, heat producing massage to the beat of a song.

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Poly Dollies

I suggest you learn WinISDpro or similar enclosure / driver modeling software so you can see for yourself. :-)

There is a slight learning curve, but the ability to conduct analysis and make your own buying decisions is worth it, imo.

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New Project: 2003 Pathfinder