OHM options

[dkahns51]

What are my options for the final OHM with 3 D4 subs on a MONO amplifier?

[Cashdollar2009]

Each sub parallel down to 2, then all three paralleled down to 0.67 ohms.

Each sub parallel down to 2, then all three series up to 6 ohms.

Each sub series up to 4, then all three parallel down to 2.67 ohms.

[Cashdollar2009]

I wouldn't reccomend 0.67 ohms for a daily application. With your configuration, 2.67 would be the lowest impedance possible that wouldn't void any warranty or risk general equipment failure.

[Cashdollar2009]

I don't know how to edit on mobile, so I'll make one more post.

Although three 12"s has more cone area, you will see more than twice the power on only two subwoofers because you would be able to obtain a final load of 1-ohm. Depending on the subwoofers, you may be better selling the third and investing in wire to upgrade your big three or look into a secondary battery to maintain a higher operating voltage as you would be wired down to 1-ohm.

So you're really looking at theoretically 33% more cone area vs. 150% more power. I vote power. Just my $0.02.

[dkahns51]

I already got the big 3 done with o gauge, upgraded battery up front and 2nd battery in back as well as a 250 amp alternator. With a Rockford t2500 bd-cp would I be able to go with the .67 ohm or should I stay at 3.67?

[Cashdollar2009]

Those constant power series amplifiers are nice. I'm planning to run a pair here soon on some DC XL's.

As far as your options, if you insist on running all three, I'd definitely say to stick with the 2.67-ohm load. Luckily in your case you have the "constant power" series amplifier, therefore you'll still probably see a ballpark rated 2400-2700wrms at that load. If it were basically any other monoblock, you'd see your power cut substantially going from 1-ohm to 2.67-ohms.

What kind of subwoofers are you looking to run?

[Toby Ratcliffe]

That amp is 1 ohm stable. You might be able to get away with .67 ohms, but I would base that decision based on the power requirements of the subs as well. You are going to get about 1500 watts at 2.67 ohms, and somewhere around 2500 watts at .67. If your subs are looking for 500 watts RMS, stay safe with 2.67. If they can do 1000 Watts RMS, then I would try .67.

NVM, just saw that it was the CP version.

Edited April 21, 2012 by Toby Ratcliffe

[dkahns51]

I was thinking of adding a 3rd SXX 15" d4 Re audio sub... but being that i can only go 42" wide and 29" tall i dont think i can fit 3 now. Im going to look into it more cus im going out of town and i will have alot of spare time on my hands :/

[BEEMDUB]

use this as a good reference also

[bkolfo4]

Each sub series up to 4, then all three parallel down to 2.67 ohms.

This is wrong.

(3) 4 ohm drivers in parallel is 1.33 ohms

Edit - but now I see they are dual 4, so that would be:

"Each sub series up to 8, then all three parallel down to 2.67 ohms"

Edited April 22, 2012 by bkolfo4