Confused about power usage O.o

[Mugen 10+ year member]

Alright, so let's talk hypothetically here.

I have 2 subs, 4 ohms each. I have one mono amp, that does 450w @ 4ohm, 900w @ 2ohm, and 1200w @ 1ohm. Which number do I divide by two to get the power each of my subs will receive? IIRC, someone said it'd be 900w/2 = 450w on each sub. But why would the amp run at two ohms, while the subs would have 8ohms resistance total?

LINKS:

Assassin 8"s

BXi 1206D

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[ultimate157 5,000+ posts]

Alright, so let's talk hypothetically here.
I have 2 subs, 4 ohms each. I have one mono amp, that does 450w @ 4ohm, 900w @ 2ohm, and 1200w @ 1ohm. Which number do I divide by two to get the power each of my subs will receive? IIRC, someone said it'd be 900w/2 = 450w on each sub. But why would the amp run at two ohms, while the subs would have 8ohms resistance total?

LINKS:

Assassin 8"s

BXi 1206D

It's only 8 ohms resistance if you wired them like this:

It's 2 ohms if you wired them like this:

So yes, it's 900w / 2 = 450w RMS to each sub. I have heard hifonics are overrated, so you're probably putting 375ish to each sub. So that's perfect for those subs

 

[Mugen 10+ year member]

Ah, thanks. I just wanted to make sure before dropping $240 on an amp.

 

[Mugen 10+ year member]

I actually have another question, I ordered a 4-gauge kit as well, can I just leave my 8 guage wire that's powering my mids and run the 4gauge with that? So I'd just have them both connected to my battery, and as someone told me before, hook the grounds up to the same spot (I don't know why, but that's what I was told).

 

[audioholic 5,000+ posts]

I actually have another question, I ordered a 4-gauge kit as well, can I just leave my 8 guage wire that's powering my mids and run the 4gauge with that? So I'd just have them both connected to my battery, and as someone told me before, hook the grounds up to the same spot (I don't know why, but that's what I was told).

Yes, that's fine.