2 subs

[white04alero]

ok, right now im running one amp and one sub.. amp = Scosche 550 watt amp from walmart i bought 2 yrs ago.. been holding up alright i guess. well, no, it blows, and my sub is a mtx thunder 8000... pretty good if it had the right amp, but again my amp blows.

the q is what would have to be done to have 2 subs ran off of 1 amp. im planning on getting a new mtx amp and new mtx subs.. 2 of em.. and planning on spending some money.. but i want it reasonable. anyways.. if i got 2 subs running 400w rms at 2 ohms.. would i have to get an amp that was capable of running 400w rms at 2 ohms or 800w rms at 2 ohms?
or... will an amp running 400w rms at 4 ohms run 800w rms at 2?

thanks.

[Ryan from Ohio]

Ok, the basics.

Your subs dont run at RMS. They accept that value on a continual basis. So if you got a sub capable of handling 400 WRMS, that means you can feed it 400 WRMS. Now some subs can be overpowered effectively, some cant. The number is there for a reason.

Next, the amp is what produces the power. You can have the best subs around, if you dont have an amp to properly push them it wont work good.

Generally speaking, a sub usually only needs 80% of its rated RMS to do its job. So if you got a 100 WRMS sub and run it at 80 WRMS then again at 100 WRMS you probably wont hear an audible difference.

Box. You can have the best amps and subs, if you got a crappy box you got a very large problem. Not all boxes are created equal!

Its all relative and all goes hand in hand.

The sales people should be able to help you with an amp selection after you figure which subs you want. Just remember the above information.

[white04alero]

well i understand that.. but im wondering if i have two 400w rms subs.. and i want to feed both 400w rms power.. do i need an 800w rms amp? or just a 400?

will it sound just as good?

[Ryan from Ohio]

Well if each one requires 400 then logically you need to add the sums of power requirement.

Keep in mind your wiring. How you wire the subs together deciphers what size amp you need.

If you wire them together at 8Ohms then you would need an amp capable of 1600WRMS @ 4Ohms to power.

But also, as I said earlier and to remember, just because you can use 800 WRMS, doesnt mean you HAVE TO ;)

[Gr1m]

btw u said ur amp blows, its not blowing it shuts off when it gets too hot to prevent damage

[white04alero]

no no no not like that its never "blown" on me.. it just really sucks.. not producing enough power for the sub.. stuff like that.. it blows as in not very good.

[antichrysler]

Ryan is right. 2x400WRMS subs = 1 800W RMS amp. Remember everytime you double the ohms on your sub you need double the power on your amp to feed it.

Also I cannot emphasize the box enough. Everyone thinks "hey if I buy two big subs the box doesn't matter" WRONG. The box is probably more important than having more subs. A good box with one 8" will sound better than a crappy box with 2 12"

[white04alero]

but ill be wiring them to 2 ohms like this:

http://www.crutchfield.com/learningcenter/car/subwoofers_wiring.html?suboptions=2%2DChannel%5F2% 2D2ohm%2DDVC&amptype=2%2DChannel

[antichrysler]

As long as you get an amp that's stable @ 2 ohms it'll be fine. Are the subs 400W RMS @ 4 ohms?

[Ryan from Ohio]

Ryan is right. 2x400WRMS subs = 1 800W RMS amp. Remember everytime you double the ohms on your sub you need double the power on your amp to feed it.

Also I cannot emphasize the box enough. Everyone thinks "hey if I buy two big subs the box doesn't matter" WRONG. The box is probably more important than having more subs. A good box with one 8" will sound better than a crappy box with 2 12"

Amen to that:

http://caraudiocentral.net/ryan/images/forsale/6thOrder2.jpg

Metering it this weekend!

[white04alero]

what are those? ports?

[Ryan from Ohio]

A good box with one 8" will sound better than a crappy box with 2 12"

Thats exactly what it is.

A box with a single 8" sub optimized to squeeze every last ounce of potential out of it, well SQ aimed that is ;)