I was trying to figure out what size fuse that I will need for my amp. I have a 400w sub with a 200 Watts X 2 Channels @ 4 Ohms Bridged amp.

I found a formula that asked how much pull was going to be on an the amp, max RMS from the sub. Max from the sub would be 400w, but the max of the amplifier is only 200w when bridged. Would that mean that the formula is run off of 200w?

Formula:
max watts / 12v * class amp (A & B = 1.4, T & D = 1.2) = fuse amperage

Mine?:
((200w / 12v) * 1.2) = 20a fuse

TIA

 

This line is confusing the hell out of me. Don't worry about any sub specs at the moment because they won’t influence how much power the amp will be putting out or how much current it will be pulling. If your amp is doing 200 watts x 2 @ 4 ohms bridged does that mean it's a 4 channel? What exactly are you trying to ask (fuse size for the amp's fuses?)?

As for the formula, yes that’s accurate as a baseline but you should generally stick to the manufacture’s specs for fuses.

 

One, what fuse? In the amp or the amps power wire? Two, ignore that formula, it assumes you know the wattage, and for 90% of the amps out there the wattage they advertise is just numbers, not really represent of what the amp will do.
What is the make and model number of the amp? If it's the fuse in the amp, that's what we need. If your talking about the fuse in the power wire, look at the amps and add the fuse's ratings together. If one 20A= 20A, two 20A= 40A.

 

Oops, sorry. The amp is an Autotek SS-400.4. It's a 4 channel amp. I'm only running a single Niche Audio 10" (NW1000HD), it's specs are 800w RMS and 400w continuous.

I'm redoing the wiring to the battery because it wasn't setup correctly in the first place. I was wondering what size inline fuse that I need to run.

Another question. Since the amp can get near the 800w while being bridged, should I go for a different amp?

 

OK, then add the values of the fuses together. If one 20A fuse, put a 20A fuse in the power wire, if two 20A fuses, use a 40A fuse in the wire, ... Do this for anything you're powering off of the wire. So one amp with a 20A fuse, another with a 30A fuse, and a neon light with a 5A fuse, Don't think you can get a 55A fuse so use a 50A.
Got it?

 

I believe so. Since I only have one amp that contains a 20amp fuse (I think), then i will only need to put one 20a inline fuse,however, if I had to amps with one 20a fuse each, I would need 40a inline?

 

You got it...
I should add to make certain the power wire can handle, at a minimum, the current the in-line fuse is rated for. So don't use a 50A fuse on 22 gage wire.

 

Sweet. Thanks dude.