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Another Amp Fuse question.


longlivetheZ
12-22-2009, 06:00 PM
I have a Hifonics Brutus amp pushing a dual voice coil Diamond Audio 10" sub in my 2002 Sentra Spec-V.

I had 2 of them hooked up running 1200W RMS for a little while but it was insane how loud it was so I took one of the subs out.

After running 2 subs for a day or two, then 1 sub for a few more days, it stopped working. I thought it was that the ground wire was loose because it obviously arced at the ground point (not on the amp) because the connector and wire were badly melted. So I redid the ground and made it more secure, hooked everything back up...nothing happened.

Found out the fuse was blown. No big deal. Change out the fuse and it comes on right away (I had to bridge the remote and 12V together to get it to turn on since something's wrong with my remote lead and I haven't had time to see what's up with it)...for about 3 seconds...then goes off again...another blown fuse.

What size fuse should I be using? I'm running 600W RMS to one 10" DA sub now through 4 GA wire. Or, worse yet, could there be something wrong with the amp? What size fuse should I have? If I have the right one, I'll replace it again and hook it up minus the speaker and see if it comes on and stays on.

PaulD
12-22-2009, 11:12 PM
the problem is, you have the DVC subs wired in parallel. When you had 2 subs it was probably a 2 ohm load and now it's a 1 ohm load. A 1 ohm load will draw twice the power, or try to at least.

longlivetheZ
12-23-2009, 12:02 AM
the problem is, you have the DVC subs wired in parallel. When you had 2 subs it was probably a 2 ohm load and now it's a 1 ohm load. A 1 ohm load will draw twice the power, or try to at least.

I thought of this. I too am a sound guy (PA's and the like) and thought that coil wiring/impedence could be an issue but why did it fry like that even when there were 2 running?

Also...would I be able to keep the wiring the way it is (to get the max power out of it, from what I understand) and get a different fuse?

Either way, I have a few days off coming up and I'm going to take the sub out of the box and make sure it's all good to go.

Thanks for the knowledgeable reply! I'll post the results in a few days!

PaulD
12-23-2009, 07:42 AM
well, just remember that power is volts X amps, when the power draw is heavy or the car is at idle the voltage drops - this can be caused by having the light, A/C haeter on as well. According to the formula, when the volts drop the current increases by a like amount, the amp just draws more current than the fuse is rated for.

longlivetheZ
12-24-2009, 08:04 PM
I noticed something today while out fartin' around with the thing:

The inline fuse that comes off the battery (the one that keeps blowing) is a 60A fuse...

The H fuse (or whatever the flat, 2 prong ones are called...) in the actual amp is an 80A fuse...

I'm starting to think I just need a bigger fuse...should I try a 70A?...80A?

Also...I'm considering adding a power capacitor to the mix. What should I look for? How do you buy these things? lol

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