Amp Fuse/Gain Help

[fury 10+ year member]

Ok.. so I got my sub/amp/cd player all installed for me because I was too lazy to mess with it. I paid about $140 bucks for everything (amp kit + labor). I had the rest of the stuff. Everything worked fine, it pounded hard and sounded great. One of the first things I found that bothered me was that all of my bass control was within my remote bass knob mounted up front. Now, considering almost everyone tells me that they dont even use their bass boost on their amp.. I found it odd that if I had my bass boost down to minimum.. I had no sub movement at all.

Now before I continue I feel it's necessary to tell you all what I'm running and what was installed.

Power Acoustik 3000db Amplifier (rated 2300 rms @ 1 ohm -- 160 amps peak according to manual)

1 15" XXX in a sealed box wired to 1 ohm

Alpine CD Player 9827 (something around there)

Using a 4 guage amplifier kit (that's what the installer said he was going to use) I told him that it was going to be pulling those kind of watts and that many amps.. he said it would be fine. I also didnt think it was that big of a deal because the wire length of the 4 guage is not too excessive. Whatever though, I'm not the installer he is.

So.. I get the idea of properly setting my gains based on the tutorial found in the amp section. If I'm running the entire bass off my remote bass knob, honestly the gains can't possibly be set right. I do the calculations of 2300 x 1 ohm figure out to need a bit shy of 48 volts. I download the test tones and burn them on a cd. Ok I figure I'm ready to go. I get out there and set up all my settings to max music levels. Headunit to 23/35 with +1 bass and +3 treble no mx subwoofer level at max. I set the cd to the 50hz test tone and hit pause. So I head into the trunk and start looking at the amp settings.

Subsonic turned as low as possible 15hz. Bass boost turned to 0 db. Low pass filter turned from 150hz to what I perceive as roughly 80-90hz ( I figure the xxx can handle it). Now the gain. I turned it all the way to minimum at first so I could just turn it up to get my 48 volts. I have a digital multimeter that my dad was letting me borrow. I set it to 200 volts in order to adjust the gain. Next I grab some alan wrenches and take out my speaker wire.

Ok so now I've got the multimeter plugged into the amp and tell my lady friend to hit play on the cd player. No reading. Hmm, try it again, no reading. Ok well I took out these copper pieces that hold the speaker wire in and I figure the connection might not be made to the multimeter leads. So I try that.. no reading.

OK now I'm frustrated. I plug the speaker wires back in and alan them back down.. try some music, no sub movement.. just great. A friend tells me I might have blown a fuse, sure enough under the hood the amp power wire fuse is blown. First I say WTF, then I realize I probably should have turned the car off before disconnecting the speaker wire. Ok my mistake, so I pull the fuse out. 5AG 80 AMP?? What the ****? 80 amp fuse seems a little small to me??? Maybe I'm missing something, what relevance does the 5 AG have to the 80 amps? 5 x 80 = 400 amps which seems more feasible, but way too much for a 4 guage wire. So what the hell happened here, did he **** me over and install a way too small fuse/amp kit and try to cover it up by turning my gain to nothing and making me use bass boost to get about 1/3rd the power I should get. Or am I overreacting and is 80 amps enough (uh I don't see any way how, but .. ). Regardless, I'm getting another replacement fuse, my amp gain is not set right, and I'm subless at the moment. Any advice, suggestions, what I did wrong, is welcome.

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[sumone 10+ year member]

Whatever though, I'm not the installer he is.

...eh, sometimes your common sense can prove to be of better use than his knowledge of car audio...

1. how long is your run of 4ga?

2. If AG=AGU, then I think AGU fuses only go up to about 80 amps, so maybe he was just using what was in the wiring kit...otherwise he would've wanted to grab probably an ANL fuse holder & use a 150 Amp fuse.

3. as far as what you did wrong, can't tell anything yet, since, in essence, nothing was really tested cause the fuse was blown.

 

[sumone 10+ year member]

use this to determine if 4ga is suitable

 

[JimJ 5,000+ posts]

So what the hell happened here, did he **** me over and install a way too small fuse/amp kit

yep...sorry to say it, but yeah. 4awg has no chance in hell of safely carrying the current needed for a 2.3kW system, whether or not your installer knows it or not.

To put it in perspective, I'm currently running 1.7kW total, and I'm using 2awg wire. Barely. I have a 200A ANL fuse under the hood, which is really the maximum you can get away with for 2 gauge. For 2.3kW, you're looking at 1/0 guage, easy. Several hundred amps of fusing underneath the hood.

 

[DBfan187 5,000+ posts]

Don't you keep the sub hooked up to measure the voltage? *earplugs*

 

[fury 10+ year member]

Not from what I understood, but maybe. And thanks for the site. The site says I could carry about 1600 watts without voltage drop with the wire length.. sigh the fuse was still way too small though, says 150 max amps on the wire.

Edit: Not very sure on the wire run, I would say not much over 10 foot, 13 max.

 

[JimJ 5,000+ posts]

no, you want to disconnect the speaker during the test, so it's not exposed to the test tones...

 

[sumone 10+ year member]

basically you just want the amp to put out X volts. AFAIK, you don't want the amp to see an impedance as it may offset stuff (just guessing).

 

[JimJ 5,000+ posts]

[edited out]

~jack