I'm new to all of this...

[Kernel5]

And I'll be honest: I don't know diddly-squat about audio systems. I have questions that I don't know how to answer. So I'll make it simple.

I have two used Rockford Fosgate 12" subs. The back of them say "Dual 4 Ohm, 400 watts RMS, and 800 watts Peak, product number RFP4212. The amp is an American Legacy,that says two channel, 800W high power amplifier on it, product number LA590.

When the guy sold them to me put them all in, they rumbled like crazy and made my college parking pass hang from my mirror shake violently. I had the subs wired normally before, but a few days after I got them, they guy who sold them to me bridged them, because I apparently crossed a wire somewhere, and fried something in the amp. Now, with everything hooked up right, my parking pass does not violently shake like it used to, because when I try to turn it up that high, the amp's warning light comes on, and the subs shut off, etc.

My question: Is the amp screwed? Was the amp screwed from the beginning due to some incorrect wattage balancing, or was it my fault? How am I supposed to interpret all those numbers up there?

Any help is greatly appreciated //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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[Kangaroux 5,000+ posts]

sounds like your amp is seeing too low of an impedance load. If they are bridged, they should be wired like so:

 

[i2ain2thunder 10+ year member]

first make sure they are wired correct. like shown above. If you've fried something in the amp I don't know how it would still run just bridged....have you tried wiring one of the subs to each of the channels to see which channel is mest up?

 

[i2ain2thunder 10+ year member]

also try wiring each sub to make sure those are working correctly too, you could always have a blown voice coil on the sub. test each sub and make sure they sound good and the same.

 

[i2ain2thunder 10+ year member]

the subs should be wired in parallel to test each channell at 2ohms.

 

[i2ain2thunder 10+ year member]

To be honest though if u want more damage to be done power those subs properly, if you got 150$ you can prob pick up an amp that'll do 400watts rms at 2ohms per channel. That amp is garbage.

 

[Kernel5]

Like I said, I don't know diddly squat guys. That picture makes absolutely no sense to me, I don't know what a low impedance load is, and I don't know how to run things in parallel. I do know that before they were bridged, the left sub barely produced vibes, then once they were bridged, both of them worked the same.

 

[i2ain2thunder 10+ year member]

Lol ok we'll take it slow. first take the subs out of the box and undo the wires from the subs to the amp. take one of the subs which you will notice has 4 inputs for wire probally 2 on each side of the sub. Each side should have 1 + input and 1 - input. Now you should also notice on the amplifier there is also 4 inputs 2 of them will be + and 2 will be -. They will probally be alligned like so + - + - and they might even say + - channel 1 and + - channel 2. What you want to do is take the subwoofer. Now wire the + on one end of the subwoofer to the + on the other end of the subwoofer. take some more wire and wire the - of one side to the - of the other side. Then take some more wire and on one side of the subwoofer, wire the + (which also has wire in it from the other side) to one of the + on the amplifier input. Then repeat this with that same side's - to the - for that channel in the amplifier. So it should go Wire from positive 1 on the sub to positive 2 on the sub to positive 1 on the amp. and the negative should be the same wire from negative 1 on the sub to negative 2 on the sub to negative 1 on the amplifier. This is what we call wiring the sub in parallel and what it does is bring you're 2x4ohm voice coils into a 2ohm load. then that 2ohm load is hooked up to one of you're amplifier channels which operates safely at 2 ohms. this will test the subwoofer and the amp channel. Do this and listen to the sub, then take the sub and wire it the same way to the other channel.(move the wires from + - channel 1 to + - channel 2. and listen to the sub. if it sounds different when you do this then one of the channels is mest up. If it sounds the same and you don't hear distortion from your subwoofer then you're subwoofer is probally fine, you'll want to repeat this process with the other subwoofer if that sub sounds different from the other sub then you know theres a problem with one of the subwoofers.

 

[i2ain2thunder 10+ year member]

When you hear something bad you will know it. If the sub sounds bad switch it to the other channel if it then sounds good then your amp has a mest up channel, if you're sub sounds bad no matter what channel it is on the sub is prob mest up. But if that is the case theres still 1 more test we can do (since your friend is convinced the amp works fine bridged.) we can test both subs wired bridged to the amp. You should do that test I showed you though wire each sub parallel to each channel and find out what is mest up. Hopefully it is the amplifier, because that thing sux anyway you should get a better one.

 

[Kangaroux 5,000+ posts]

NEW MB Quart ONX1.1000D Class D 1000W RMS Amplifier/Amp | eBay

and if the wiring kit youre using is meh then pickup this:4 Gauge Amplifier Installation Kit

 

[i2ain2thunder 10+ year member]

NEW MB Quart ONX1.1000D Class D 1000W RMS Amplifier/Amp | eBay
and if the wiring kit youre using is meh then pickup this:4 Gauge Amplifier Installation Kit

My buddy's roomate just bought that amp, its a decent amp.

 

[DeathByWaffle 10+ year member]

Rofl. I was pushing 2 12" L7's 750 rms each. With a mtx thunder 6500d Power 14.4 VDC ,2 Ohm Load 775 w x 1 ,4 Ohm Load 450 w x 1.

Those things blew all 3x25 amp fuses. Haha. I had my dads suburban flexin. Was intense. Then boom. Dead. haha. Good thing I just stuck in 3 new fuses and it works like a beast again.

 

[Kernel5]

Alright. It took a bit, but I managed to find time to check the.... everything. Both subwoofers are in good working condition.

As for the channels on the amp, it goes like this:

+ + - -

the first pos and the last neg are the terminals I'm using to bridge the subs into. If I try the first pos and the first neg, or the second pos and the second neg, it comes in with much less power. If I try the second pos and the first neg, I get no thump at all.

I'm saying it's a safe bet that the amp is fried, correct?