Overheating Amp

[Jesse Dresselhaus]

So here's what's going on. I bought this amp (http://www.audiosavings.com/products/2-channel-Car-Amplifier/SONY-XPLOD-1200-WATT-2-CHANNEL-CAR-AUDIO-AMPLIFIER-AMP/XM2002GTRRB.aspx) and a thrift store about a month ago, and two unknown 10" subs in a sealed box. My friend thought they were Alpine's I believe. I wired them like this initially:

It was generally not great. Things varied wildly by genre, and I needed to EQ drastically in order to get things to sound how I liked. Today, I tried wiring it like this:

I thought--why not? Maybe it would work. It did. 10x louder, got rid of the problems between genres, all boominess, and needed almost no EQ. However, shortly into some hard rocking, it cut out, and was quite hot to the touch (not hot enough to burn my hand though). It turned back on right when I restarted my car.

Question--why did it overheat? Isn't it running at a lower load? Was the gain set to high, or was it wired wrong? Is this how I should be wiring it, or is there a way to determine that without knowing the specs of my subs?

Would love some feedback. It sounds great right now But don't want to do damage.

[SnowDrifter]

For starters it's a sony xplod. It's cheap. Strike one. It's a class a/b - lots of heat. They run warm by design. Strike two

Have you verified your final ohm load with a multi mter?

The difference in sound between the two setups makes me think there is something amiss. On paper, it's the same amount of power either way.

How shortly are we talking about? 5 seconds? 5 minutes? Where is your amp mounted? Does it have ventilation?

[Jesse Dresselhaus]

Throwing this out there, I am quite un-knowledgeable. I also don't desire to have the best system

I have not verified my final ohm load. How would I do so?

Shortly was about 30 minutes. My amp is mounted on top of my sub, in my trunk. Not a lot of ventilation.

It didn't overheat before the re-wire however. Something happened when it was re-wired.

[BigManAC]

If you re-wired it make sure you have a good ground. If you have a multi meter that does ohms then connect the positive and negative going into the amp and see what the ohm load is there.

[SnowDrifter]

Not saying strike 1 as in the amp sucks. Understand that I'm not one to overhaul your setup because of a problem. Some members on here will do that, I don't.

Strike - meaning strike against your problem

Do you have a multi meter? There should be an ohms or resistance setting on there. The symbol looks like this: Ω

Set it to that, the lowest value it will go. Then touch the leads together. If it reads 0, you are good to go. If it reads anything else, remember that number.

Unhook your speaker wire from your amp, touch the positive side to the red lead, negative side to the black lead. Note the reading. Remember that number you remembered earlier? Subtract that from the reading you just took. Post it back here

Of note: If you are getting an erratic reading, re-do this test in a quiet place free of drafts

[Jesse Dresselhaus]

I don't have a multimeter :/ I can get my hands on one if that's necessary. When I do, I'll post the results back.

If there are any other things or suggestions that I can do, let me know.

[youngbass98]

From the sounds of it is that you dont know what the ohm load of your sub coils are so you could be wiring below the amps stable ohm load

[SnowDrifter]

IMO, a multimeter should be part of anyone's audio toolbox. It's a very powerful tool to diagnose things and without it, the only other thing we could do is throw money at your problem. Replace this, relocate that, re wire this thing that way, hoping that it will work. With a DMM, we can diagnose and be sure of the problem.

Regardless of where this goes: I'd relocate your amp to somewhere that has lots of air flow. As I said before, class a/b amps run pretty warm by design, and need cooling

[Jesse Dresselhaus]

A DMM will be on my to-buy list!

My roommate informed me that he believes that my subs are 4-ohms each, in which case my amp would be running at 2-ohms which is 2-ohms less than it is rated to run in, according to the specs.

Bummer. It sounded incredible. I switched it back right now and it was very lack-luster.

I'll confirm that with a DMM later.

[SnowDrifter]

Running below rated is a sure source of heat