Run 2 subs off MONO amp!?

[migga]

What happens when you run TWO subs off a MONO amp? Cause the guy at circiut city is telling my friend what i believe to be a bunch of BULL SH*t...... he is telling him that the amp pushes half the wattage when it is hooked up to only one sub........and that it runs at full wattage when hooked up to both subs.....could this be why both his subs have blown twice????? Its a Bazooka EL1500 amp and 2 MTX 6000s (12s). Please let me know what ya'll think.

migga

 

[B94Sport]

Mono amps are called mono, not because you can/should only run one sub off of them, but because they only have one output channel (non-stereo).

As for your question: When you run two subs off of a mono amp, theoretically it can push twice the wattage, IF the subs are wired in parallel, witch drops the impedance, and IF the amp is stable at that lower impedance. Now, if you wire the subs in series, which raises the impedance, then the amp's going to push less wattage.

That amp is stable to 2 ohms, where it puts out 500 watts, as opposed to operating it at 4 ohms, where it puts out 350 watts. So cutting the impedance in half on that amp does not double the wattage, but it does increase it. Does your friend have the dual voice coil or single voice coil version of the 6000? If it is dual voice coil, then you would need to wire the voice coils in series and the subs in parallel, which would give you a 4 ohm impedance and 350 watt output, but those subs take 250 watts RMS each, so hopefully he has the single voice coil version. If they are single voice coil, then you can wire the subs in parallel and get a 2 ohm load on the amp, giving you 500 watts RMS from the amp, just the right amount of power for the subs.

Hope this helps you out!

 

[migga]

he has the single voice coil i believe.......so how would i wire them in parallel?

 

[B94Sport]

Run a wire from the positive output of the amp and another wire from the negative output of the amp, and split each of these wires into two. Connect the two positive splits to the two positive terminals (one on each sub) and the two negative splits to the two negative terminals (again, one on each sub.).

OR

You can run a wire from the positive output of the amp to a positive terminal on one of the subs, and a wire from the negative output of the amp to the negative terminal on that same sub, and then from those two terminals, run one wire each - one from the positive terminal on the first sub to the positive terminal on the other sub, and one from the negative terminal on the first sub to the negative terminal on the second sub.

Basically, connect all of the negative outputs/terminals together with wiring, and connect all of the positive outputs/terminals together with wiring. But DO NOT connect negative to positive or vice versa.

 

[migga]

the way he has it hooked up is with two wires coming out of each terminal.......going to both subs..........that sound about right?

 

[B94Sport]

Yes, that will work too

 

[migga]

ccool......so the amp wouldn't be the cause of his speakers blowing?

 

[JTang]

Your salesman is right if he has DVC subs set up at 8 ohms each. He'd be wrong if each was at 4 ohms each. There are three ways he might have blown his subs:

1. Speakers do not adhere to the RMS ratings as a hard and fast rule. They will change if the box is smaller or larger, and if it's in a sealed, vented, or bandpass box. So it could have been that his box was not the right size and skewed the numbers.

2. If he has DVC subs, he might have set them up as 2 ohm subs, then wired them in parallel down to 1 ohm. This is bad for amps that can't handle it, but will easily take out a sub much faster.

3. His box was totally wrong for the subs, and the subs lost control, and grounded out on the voice coil.

In honest opinion, though, if he's from Circuit City, he probably didn't know what he was talking about when it comes to the math for wiring. While the installers know their stuff, the salesman don't know much there.

 

[migga]

they are single voice coil in the MTX box they were on display with. they told him he ran his "DBASS" on his HU for too long and too hard.