Plugging 3 8ohm Cabs to 4 ohm Amp.

[Tim Skaggs]

View attachment 4168238 What kind of damage can I be doing to my Bugera Head. Does the amp being 2k Watts make a difference.

Continually running a 4 ohm minimum load head into a 2.67 ohm load will eventually stress / heat something to the point of failure. Protection might save you a few times until it fails, keeping the amp in shutdown mode until repaired.

As others have said, the amp is not 2k watts RMS at four ohms. If it was, when you used only two speakers, you could have been driving each speaker well above its 500 watt rated power. Lots of folks have used an amp more powerful than the rated power handling capability of their speaker(s), but they use common sense and their ears to tell them when the speaker is stressing & limit the volume. Using an amp that has twice the power output of the speaker power handling capacity makes the situation a little more precarious. It’s possibly your good luck the amp doesn’t put out 2000 watts RMS at 4 ohms or you might have already let the magic smoke out of a speaker or two.....

 

[SemiDriven]

We promoted a double feature with Towering Inferno and Earthquake. It was promoted as the “Shake and Bake” double bill.

Ignoring manufacturer specs will have the same result.

 

[g-dude]

I am not debating, just asking someone to explain / illustrate the math. Tried to post a diagram but it didn't work...

1 / [(1/OhmCab1) + (1/OhmCab2) + (1/OhmCab3) +....]

That is if you’re talking parallel. Series, just add the Ohm.

So in the case above, you’re talking about:

1 / (1/8 + 1/8 + 1/8) = 1 / (3/8) = 8/3 = 2.6666666666666666

 

[Chad Michael]

1 / [(1/OhmCab1) + (1/OhmCab2) + (1/OhmCab3) +....]

That is if you’re talking parallel. Series, just add the Ohm.

So in the case above, you’re talking about:

1 / (1/8 + 1/8 + 1/8) = 1 / (3/8) = 8/3 = 2.6666666666666666

Yes. I get it, you get it, aged horse gets it, I know the math and how it applies. Was just looking for some help to explain it to others who don't get it (see post #37) Thanks g-dude, this will help others in the future.

 

[dbase]

I was hoping for a video of the detonation... kinda feeling let down.

 

[abarson]

I feel let down .. was hoping for a video of the detonation.

OP does not appear to be in Texas and doesn't need the extra heat of a burning rig.

 

[g-dude]

Yes. I get it, you get it, aged horse gets it, I know the math and how it applies. Was just looking for some help to explain it to others who don't get it (see post #37) Thanks g-dude, this will help others in the future.

I don’t have a good analogy using math, but I think the best way to help others understand it is to think of water.

If you have only one drain hole in a bathtub, water is going to flow through at a given rate. Add more holes in the bottom, and the water will drain faster.

The pressure pushing through that single drain hole is going to be higher than if you have multiple drain holes.

Now, if your goal is to have water coming in the bathtub and leaving at the same rate, you need to make sure that the faucet’s output can match up to the speed as which the water drains. Otherwise, you end up with a dry bathtub and the pet shark you’re keeping in there will die.

This may not be a perfect analogy, because I’ve never taken an engineering course, much less one on electrical engineering, but it’s probably close enough for government work. Unless one is in the Army Corps of Engineers.