HELP! What amp do i buy! will it break my cab?

[JDKslice]

Hey dudes!
iv been after a new bass rig for a while and finally an offer has popped up i like the look of!
An ashdown Mag410t cab (the 8ohm version) power handling 500watts
and an Ampeg SVT450

My question is!...

At 4ohms the Ampeg puts out 450Watts
and at 8ohms it only puts out 275 watts

The cab is 8ohms so if i run the head at 4ohms will this break the cab?

the whole reason im upgrading is volume and i really want the SVT450 yet dont want to get into the 2 cab territory!
Help a brother out!
Cheers

[Musky]

SS amps will put out a specified wattage into a particular load. In your case that's 275w into 8 ohms. It does this automatically without any switching needed*. It will run happily down to a minimum load , again in this case that's 4 ohms, so you could run two 8 ohm cabs without fear of any damage to your amp. Dropping below the minimum load will likely result in an expensive repair bill.

If you imagine the amp as a water tank with the cabs connected via pipes, you can imagine the water flowing out to the speakers. How fast that water runs out depends on how greatly the water is impeded. The cabs impedance is measured in ohms, so with the higher 8 ohm figure you'll get a specific wattage (275w). When you reduce the impedance more 'water' will flow, so you'll get more watts. Why not go to an even lower impedance, say 2 ohms? Because the pipes (wiring) can't handle that kind of current flow - hence why a minimum impedance is stated.

So to answer your question, no you won't break the cab.

Oh, and the volume difference between 450w and 275w isn't very much at all. It's very much in 'only just noticeable' territory.

*Unless you happen to be using an Orange Bass Terror!