#1
so my band could be using just one guitarist in the future, if this happens i wanna run two cabs, but only of one head. ive seen a few bands do it with only one guitarist so i thought id give it a shot.

the amp has a switch to run either 4, 8 or 16 ohm cabs. and two outputs. if i were to run two 8ohm cabs, what would i set the ohm switch to on the head? and what could be damaged in doing this?
#2
Do it right and it'll work fine. Do it wrong and you end up damaging your amp.

If the cabs are 8 ohms, here's what you need to do:

If you run them in series, set the amp for 16 ohms.

If you run them in parallel, set the amp for 4 ohms.

Most amps can also run what's called a "safe mismatch." That's where your cab is at a higher ohm rating than the amp is set to. For example, say your amp is capable of 8 ohms, but your cab is 16 ohms. This shouldn't be a problem. What you don't want to do is, for example, connect a 4 ohm cab to a 16 ohm amp. This would spell disaster, since the amp would overheat and fail. Check the manual of your amp for specifics. Hope this helps.
#3
Running a safe mismatch isn't ideal though, I never tried it on amps, but I know with other electrical components, you get best performance when resistances match
#6
Quote by eurotrashed
Running a safe mismatch isn't ideal though, I never tried it on amps, but I know with other electrical components, you get best performance when resistances match


That's why it's called a safe mismatch - because it is safe. Funny that both my Mesa and Peavey manuals say it's okay to run a safe mismatch.
#7
Quote by JimPlaysGuitar
Wow, you're all complicating it. When using two 8ohm cabs, set the head to 4 ohms.


Sure. If you want to absolutely simplify it as much as possible, it can be done that way, since we'll either present a 4 ohm or 16 ohm load to the amp. The first one is the correct match and the second is a safe mismatch. However, there may be other occasions where he wants to do the same thing with an amp that is fixed at 8 ohms. Putting those 2 cabs in parallel would feed the amp's signal into a 4 ohm unsafe mismatch.

Fact of the matter is, you can tell him how to do it and then keep answering the same question over and over again, or you can teach him and others how to do it for themselves. It's called teaching.

The bottom line:

Experiment with correct and safe mismatches. They will have an effect on your tone.
#8
Quote by KG6_Steven
That's why it's called a safe mismatch - because it is safe. Funny that both my Mesa and Peavey manuals say it's okay to run a safe mismatch.


I didn't say it wasn't safe, I just said it isn't IDEAL. Electrical components work best when resistances match. If you want I can show you some formulas that explain this.
#9
Quote by JimPlaysGuitar
Wow, you're all complicating it. When using two 8ohm cabs, set the head to 4 ohms.
No kidding. 4 ohms man.
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#10
Quote by JimPlaysGuitar
Wow, you're all complicating it. When using two 8ohm cabs, set the head to 4 ohms.



i did this yesterrday though. and it seemed like i had to drive my amp too hard to get it loud.


im a fair noob with circuits and what not, but i think slighly remember some of that **** i did in physics haha. would running the cabs in parallel be having each hooked up to an output on the amp? and series be amp->cab->cab ?? im determined to work this **** out.
#11
mangz_adrits real simple.2 16hm cabs run it at 8.2 8hm cabs run it at 4..got it.plus ot doesnt matter if your the only guitar in the band.You get a good enuf 50 watt or 100 watt.All u need is 1 4/12 cab.Put 2 or idealy 4 300 watt ev's black label speakers and no more worries..Of u got the cash do it.
#12
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