Question about new 2x12 set up with 2 Channel H

[Nineteen]

Hello all!

New to this forum, and I just had a newbie question about my 2 Channel H head.

I've been running it through a 4x12 cabinet, but am planning on switching to 2x12s instead.

Would I route cables from both the SPKR OUT and EXT, one to each 2x12?
And if this is the case, does the Impedance Selector regulate the impedance output for both of these output jacks?

Thanks for your responses!

- Andrew

 

[Bluesboy998]

Andrew are you going to run 1 2/12 or two 2/12s

 

[Nineteen]

I want to run two 2x12s at once.

 

[Bluesboy998]

Ok assuming they are both 8 ohms you could plug 1into speaker out and the other into ext out and put switch to 16 ohms.Or you could use a y cord from speaker out to both cabs and leave switch at 16 ohms.

 

[dsenoj]

With 2 cabinets in parallel that are 8 ohms each, your switch should be set to 4 ohms.

 

[Nineteen]

Okay, thanks for the responses!

Now using the Speaker out and the Ext out, does that wire my two cabs in parallel?

 

[Boogie]

It's simple, plug the 8 ohm cabs into the 8 ohm outputs on he amp. No second-guessing required. If you have the impedance selector switch, you select 8ohm. The switch will connect your cabs in parallel and to the proper transformer tap. And if you set the wrong setting, nothing bad will happen. In fact, you may find a mismatch to sound better. Give it a try.

 

[dsenoj]

The speaker out and ext out jacks are parallel. You can see the 2 channel H manual online at http://www.prsguitars.com/csc/manuals/PRS_2CH_Amp_OwnersManual.pdf. They mention using two 8 ohm cabinets in the manual.

 

[Nineteen]

Ah okay perfect!

I was having trouble reading the manual online, it wouldn't show the second page, but after I downloaded it and opened it on my desktop, the whole thing read fine.

Thanks so much for your responses!

 

[Boogie]

The important thing is to remember that you don't have to do any math. Read the label on your cab(s). If it says 16ohms, then select 16 ohms setting with the impedance switch. Use the same impedance cabs (all 4/8/16). So, even though you might have two 16 ohm cabs, just plug them in and select 16 ohms. The math is calculated for you on the inside.

 

[aristotle]

The important thing is to remember that you don't have to do any math. Read the label on your cab(s). If it says 16ohms, then select 16 ohms setting with the impedance switch. Use the same impedance cabs (all 4/8/16). So, even though you might have two 16 ohm cabs, just plug them in and select 16 ohms. The math is calculated for you on the inside.

Hey Boogie... In this case, I think that they really do want you to do the math. So, if you're hooking up two 16 Ohm cabs, you set the selector to 8 Ohms. There are counter examples with other amps, but in this case, they want you to compute the combined impedance of the two cabs yourself and set the selector accordingly. At least that's what they say in the manual (and it's sort of the industry standard also...) Problem is, when the jacks are hooked up in parallel like they are here, the amp would have no way of knowing if you have one or two cabs hooked up. It'd just know the combined effective impedance it sees.

 

[László]

Boogie, I'm no scientist, but I think Aristotle is right.

This kind of thing can definitely get confusing!

 

[Boogie]

Actually, for the models with a switch, you're probably right. Those with discrete 4/8/16 ohm outputs, are probably exempt. Using an old Twin II schematic for reference (it's what I have handy) there's an elaborate series/parallel switching scheme that combines two 8ohm in parallel and connects to the 4ohm tap and 2-8 ohm outputs connect in series and also use the 4 ohm tap. Only a single 4 ohm output uses the 4ohm tap. This is very typical. Mesa/Boogie is similar in that on old Mark series, there's really only an 8 ohm tap on the transformer and the 2-4 ohm outputs are really in series. The amount of confusion by the general public is HUGE. Without schematics to confirm - or someone taking good gut shots - we can't know for sure.

My bad guys. I didn't mean to lead anyone down the wrong path.