Piggybacking speaker cabs?

[toejam]

I've got two vertical Jackson 2x12 cabs (they're both 8 ohms), they've got two jacks each, one for input and one for output. I assume I could use them, one piggybacked off the other, with the new THD Univalve amp I'll be getting that only has one speaker output. When I use the cabs now with my Mesa F-30 combo, they both run off the 4-ohm outs of the Mesa... since two 8-ohm cabs together make 4 ohms.
My question is: What impedance would I set the Univalve to since it's only got one speaker out? There is a switch on the Uni for impedance... in the up position, it's 8 or 16 ohms; down, it's 2 or 4.

I've also got a Crate 4x12 that's 8 ohms with two jacks. I assume I could also piggyback another cab off of this (say I wanted to use another 4x12 or maybe one of the Jackson 2x12s with it), and I've got the same question regarding ohm selection.
I assume the two 8-ohm cabs together would still put out 4 ohms, but I'm not sure since one would be slaving the other and only one would technically be plugged into the amp. I'm just a little confused. [img]/images/graemlins/help.gif[/img]

[buzzsaww]

Re: Piggybacking speaker cabs?

I may be wrong but I thought the jacks on 4x12 cabs are wired for series. ie. 2 8ohm cabs piggybacked would give you 16ohms.

[toejam]

Re: Piggybacking speaker cabs?

Ah, maybe. That's what I'm unsure of.

[Chuckracer]

Re: Piggybacking speaker cabs?

Look at it this way: Series doubles and Parallel halves.

So, if you have two 8 ohm cabs in series, which you will if you daisy-chain them, you have 16 ohms at the amp.

[toejam]

Re: Piggybacking speaker cabs?

Got it. Thanks, Chuck! [img]/images/graemlins/smile.gif[/img]

[Cleveland Metal]

Re: Piggybacking speaker cabs?

Must.... buy..... DVM..... Know.... actual... Impedance.....



Hehehe... It's sorta nice to know...

[toejam]

Re: Piggybacking speaker cabs?

Yeah, I should buy one, huh? Hehe

[siggy14]

Re: Piggybacking speaker cabs?

most cabs i know of usually do it in parallel over series. Another solution is to buy a hotplate, they have one input and you can output to two speaker cabs.

[toejam]

Re: Piggybacking speaker cabs?

[ QUOTE ]
most cabs i know of usually do it in parallel over series.

[/ QUOTE ]
Yeah, that's what I kinda thought, too, but wasn't all that sure.
And the amp does have its own Hotplate built in, but an external unit would definitely be an option for easily adding an extra cab. Thanks for the tip!

[siggy14]

Re: Piggybacking speaker cabs?

[ QUOTE ]
[ QUOTE ]
most cabs i know of usually do it in parallel over series.

[/ QUOTE ]
Yeah, that's what I kinda thought, too, but wasn't all that sure.
And the amp does have its own Hotplate built in, but an external unit would definitely be an option for easily adding an extra cab. Thanks for the tip!

[/ QUOTE ]

Cheap solution, buy a little box, 3 input jacks from radio shack and3 speaker cables. Make one jack the input and wire it to the two others in parallel or series to the other to jacks, drill three holes in the box, secure the jacks to the box and you have an instant splitter.

[lerxstcat]

Re: Piggybacking speaker cabs?

That's a single-valve amp though. I can see daisy-chaining
the two 212s, but are you really thinking of running the 412 AND another cab? Seems like you might be giving the Univalve quite a bit to drive. Running 2 412s off of a 20-watt head? Maybe you can do it but what's the point?

[toejam]

Re: Piggybacking speaker cabs?

[ QUOTE ]
That's a single-valve amp though. I can see daisy-chaining
the two 212s, but are you really thinking of running the 412 AND another cab? Seems like you might be giving the Univalve quite a bit to drive. Running 2 412s off of a 20-watt head? Maybe you can do it but what's the point?

[/ QUOTE ]
Oh yeah, that's a good point, Rich. I probably won't do that anyway. I'll mainly just use the 2x12s at home and the 4x12 to take out to jams since it's a lot lighter to carry around.