Running Two Cabs With One Head

[Nick Lehman]

I have a 2 channel triple, planning on running two cabs at bigger gigs w/o a soundman.

Both cabs are 16ohm.
I have 16, 8, & two 4 ohm outputs. Mesa manual says safe to go 4ohm to 16 ohm cab in parallel.

This just seems kinda odd. Is it right?

Also, is it possible to simply split the output signal and send that to both? Or does that mess with the impedance?

Also thinking about doing an aby splitter so I can play through one side of stage on solo riffs then bust in both when drums and bass come in...

Thoughts?

 

[TRENCHLORD]

If your cabs have outputs for piggybacking then you can simply go from the amp's 8ohm output into one of the cabs (at 16ohm) then from the first cab into the other (a 16ohm).
Two cabs set at 16ohm each will combine for a total 8ohm impedance.

 

[Nick Lehman]

I thought piggybacking them caused the ohms to add up... 16+16=32??

Either way, the cabs are both Marshall.

One is a 1960a with 75's & v30's
One is an older jcm800 cab with 75's & hellatone 60L's

Im going to wire the older one up like the 1960, with the stereo switch.

I'm really partial to how my rig sounds with 16 ohms.

I could do 4ohm mono but never really liked the tone, its just different.

Ive also thought about running my orange th30 with the recto and utililize the stereo capabilities but the recto will way overpower the orange, being that its 30 watts max.

Plus that would take alot more cables and switch boxes, kinda overkill for thirty minute sets!

 

[cyber104]

TRENCHLORD is correct. Ohms add up in a series circuit. These cabs will be run in parallel

 

[Nick Lehman]

TRENCHLORD is correct. Ohms add up in a series circuit. These cabs will be run in parallel

Not to start a huge debate but by piggybacking you are referring to having 1 speaker cable running to one cab and then coming out of that cab to the next cab, right?
Isn't that in series? So the ohms would add up to 32 ohms. And your saying coming out of an 8 ohm jack and piggybacking through two 16 ohm cabs would not be a 32 ohm load on the OT?

Either way it doesn't matter because I don't have those types of jacks. I have the Marshall stereo jacks which have two jacks. They can be split the send 8 ohms to each half of the cab ( like if you wanted to run two heads in stereo) , or you have the option to run either 16 ohms or 4 ohms mono.

Normally I just come straight out of the 16 ohm jack and run it to the 16 ohm mono jack on my cab.

But now that I'm going to have two cabs, I'm kinda stumped.

I guess I will take Mesa's word for it and run two separate cables out of the two 4 ohm jacks I have on the back of the recto. Then send them to their own cab and plug them into the 16 ohm jack.

I'm just wondering if I will be able to tell a difference in tone.

I have tried running 4 ohms to the 4 ohm jack before and it sounded different to me.

I dunno, I just don't wanna fry my OT.

 

[Nick Lehman]

Would it be okay to just get a Y cable and come out of one jack to both cabs or would pose the same mismatch problem?

 

[Nick Lehman]

If your cabs have outputs for piggybacking then you can simply go from the amp's 8ohm output into one of the cabs (at 16ohm) then from the first cab into the other (a 16ohm).
Two cabs set at 16ohm each will combine for a total 8ohm impedance.

I just talked to my amp tech and he said the same thing, so I guess i'm just confrused a bit. electrical stuff isn't my strong point.

unfortunately I cant do this because of the stereo jack dealy.

He said I could do what Mesa says and run parallel out of the 4 ohm jacks

But he also said I could split the 8 ohm signal with a Y cable and send to both cabs that way!

YAY!!!! screw 4 ohms!!

 

[cyber104]

Just because you are "daisy chaining" cabinets together does not mean they are in series.

There are some good articles out there describing the difference between series and parallel - you might want to consider giving them a look

 

[elvis]

The absolute best thing you could do is get an inexpensive multimeter with Impedance (Ohms) capability. Hook up cabinets however you choose and measure the impedance. That will ensure that you know what impedance you are hooking to your amp and also you will better understand how impedances combine. It will help you spot a miswired or damaged cab as well.