2 Heads on one Cab?

Question

I have two Half stacks, one Marshall and one Kustom. My question is can I plug the two heads into each cab?

What I want to end up doing is have an ABY switch from my guitar straight to the Marshall head, and then the other goes to an effects processor, and have sound coming from both cabinets at the same time.

Are there any problems that I could/will face having 2 heads into a single cab? And should I just go with the ABY switch to each half stack as it is

I want to be able to use one head at a time. When I'm playing some nice classic rock, have my switch to the Marshall head, and then if I come up on a song that needs effects switch over to the kustom head that has an effects processor on it. So one Head driving both cabs at the same time, only one head at a time.

The stacks I have are:

Marshall 1987xl 1960bx Kustom 100HD kustom 4x12 cab

anything else that you need to know just ask and I'll try and provide the info.

Thanks

Answer 1

WARNING: Do NOT plug both heads into the same cabinet as it can do serious damage to the heads.

The trick of re-wring the cab so that you have two independent sets of two speakers will work fine. However I would recommend doing the left column and right column and not the bottom or top row. The bottom row sits very low so as a player you will not get any high frequencies. It will sound very dull to your ears (but it's screaming at your ankles), while your audience is probably already writhing in pain. Even the top row is actually not high enough unless you get at least 6' away from your cab.

If you chose to do this, you need to analyze the wiring for impedance. If your cab is rated 4 Ohms than you either have 4x16 Ohm drivers in parallel or 4x4 Ohm drivers in a serial/parallel configuration. If it's the first: wire the two speakers in parallel. If it's the second, wire the two speakers in series. In either case you will get 8 Ohm impedance (which is fine). If you get this wrong, you'll either end up with 32 Ohms (very low sensitivity) or 2 Ohms (likely to damage the head), so some care is advised.

There is a device that will actually do all the required switching for you (including multiple heads and/or cabs). See http://www.soundsculpture.com/products/headtrip.htm

Answer 2

This can be straightforward, the one caveat its that you can't wire both heads to the same speakers in a cab.

So what you could do is wire one head to 2 speakers in a cab, and have the other head wired to the other two speakers.

It isn't ideal though- it's usually better to keep them apart. Is there a reason you want to do this?

Answer 3

I use sort of the same set up live. I use an ABY box, 1 output goes to my marshall JCM900 head into a 1960 JCM800 - 4x12 cabinet, wired for 16ohms, most marshall heads are able to switch between 4,8, & 16 ohms. The other output goes to a marshall MA100 head into a peavy 4x12 cabinet at 8 ohms. The JCM900 is my lead or overdrive channel, the MA100 is my clean channel. I prefer to use 1 cabinet per head, but that's my preference. The main thing I always make sure happens is that the cabinets match the heads ohms. Ive tried two 4x12 cabs @ 8ohms each setting the jcm900 @ 4ohms. wasn't much louder or didn't seem louder. I'd go with one cab for each head but that's just me. Good luck.