2 heads, one cab

B

BloodRose

Professional Scapegoat
Question. I’ve never done this before, so wanna make sure I’m ok..
I brought my PV ultra plus Home. Normally I use my Carvin 4x12 for that head. No room for the cab so making due. Ok, my spawn 4x12 has 2 inputs ( I think all my cabs do) one of them on the splawn has the Neutric locking jack, the other does not. I left my spawn head plugged into that jack and plugged my PV head into the other jack. Is it ok to plug 2 heads into one cab? Assume so as they put two jacks on it. Next, the cab is rated 16 ohms.. set both heads at 16 ohms?? Lastly, can one actually PLAY both heads thru same amp at same time??
 
Re: 2 heads, one cab

If it's a stereo 4x12 you can run it with 2 amps driving 2x12's each. Just make sure the selector switch is set correctly. A 16ohm cab would indicate that it's 4 16 ohm speakers wired series/parallel. So for stereo operation you'd want the amps set to 8 ohms. Yes you can run two amps at the same time...the stereo cab is effectively two 2x12's in one box. But NEVER and run two amps into the same set of speakers...that would be bad.
 
Re: 2 heads, one cab

PFDarkside said:
No, it’s not a stereo cab. Do not connect both heads. You will damage both heads.
Click to expand...

Yeah, if it isn’t stereo the results won’t be pretty! I suppose you could wire the cabinet up as 2 separate 2x12 cabs in one box??? I have a buddy who does something similar with a 2x12. It is actually wired up as two separate 8 ohm 1x12’s so it can have two smaller recording heads running through the one mic’d cabinet in his isolation booth. I mean he seems to enjoy the results so I don’t see why this couldn’t be scaled up to a 4X12 situation?
 
Re: 2 heads, one cab

Yes, it can be rewired to stereo, allowing two heads to be used. As is it’s a parallel pass through for additional cabs.
 
Re: 2 heads, one cab

Empty Pockets said:
Just spend the 30 seconds it takes to unplug one head then plug the other one in.
Click to expand...

prolly would/should just do this as the other posts are confusing me. First of all for clarification. Im Not playing thru both heads into same cab at same time.... I just have both heads plugged in (on head into each input) to same cab. cab is 16 ohm and I have both heads set on 16 ohm. I guess for safety sake, Ill either plug one or the other, or plug the PV into my Avatar 2x12. I surely dont want to fork something up. Just trying to figure why the cab has two inputs then....??
 
Re: 2 heads, one cab

You’d be trying to force speaker level back through the other amp’s output transformer. If you didn’t damage anything you’d at least have a really odd load on the active amp (which could then damage something)

As stated above, the second jack can be used either for a choice of nuitrik or standard jack or to add an additional cab in parallel if your amp has only one output. (If you’ve got one 4 ohm, one 8 ohm and one 16 ohm output, you can go from the 8 ohm output to the 16 ohm cab jack, from the second cab jack to the next 16 ohm cab)

By the way if I’m using multiple heads on one cab, I only run one IEC cable to that area. That way I have to swap both power and speaker cables when I switch heads. There’s no risk of powering up the disconnected head without a load.
 
Re: 2 heads, one cab

BloodRose said:
prolly would/should just do this as the other posts are confusing me.
Click to expand...

Not probably, definitely. Best way I can put it is, if the jacks are wired together, the amp that is on sees the other amp's output transformer as another cab, just turning an amp off doesn't disconnect it. The amp that is off is getting an electrical enema and that makes the transformers very angry, and they often don't get over it.
 
Re: 2 heads, one cab

BloodRose said:
prolly would/should just do this as the other posts are confusing me. First of all for clarification. Im Not playing thru both heads into same cab at same time.... I just have both heads plugged in (on head into each input) to same cab. cab is 16 ohm and I have both heads set on 16 ohm. I guess for safety sake, Ill either plug one or the other, or plug the PV into my Avatar 2x12. I surely dont want to fork something up. Just trying to figure why the cab has two inputs then....??
Click to expand...

Most 4x12s I've owned have two inputs so you can stack them. I have two 16ohm 4x12s and each has two parallel inputs. That means I can plug one head into the first cab, then plug that first cab into the second one to provide an 8ohm total load.

Your situation is probably not hurting anything, but I wouldn't risk it. Just unplug the one you're done with and switch to the other one.

ProTip: most Marshall 4x12s from the last few years can be run in mono at 16ohms or stereo at 8ohms per side. Maybe grab one of those if you want an affordable yet quality 4x12 that can handle two heads at once.
 
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Re: 2 heads, one cab

devastone said:
Not probably, definitely. Best way I can put it is, if the jacks are wired together, the amp that is on sees the other amp's output transformer as another cab, just turning an amp off doesn't disconnect it. The amp that is off is getting an electrical enema and that makes the transformers very angry, and they often don't get over it.
Click to expand...
It tends to let the smoke out of the wire.

Sent from my Alcatel_5044C using Tapatalk
 
Re: 2 heads, one cab

Never let the smoke out. Smoke makes everything electric work. If it leeks out...bad bad bad bad.
 
Re: 2 heads, one cab

Crap! I dunno why I didn’t even think of the other jack being for out purposes only. I assume the neutric jack is for the amp in. And the other is out to another cab.
Now I’m worried that I may have damaged something.. I had the spawn head into the neutric jack, but never turned it on. The PV head was into the other and was playing that head. ( could be why it was noisier than I remember..??)

I’ll def run only one going forward!! I just hope I didn’t damage anything!! I played for prolly an hour..
Thanks so much for the info!!

Prolly be a day or so before I can check the splawn head. I’m pretty scared to now though.
Is this something I’ll know right away if I jacked it up??
 
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Re: 2 heads, one cab

It's not an "out" only, the 2 jacks are just wired in parallel so both jacks so you can use either, or yes, you can use one to hook up another cab which will put the cabs in parallel.
 
Re: 2 heads, one cab

Ok, I got the chance to hook up one head then the other. One at a time...!!!!!! Both seem to be working ok (Thank GOODNESS!!!) I definately learned something and wont do this again. Plus, the PV was making a bad hum when both were hooked up, and isnt doing it being hooked up alone.

As far as damage. Is this something that probably would have manifested itself while both hooked up, or is this something that may show up down the road? I had only the PV on while they were hooked up that way and played for maybe an hour or two and didnt have it cranked to the gills or anything. (if that makes any difference)

Thank you all again for the valuable input!! Hopefully, you saved me a heartache!
 
Re: 2 heads, one cab

I have another one! Just cant fit it in the room right now. haha But, I do have an Avatar 2x12 here, so will hook the PV up to that one. Just need to find out what Ohms rating it is so I can set the amp properly.
 
Re: 2 heads, one cab

BloodRose said:
prolly would/should just do this as the other posts are confusing me. First of all for clarification. Im Not playing thru both heads into same cab at same time.... I just have both heads plugged in (on head into each input) to same cab. cab is 16 ohm and I have both heads set on 16 ohm. I guess for safety sake, Ill either plug one or the other, or plug the PV into my Avatar 2x12. I surely dont want to fork something up. Just trying to figure why the cab has two inputs then....??
Click to expand...
Google your cab. If it's a stereo cab all systems go. Mono means no.

Sent from my LGMS330 using Tapatalk
 
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