# cab wiring



## ezcomes (Jul 28, 2008)

just bought an Orange 2x12OB...its 16ohm...

i want to wire it so that one jack is 4ohm mono...and the other is 16ohm mono...how do i do this? do i need a switch, or is there a way i can just do it with Jacks?


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## greco (Jul 15, 2007)

Is the cab 2 x 12" speakers with each speaker rated at 8 ohms? 

I assume the answer will be "Yes"

You could wire one jack with the 2 speakers wired in parallel to get 4 ohms 

You could wire the other jack with the 2 speakers wired in series to get 16 ohms

Cheers

Dave


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## GTmaker (Apr 24, 2006)

greco said:


> Is the cab 2 x 12" speakers with each speaker rated at 8 ohms?
> 
> I assume the answer will be "Yes"
> 
> ...


I just did a quick diagram and if you wire things up as Dave sugested, there will be a connection between the 2 positive terminals of the speakers that will need to be severed during the 4 ohm mode. You can do this with an ON/OFF switch that would be OFF (no connection) during the Series mode and can be switched ON during the Parallel mode.
thats my understanding untill someone much brighter then me can prove me wrong again.
Me being wrong is OK as I tend to do it on a regular basis.

G.


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## greco (Jul 15, 2007)

I was hasty with my response and didn't do a diagram. GTmaker could be correct here. I'll spend some more time on this and post tomorrow. Hopefully, others will respond to help out.

Cheers

Dave


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## greco (Jul 15, 2007)

This is what I had in mind...minus the stereo "option"

CABINET WIRING - MONO/STEREO This schematic shows the wiring of a Marshall® 2x12" speaker cab with a Mono/Stereo switch and two input jacks. With the Mono/Stereo switch set to Mono, *you get the two 8-ohm speakers either in series (16 ohms) or in parallel (4 ohms) depending on which input jack you use. * With the switch set to Stereo, each jack connects to its own 8-ohm speaker. In this mode, the cabinet can be used with a stereo power amp and separate left and right signals. 









*******************************************************************

THESE ARE THE STANDARD WIRING DIAGRAMS...easier to follow.










I am still on my first coffee...maybe I'm still missing the point that GTmaker is making.

Cheers

Dave


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## GTmaker (Apr 24, 2006)

greco said:


> This is what I had in mind...minus the stereo "option"
> 
> CABINET WIRING - MONO/STEREO This schematic shows the wiring of a Marshall® 2x12" speaker cab with a Mono/Stereo switch and two input jacks. With the Mono/Stereo switch set to Mono, *you get the two 8-ohm speakers either in series (16 ohms) or in parallel (4 ohms) depending on which input jack you use. * With the switch set to Stereo, each jack connects to its own 8-ohm speaker. In this mode, the cabinet can be used with a stereo power amp and separate left and right signals.
> 
> ...


HEy Dave....thats for the graphics...makes it easier to explain...

In the PArallel version, there is a connection betweek the + on one speaker and the + ternimal of the other speaker.
This connection does not exist in the Series setup.

Thats all I was trying to point out. If this connection is taken into account with your other schematic then all is good.

G.


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## ezcomes (Jul 28, 2008)

i did find that diagram with the switch last night...it seems like kind of a PITA...so maybe i'll just keep it 4ohm mono...i kind of figured i'd need a switch, but hoped i could get away with just the jacks...

i guess the good thing about doing the parallel mono is that if one speaker 'should' crap out on me...i'd still have the other speaker to finish a set with...


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## greco (Jul 15, 2007)

ezcomes said:


> but hoped i could get away with just the jacks...


You can get away with just the 2 jacks....one for series and one for parallel. 
If one speaker craps out, just move the plug to the parallel jack.

Cheers

Dave


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## jb welder (Sep 14, 2010)

Yes you can do it with just the switching jacks as greco's first diagram shows. You will need stereo jacks with switches on the tip and ring terminals. Here is a revision without the stereo/mono switch:
View attachment 3667

But I would recommend against this method (especially for tube amps) as you may be running a lot of power through the jack switches and there is potential for failure. With a tube amp running the cab in 16ohm mode, a failed jack switch will mean a no-load condition which could damage the amp's output transformer.
So I would recommend wiring it either 4 or 16 ohms as shown in greco's "standard wiring" diagrams, or if you really need the flexibility, make it switchable using a high current switch (such as a toggle) rather than switching jacks.


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## greco (Jul 15, 2007)

jb welder said:


> Yes you can do it with just the switching jacks as greco's first diagram shows. You will need stereo jacks with switches on the tip and ring terminals.
> But I would recommend against this method (especially for tube amps) as you may be running a lot of power through the jack switches and there is potential for failure. With a tube amp running the cab in 16ohm mode, a failed jack switch will mean a no-load condition which could damage the amp's output transformer.
> So I would recommend wiring it either 4 or 16 ohms as shown in greco's "standard wiring" diagrams, or if you really need the flexibility, make it switchable using a high current switch (such as a toggle) rather than switching jacks.


Could you not just use 2 standard TS jacks and wire one for 8 ohms (parallel) and the for 16 ohms (series)? Each speaker (typically) has 4 connector spades....2 for +ve and 2 for -ve...so the connections at the speaker are not an issue...Correct? 

Why the need for stereo jacks?

Cheers

Dave


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## jb welder (Sep 14, 2010)

I think you are asking if the 2 speakers can be wired in series and parallel at the same time. That is not possible.
The switching jacks are required because the parallel connections must be disconnected when the speakers are put in series.
Stereo switching jacs are required because 3 switches are needed as shown in the first diagram.
For fun, draw out your 2 "standard wiring" diagrams on a single pair of speakers with 2 jacks. Then you will see what I mean about the speakers not being able to be in series and parallel at the same time.


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## greco (Jul 15, 2007)

jb welder said:


> For fun, draw out your 2 "standard wiring" diagrams on a single pair of speakers with 2 jacks. Then you will see what I mean about the speakers not being able to be in series and parallel at the same time.


WOW...Do I ever feel stupid!!...LOL 
(it happens reasonably often, so I should be getting used to it by now!)

However, I did learn something..and that is the main thing.

Thanks jb welder and GTmaker.

Cheers

Dave


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## jb welder (Sep 14, 2010)

Well, you shouldn't feel stupid for that, but if that's the price of knowledge then I'll take the stupid feeling every time .

Here's the diagram with a single jack and a toggle switch:
View attachment 3672


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## greco (Jul 15, 2007)

jb welder said:


> Well, you shouldn't feel stupid for that, but if that's the price of knowledge then I'll take the stupid feeling every time .
> 
> Here's the diagram with a single jack and a toggle switch:
> View attachment 3672


Thanks for the diagram. It certainly seems easy and logical when it is seen in diagrammatic form.

Possibly "embarrassed" is a better word than "stupid". 
I thought I had the solution and was determined to convey that to the OP. 

Cheers

Dave


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## ezcomes (Jul 28, 2008)

i had drew out a diagram...but wasn't sure if there is a 'switch' jack or not...I will probably just rewire to 4ohm and be done with it


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