# Custom 2x12 Cab Wiring (mono/stereo, no switch) *NEW VIDEO INCLUDED



## jbealsmusic (Feb 12, 2014)

*Custom 2x12 Cab Wiring (mono/stereo, no switch)*

_*2020-10-29 UPDATE: I was forced to make another one of these, so I filmed the process. Here's the video*_





I'm building a 2x12 cab for a buddy of mine who requested a special wiring setup _(no, I don't build custom cabs for customers, so please don't ask.)_

Apparently he has blown amplifiers in the past by having them plugged into the wrong mono jack or by putting the switch in the wrong position, causing an impedance mismatch between the amp and cab. He wanted a "dummy proof" (his words) jack plate that has both mono and stereo options.

This is what I came up with:








The concept is simple, use one jack when you want mono (doesn't matter which one) or use both jacks simultaneously when you want stereo. It gives you the following connection options:

Jack 1 (when used alone): Mono, 8-ohm load, both speakers are in parallel
Jack 2 (when used alone): Mono, 8-ohm load, both speakers are in parallel
Jack 1+2 (when used simultaneously): Stereo, 16 ohms per jack, each jack only connects to one speaker
I thought it was cool, so I figured I'd share it here. Since it works for a 2x12, it stands to reason that it works on any 2X speaker cab (2x8, 2x10, etc.) It also easily translates to 4X speaker cabs. The fully wired jack plate will cost you less than $25 in parts (less than $10 if you use the cheap plastic cliff-style jacks). That's half (or less) of what it would cost you to buy a pre-made mono/stereo jack plate, so that's always good.

Try it on your next cab project. The only thing missing compared to the standard mono/stereo jack plates is a 4 ohms option. Meh, who needs it.


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## Frenchy99 (Oct 15, 2016)

I can't see the attached picture!


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## jbealsmusic (Feb 12, 2014)

Frenchy99 said:


> I can't see the attached picture!


Now?


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## Frenchy99 (Oct 15, 2016)

Thanks!


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## troyhead (May 23, 2014)

@jbealsmusic This one isn't quite as "dummy proof" but is an awesome mono/stereo option. If you covered up the bottom jack and pretended that didn't exist, then I think it works the same as what you are describing. I could be wrong, maybe the "right" jack doesn't run both speakers. There is a schematic on the site if you want to see how they wired it up.

Jack Plate - Plug and Play, Mono/Stereo | Amplified Parts


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## jbealsmusic (Feb 12, 2014)

troyhead said:


> If you covered up the bottom jack and pretended that didn't exist, then I think it works the same as what you are describing. I could be wrong, maybe the "right" jack doesn't run both speakers.


The right jack does not run both speakers. Next Gen used to sell those, but discontinued carrying them a while back. They didn't sell much since most people just make their own jack plates, which is generally way cheaper anyways.

I actually prototyped a custom jack with Switchcraft a few years ago (before Next Gen) that I developed to make a 2 jack version of that plate, which I thought was much better and more intuitive. Using 8-ohm speakers, it would have provided the following options:
Jack 1 = 4-ohm load (mono; speakers in parallel)
Jack 2 = 16-ohm load (mono; speakers in series)
Jacks 1+2 Simultaneously = 8 ohms per jack (each individual speaker)

Cooler and better as it was to me, there's no indication that the market would even want something like that. When I started Next Gen, I thought I would revisit the idea again. But we could barely move any of the pre-wired jack plates we tried to carry, so investing a ton into producing our own version was out of the question. Parts distribution only for now.


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## jbealsmusic (Feb 12, 2014)

Sorry to resurrect this old thread. I thought it would be better than making a second thread on the same topic. I was essentially begged to do this again, so I used the opportunity to film the process and make a video. Thought some people might enjoy it, or find it useful in some way.






Carry on!


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## jb welder (Sep 14, 2010)

jbealsmusic said:


> Sorry to resurrect this old thread. I thought it would be better than making a second thread on the same topic. I was essentially begged to do this again, so I used the opportunity to film the process and make a video. Thought some people might enjoy it, or find it useful in some way.


Hi Jon. I was going to nitpick a bit in a PM, but you seem to have them turned off (totally understandable) so I'll have to do it here. 
The Cliff jack diagram on your website (and in vid) has an error:










Also, for the other drawing (sw-craft), the convention is that the tip is drawn furthest from the sleeve, but no biggie.

Failure analysis: I like your setup as even if a jack switch gets dirty/oxidized, you still maintain at least a one speaker load. And the now mismatched impedance will decrease the power going to that speaker.
For someone who uses the cab primarily mono, I would advise them to alternate between the input jacks, and not always use the same one. That bit of 'exercise' for both jacks will keep the jack switch contacts from oxidizing.


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## jbealsmusic (Feb 12, 2014)

jb welder said:


> Hi Jon. I was going to nitpick a bit in a PM, but you seem to have them turned off (totally understandable) so I'll have to do it here.
> The Cliff jack diagram on your website (and in vid) has an error:
> 
> View attachment 334168


Aw crap... That's what I get for trying to rush it. Thanks for pointing it out!



> Failure analysis: I like your setup as even if a jack switch gets dirty/oxidized, you still maintain at least a one speaker load. And the now mismatched impedance will decrease the power going to that speaker.
> For someone who uses the cab primarily mono, I would advise them to alternate between the input jacks, and not always use the same one. That bit of 'exercise' for both jacks will keep the jack switch contacts from oxidizing.


Great advice!!

_*EDIT: Pic corrected in the article, and video edited to remove the pic._


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