# Guitar Cabinet wiring question



## BBoy (Feb 6, 2010)

Hi, I have bought an empty 2 x 12 guitar cabinet and I want to install some speakers. I would like to wire them up so that I can use either one speaker or both. I realize that this may involve a switch. But I'm not sure how to wire it up regarding the switch or ohms. The amps are 8 ohms some are only 15 watts with a 10" speaker and I want to get a fuller sound.

Any help is appreciated.

Thanks

Bboy


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## greco (Jul 15, 2007)

Hi Bboy...Welcome to the forum. Hope you enjoy your time here.

You say the "amps are 8 ohms"...are you using more than one amp here? 

Is/are the amp/amps using tubes ?

If you have a 2 x 12 cab...why would you only want to use one speaker at a time?

Sorry...I'm confused by what you are trying to do.

What is/are the make(s) and model(s) of your amp(s) for starters...

cheers

Dave


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## Fader (Mar 10, 2009)

Lots of diagrams and info here.

http://www.colomar.com/Shavano/2x12wiring.html


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## BBoy (Feb 6, 2010)

Hi, thanks for repling. There two amps one about 10watts and the the other 30. The 10 is solid state the other tube. I would like this feature as I do not feel the smaller one will be able to drive both speaker and produce a good tone. The speakers are 8ohms each Cannibis Rex.

Thanks

Bboy


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## greco (Jul 15, 2007)

Bboy...I think that either of those amps driving 2 x 12" Cannibis Rex speakers is going to be so huge tonewise that you will need to change your undies after a few minutes of playing through the cab.

My little 5 watt head sounds fantastic through a 2 x 12 cab.

Cheers

Dave


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## BBoy (Feb 6, 2010)

Hi, thanks Dave for the heads-up. I will give that a try. I was concerned that the little amp would not have enough power to drive the speaker properly to get a good sound.

That schmatic page on speaker hook-ups is great. 

Thanks 

Bboy


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## greco (Jul 15, 2007)

Do you know the output impedance of the tube amp? (....or can you choose between 4 or 8 or 16 ohms?)

It would be a good idea to wire the speakers to match the output impedance of the amp (as per the diagrams in the link from Fader).

Cheers

Dave


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## BBoy (Feb 6, 2010)

Hi, thanks for the input. The amps are all 8 ohm and none are switchable.

Thanks

Bboy


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## greco (Jul 15, 2007)

Depending on how you wire your speakers, you will have 4 or 16 ohms total in the cab.

Apparently, SS solid state amps aren't bothered by impedance mismatch and tube amps are OK with 100% mismatch (i.e., your amp would be OK with 4 or 16 ohms as it has 8 ohms out as 8 ohms is 100% "away" from either 4 or 16 ohms). 

I prefer to avoid mismatch...but that is just me. 

Again, it is my understanding that mismatch only becomes a problem if you play at loud volumes for extended periods of time (it shortens the lifespan of the tubes).

Let us know how it sounds once you have tried it. 


Cheers

Dave


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## Granny Gremlin (Jun 3, 2016)

BBoy said:


> Hi, I have bought an empty 2 x 12 guitar cabinet and I want to install some speakers. I would like to wire them up so that I can use either one speaker or both. I realize that this may involve a switch. But I'm not sure how to wire it up regarding the switch or ohms. The amps are 8 ohms some are only 15 watts with a 10" speaker and I want to get a fuller sound.
> 
> Any help is appreciated.
> 
> ...



You can get away with using a switched jack (and a normal jack) vs a jack and a switch - In my experience it is often best to not have a protruding object (switch tip/knob) on the back of a cab. 

A few other people alluded to it already, but the main issue is that the 2 cab settings will de facto be different impedances - e.g. if both speakers are 8 ohm, then single speaker mode will be 8 and dual speaker mode will be either 4 or 16 depending on how you wire it. If your amp's output transformer had at least a second tap then you'd be golden, but since you say they don't (and I am assuming tube amp here) you are in a bit of a pickle. There are a few ways you could deal with this, but they all have drawbacks and therefore nobody gonna recommend them.


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## nonreverb (Sep 19, 2006)

greco said:


> Depending on how you wire your speakers, you will have 4 or 16 ohms total in the cab.
> 
> Apparently, SS solid state amps aren't bothered by impedance mismatch and tube amps are OK with 100% mismatch (i.e., your amp would be OK with 4 or 16 ohms as it has 8 ohms out as 8 ohms is 100% "away" from either 4 or 16 ohms).
> 
> ...


Just to clarify, solid state amps are ok with impedance mismatch that's higher than their rated impedance. There can be trouble if the impedance is significantly lower than spec. especially at high volume.


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## jb welder (Sep 14, 2010)

Just a reminder that this question was posted in 2010.
The scourge they call 'recommended reading' strikes again.


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## nonreverb (Sep 19, 2006)

jb welder said:


> Just a reminder that this question was posted in 2010.
> The scourge they call 'recommended reading' strikes again.


Busted!


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## greco (Jul 15, 2007)

nonreverb said:


> Busted!


Not a wasted effort. I appreciated post #11.


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## Frenchy99 (Oct 15, 2016)

Wow...

Took me 10 years to get it !


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