Help with Randall R412C MTS speaker cab wiring

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k9blek

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I just loaded a Randall 412CBP cab up with speakers and I can't seem to find a good diagram for how to wire it back up. I unloaded it about 2 years ago so I forgot ! I have four 8 ohm speakers in it. It has the plate on the back that you can run 4 OHM mono, 16 OHM mono, or 8 ohm each jack stereo. It has the stereo / mono switch. Any help would be appreciated. thanks !
 
I would assume that your cab came with 16 Ohm speakers originally and as far as I know you can't get 4 X 8 Ohm speakers to work like the rear plate says (4/16mono) If having a stereo cab doesn't matter then I'd just wire it up minus the switch and second I jack like this -

https://wgsusa.com/how-properly-wire-4x12-speaker-cabinet
 
Well that might explain why I can't find a schematic that works. ****! I went out of my way to get 8ohm speakers for nothing!
 
Here you can see how the switch in your cab works:
Speaker_Cab_Wiring.jpg

If you use 8 ohm speakers instead of 16 ohm, you would switch between 2 and 8 ohm mono and each stereo side would have 4 ohm.

Alternatively you could wire the two sides of the speaker pairs in series to get 16 ohm stereo on each side and switch between 8 ohm and 32 ohm mono.

Hope this helps.
 
galao said:
Here you can see how the switch in your cab works:
Speaker_Cab_Wiring.jpg

If you use 8 ohm speakers instead of 16 ohm, you would switch between 2 and 8 ohm mono and each stereo side would have 4 ohm.

Alternatively you could wire the two sides of the speaker pairs in series to get 16 ohm stereo on each side and switch between 8 ohm and 32 ohm mono.

Hope this helps.

It does help a little thanks. So what would be your suggestion? This kid really doesn't know much (less than me). Would I just cover up the 32 ohm hole to make sure it wasn't used? He said he doesn't mind wiring it a different way as long as it works.
 
Yeah I'd buy it only postage to Australia on such a thing would require me to sell an organ or two.
 
Well, this is not the organ trade forum. I would rather suggest to find a technical solution to get the cab running. :wink:

As mentioned above both versions would have one mono jack with 8 ohm which can be used with any average amp. I would wire the two speaker pairs in series to get 16 ohm stereo, which can also be used with any stereo power amp.

If you have access to a label maker, just label both jacks "16 ohm stereo" and the one on the right hand side "8 ohm mono". The other jack should not be used with a mono amp as 2 or 32 ohm are not really usefull. The pannel should look like this one:

marshall-1922-43745.jpg
 
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