Hi guys,

I have a Laney cub12r combo that I would like to hook up to a 1x12 cab BUT keeping the internal speaker of the combo connected. So i'll effectively have 2x 1x12 speakers. The combo has an external speaker out (8/16 ohm), will be loaded with a 16 ohm speaker, as will the cab. So wiring in parallel will get me 8 ohms, fine for the external speaker out. What I am proposing is this...

Wire combo speaker to a male 1/4. This can be put direct into the external out of the combo amp if just using as a combo. I can't use the internal amp for this, the internal speaker out is only 8 ohm.

Install new external out on combo, wiring to existing external out, + to +, - to -.

Plug combo speaker into external out, 1x12 cab into the new external out, hopefully resulting in the amp driving two speakers at the same time, in parallel.

Is this do-able?

Many thanks for your help,

Something doesnt sound right with that set up. Does the amp play both the internal speaker and the ext cab when the ext cab is plugged in or does the combo's speaker shut off when you plug an ext cab in?
It sounds like the amp can handle an 8ohm load. So you could wire 2 16 ohm speakers in parallel( in a 212 ext cab) and plug that 8ohm load into your ext out. Using the internal speaker would be tricky because once you wire that internal speaker to another speaker the ohms would change and mess with your amp. Even if the combined empedance of those speakers is ideal for your amp, when seperated the internal speaker will be unideal. You might want to see what the impedance of the internal speaker really is first. If it is 16 and your amp can handle 8 then you might be ok. If it is already 8 then adding another 8ohm speaker in parallel will make it 4 and be bad news. I cant say too much for sure because i dont know much about tube amps, only solid state. After all that. If your internal speaker is 16ohms and your amp can handle 8 you could add another 16ohm speaker like you say to the internal output with a switch. Something tells me if it was that easy the amp would have come with an ext cab output that plays both speakers.
Last edited by geo-rage at Nov 22, 2016,