Good day everyone !! I just have a couple questions about this method. I want to connect my 2x12 Spider III 150 amp to a 4x12 cab (Line 6, as well) but I'm not sure if I must disconnect the 2x12 speakers in the combo to use the 4x12 cab, or does the amp automatically cancel the 2x12 output when the two cables are plugged in to the cab ? I will thank every single comment Thanks and have a nice day.