This may be a dumb question, but the speaker outlet jacks on the DSL20 head are confusing as to where to plug in your speaker cabinet. The one on the left is labeled 1x16 ohms and is self evident. The 2nd and 3rd jack are confusing. Does the 1x8 ohm speaker cable go in the middle jack and the 2x16 ohm cable into the right jack? There is no designation telling which jack to use. Sorry this is so incoherent, but I can't seem to post a photo of the back of the head.