I have a 212 vertical recto cabinet which sounds fantastic. My drummer says he's having a hard time hearing my guitar when my speaker cabinet is pointed at me at the front of the stage. When I turn my volume up to compensate, everyone else gets louder and the drummer still can't hear me. If I turn my amp towards him, he can hear me just fine, But I can't. I don't have the funds for second Mesa cabinet just now, but the drummer came up with an old 8 ohm 150w sun cabinet with a 15 inch speaker and a horn. Can I safely plug this into another speaker jack on the back of my amp and use it simultaneously with my 212 vertical recto?