Does any one know how much increase in SPL there is by using a same type of speaker cabinett (ex. 2 x 10") by adding a second equal kabinett and place it nexto the other ? I have heard 6 db around 50 Hz. Also any one knows how much deeper i goes. ? lets say 2 systems with one 10" x 2 and 100 W vs another with four 10" X 2 and 100 w ? I do remeber when i used to play guitar , i could easy hear that a half stack with marshall did not have the same low end sound as a full or double stack.