Hello, I have installed an Eton EC-12/800 in my Audi in the original case. I wanted to expand now and add two EC-12/1000. I would like to have these in a double case. Since Eton unfortunately cannot offer me something like this, I have to make a case myself. I still have a double case, but the volume does not fit. Now my question: What happens if my case volume is too large/to small?? THX