Moin, I am currently building a housing for 2 pieces Mivoc 8″ chassis, only the reflex tube is missing and I would need help with the calculation https://www.mivoc.com/gs/media/products/11802000_AW2000-Datenblatt.pdf The housing has an internal volume of 27,5l. Should I install one or two pipes, how large must the diameter be at least, how much distance to the rear wall must be available? Problem is possibly the low depth of the housing (bottom 23cm, top 12cm), I can also build a housing for 2 pieces Mivoc 8″ chassis. Take an angled pipe? Greetings