Hello community, I have now built a box for my GZNW 15. This one has the shape of a cube and an inside volume of 54L. So the problem now lies in that the bass sounds like a beating sheet. We then roofed me cut a hole in… Said we have cut in the side a 100mm hole. The level has become better and more acidic… But now ask me a couple. My thought was to make 2 100mm holes next to each other and d a then use 2 77mm long reflex tubes. What happens then? And of the wide I am a little disappointed the 2.5kW the car (Audi 80 Cabrio) does not bring. Please help me…. What did I do wrong or how can I change it? Greeting Hermann