I have slowly gray hair, just tried with winisd alpha to calculate a housing for the axx1010. the tsp I took original from raveland and to the devil I just can’t get on the proposed 20 liter model with the same tuning. I wanted to compare the woofer for the test in winisd with my woofer, but on the basis I don’t get a valid result. what am I doing wrong? does someone have a idea? what do I have to do with the waltz if I have a hair use type goes? I have chosen the following: the woofer->number of drivers and normal (no isobarik)->vented->c4/cs4 (sub-)chebyshev. I now give the information (20liter,port 7×15) according to raveland I come to the following result: tuningfrq:52 hz and spl at 50 hz with approx. 87 db raveland does not indicate the tufrq but according to which information the woofer has at 50hz approx. 90 db? as I see the tuning sucks because then he can not deeply. and can tell me what the information: qb3 qua si-butterworth bb4/sbb4 (super) boom-box 4/cs4 (sub-)chebyshev ebs3 extended bassshelf -3db ebs6 extended bassshelf -6db mean? sry for the many text but I hope someone can help