Driver : Beyond Audio 15" Inhuman

Number of drivers : 1
Box type : Vented
Box size : 155.7 l
Tuning frequency : 45.00 Hz
Vent : 1 vent(s)
25.90 in length for each
14.00 x 10.50 in rectangle
Relative
Freq Gain SPL
[Hz] [dB] [dB] 20.00 -26.13 94.63
25.00 -17.77 102.99
30.00 -10.40 110.36
35.00 -3.22 117.54
40.00 4.83 125.59
45.00 12.34 133.10
50.00 9.23 130.00
55.00 6.21 126.97
60.00 4.51 125.27
65.00 3.46 124.22
70.00 2.76 123.53
75.00 2.27 123.03
80.00 1.91 122.67
85.00 1.63 122.39
90.00 1.42 122.18
95.00 1.24 122.00
100.00 1.10 121.86

Also, If i want 5 cubes for the sub, do i subtract the port volume from the box volume to get the air for the sub?

thanks for any help

Yes you want to get your net volume inside your box. Meaning you subbtract your port volume, sub displacement, any braces or angles inside the box.