design help

[stool]

I am wanting to build a bass reflex cabinet. I am using and trying to understand Speaker box lite. The driver specs are: Fs=41, Re=5.1, Sd=880 sqcm, Qms=5.9, Qes=.39, Qts=.36, Vas=154.82, Mms=106.73, Bl=19.09, Xmax=5.5, Le=1.46, Hvc19, Hag=8, Cms=178.56. What I came up with is a 81 liter box, which is about what I was looking for. A box Q-value of 7.9, not certain about this, can someone explain. Four ports with 3.8cm diameter and lengt of 1.9cm which would be the thickness of the baffle board. The resonant frequency is 40.5Hz with a -3db at 52.05Hz. The free airspace SPL at 1m rolls up and then flattens out a little above 100Hz. Would it be better if it started flat, then rolled up and then flatten out again? Any and all info will be greatly appreciated.

[sreten]

Looks about right, though I like the look of 120L tuned to 34Hz.

For your 80L/40Hz box you need an ~ 100mm diameter x 110mm length port.

Trying to use the baffle width as a port length won't work well.

sreten.

[stool]

Thank you for the port/baffle comment and the other as well. As far as box Q-level, any particular range best. The speaker mentioned is the P.Audio P150/2226, I was trying to decide upon that or the B&C 15 PS40. Anybody familiar with these or the 12" equivalent P.Audio P120/130LF or the B&C 12 PS32 or PZ32 willing to comment. I was not wanting to get into brands, but this is something that probably should be asked. I would like to keep this at 100 liters max, but not mandatory. Thank you.