6th order bandpass

[Chris8sirhC]

I have been going through every possible option to try to use up these 16 10's that I have lying around (TL, dipole, Lin transform, etc). I came up with a 6th order bandpass that looks good from 50hz to 130hz or so. I am looking to cover from 50hz up to 150hz if possible. I also want it to be as small as possible. Here are the paramaters:
Re 7.20 [ê ]
Fs 44.26 [Hz]
F1 35.48 [Hz]
F2 56.23 [Hz]
Zm 53.74 [ê]
D 208.00 [mm]
Qms 5.80
Qes 0.90
Qts 0.78
Bl 6.76 [N/A]
L1K 1.47 [mH]
L10K 0.72 [mH]
Ms 20.47 [g]
Vas 101.85 [l]
dBSpl 92.34 [dB]
Cms 0.63 [mm/N]
Ma 48.00 [g]
FsMa 24.20 [Hz]

The box i came up with in WinISD is as follows (2 drivers in a clamshell IsoBaric):
rear volume 1.541 ft^3
rear freq 41.54hz
rear port length 3.73in dia= 2.68in

front volume 0.925 cubic feet
front freq 93.72
front port length 1.25in dia = 4.02 inches

at max power (60 watts) I am getting about 112db
I have never made this type of design before. Anybody that has experience with bandpass, what do you think of this design. Could I make it smaller and still cover down to 50hz? I plan on using at least 4 of them in a room ala gedlee, but I will be able to build up to 8 of these things.

[Chris8sirhC]

Is the group delay always 2-3x worse than a lin transform design?