Goldwood 12" Vented box question

[ostripper]

The driver is the goldwood delmar series 12" 8R driver here ... Goldwood GW-12PC-8 12" Heavy Duty Woofer 8 Ohm | Parts-Express.com

I used bassbox pro 6 , used the TS params from GOLDWOOD as the parts- express parameters are freakin' wrong (Qms - Vas was way off).

This excellent driver from goldwood is very HD , with a cast frame but 1/2 the price of a dayton. The params are :

Fs = 32hz
Qms = 3.83
Qes =.56
Qts = .49
Vas = 85L (2.9sq.ft.)

I let BB6 pro do the calculations for a 100L ported enclosure with a 76mm port size , output (below 1). My question is about box size ... bassbox says the driver can be used for either sealed or ported , it suggests a rather large 130L box witch gives a f3 of 26hz. I reduced Vb to 100L and even 85L and my f3 rises to 35-38hz. Is this the only tradeoff ?? Reduced Vb just raises the F3 ?? Are there any other drawbacks with the smaller box. Bassbox shows very little change with the impedance peaks or other "peaking" (Qtc must still be near .707) , just the rise in f3.
Also , can I change the tuning of Fb to compensate for a smaller box ??
Any help for a newbie would be appreciated , I don't want to build the boxes twice.

PS. Attachment below is with the 100L alignment.
OS

[ostripper]

Bump... no answers..

[MJL21193]

A good rule of thumb when looking at drivers for vented box is that the Qts should be below .45. Above that and the driver is more suitable for sealed.
As for the results that Bassbox is giving you, there would be a peaked response when you reduce the box size. You ideally want flat response.