would it be safe to add a port to this custom box.. http://www.sounddomain.com/sku/RTE76110 ? It is 1.2 cub ft, but my 10" sub reccomends 1.3 for ported. would it be safe to add a port? how would it affect the sound? if you think it is not a good idea to add a port, how will it sound to leave it sealed, even though my sub reccomends .75 cub ft for sealed (compared to the 1.2 that the box is). if you thinks it would be ok, how would i install it? i was thinking that it could be placed on the left side. thanks for any advice.