I have a small cab which is actually the bottom part of an older Acoustic combo amp. It is 2 cu.ft. internal and presently loaded with JBL K-140. It sounds okay but obviously a little shy of deep bass. I'm thinking of porting it in the rear as there is no place on the front (it's just large enough to accomadate the 15" spkr.) My thoughts are to buy a ready made port tube from one of the supply houses but curious what size to get and what results to expect. I'm not expecting it to be a large venue cab but something portable for small clubs and such. Any advice??...Bill??