Trying to port it will not work. Then you will have a poorly sounding sub, when you could have a really good one.
When I did car audio, one of the sales guys had a customer whose system had been stolen from his Pontiac GTA (the upper level Trans Am), which had a big glass hatchback window and a storage well below it. Sold the guy a pair of Infinity Kappa subs and a bunch of other stuff and as soon as we (installation department) saw the woofers, we knew it was going to be a big challenge because they like a larger box but that car just doesn't have room for one, so I looked at doing a bandpass box. TermPro showed that it would work, so I came up with a box shape, started on the rest of the installation and did the sub last. The door panels were some kind of formed material, so putting speakers in that would have been difficult & expensive, so it was decided that they would be omitted. That left the system with one pair of 4"x6" two-way dash speakers, a pair of 6"x9" mid-bass separates in the rear 6"x9" pillar location, a head unit, Alpine parametric EQ, the subs and a couple of amplifiers. Looks like a recipe for disaster, right?
The day I finished was the start of a car audio sound-off and when I was ready to set up the levels & EQ, I found that the RTA was already outside, so the shop manager & I did it by ear. The front 'stage' was amazing, the sound blended very nicely from front to rear- there was no apparent shift as the frequencies moved up and down the scale and the low end was strong and very smooth.
The customer had brought the car in because he wanted to enter the contest, so it was moved out to the staging area and as we judged the cars (if we worked on something, we were exempt from judging it), I could see that something didn't look right, by the car owner's actions. As it went through the line, he scored well on appearance, wiring layout & integrity, RTA/noise and sound quality. When it was done, I sat in the car to listen and with the selected music, I was very happy with the sound- I had installed it, but I can still be pretty impartial- if it doesn't sound right, I don't feel bad, I just want to fix it. I looked at the RTA results- it scored 37/40 points and I don't think I had ever seen a higher score, although I have heard of some that came in at 40/40 points.
The guy took his score sheets and trophy, went to the MTX booth to buy a bass disc and drove to a far corner of the lot, where he proceeded to blast the system so loudly that he destroyed the woofers because he hated the sound so much. The problem- his old system had a pair of Orion 10" woofers in a simple carpeted panel fastened to the storage bin and the seal was terrible, so it leaked and the sound was complete mud, but that's what he was accustomed to and it's what he had come to like. Since there was nothing to compare it to, I could only give him what I would consider a normal result- clean, tight, extended bass that blended well with the rest of the sound.
