I have a quick question here. I know for the distance from port to any wall, it should be at least at diameter away at minimum. But how about from back of port to back wall? I mean, say if we had an enclosure that was 10" in depth internally. And the port is 6" long. That means theres only 4" from back of port to back of enclosure. Would this be enough? Is there any rule to follow? Thats not the specific numbers that I will be using, but the same question applies. I am wanting to use something like a 6" vent, but very small space from that to back wall, about 2" or 3". Please help if you can!

Thanks!
Adrian