can you port a 6x9 and gain some high end response, say like 70 hz and up? or will it sound like poo? I have a sub that is tuned real low and i was wondering if my high low's to my low high's would be improved, if you can understand that.
Highly doubtful. 6x9s are designed for infinite baffle use (package trays), and would give near horrible performance ported. I'm sure there are some exceptions, but 6x9s are pretty much a niche product. You won't see them anywhere but in the rear of a car.