Any advice on doing an external port, like how to attach it and are there any negatives to doing this? Im planning on getting 2 sa-8's and putting them under the back seat of my 03 extended cab 1500. I will have the port coming out the side of the box under the seat as well. I plan on making it so I can remove the port to exchange with others, really just to see the difference and also because of size restictions. Box will be 2 cubes after sub displacement, so I will probably do a 5"x6" port 32.5 inches long for 33hz tuning and another one fro 38 or 40 hz. Thanks for any input guys.

A removable port? Not sure I've ever seen one, I can't really even picture what you mean.

it's certainly been done before, I'm not sure how to attach and detach it though. Perhaps Jacob will see this and post how he did his for the sa-8 testing

aero's are easier to remove but it looks like your port will be made out of wood.

You will need to either form a lip around the entire port so you can bolt it to the box or you can make a massive port area and change tuning by plugging part of the port.

I do these with different designs but depending on the size and how the box is made, one of the 2 methods usually cant be used due to space, it's either one or the other.

A removable external slot would be difficult. At least I haven't seen a successful one. The best changeable slot ports i've seen have been internal, where a large hole was cut out of one baffle of the box, and port adapters with varying port sizes and lengths were inserted into the box and then fastened over the hole. The hardest part about the external port ordeal is trying to seal the port to the box.

But probably an easier option would be to do a round port. If the port can fit inside the box length-wise, just cut out your 6" diameter hole and use the same size aeroport or whatever, and just interchange differing length ports to change the tuning.

Just a question, do you really think you will hear the difference between a 34 htz tune and a 38 htz tune? Under the rear seat? Are you going for sound quality or sound pressure levels? Whick way you think the subs will be facing?

Honestly probably not. If i do a slot port theres now way im getting it to fit built into the box. I have used aero ports in the past and like them, would one 4 inch be sufficient for 2 cubes? that would be easier to get a good seal with.

2 cubes is leaning towards the large size, in fact .6 is the optimum. Yes 1 full length 4" aero port works perfect.

i love running expernal aeros for my spl/ daily system due to ease of tuning... for your application id say a single 4 would be fine... will probably have some port noise but under the back seat you probably wont hear it.... PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES this is a good calculator for aeros.... looks like if you going for around 34hz with a single 4'' it will be about a foot long... and of corse gets shorter for higher tuning..

slim down the box to 1.8 yields 32 tuning.

slim down the box to 1.8 yields 32 tuning.

Slimming down the box to 1.8 would make the tuning higher not lower. He would have to go with about 16 inches of port length to get 32hz.

a full 4" port is a little over 15" I'll measure one later I have 3 sitting here. I don't want to argue here is the manufactures site for aero ports

Calc

Excuse me a full length port in 1.8 = 33

This is why I wanted to know the ops reason, SPL or SQ ?? Before I cut my wall, I had a sealed enclosure with 2 10s under my rear seat. It sounded GREAT for SQ. And had nice thump to boot ...

I hear tell of extendable areo ports, but I have no idea how well they work. Check Parts-Express, unless someone on here can tell you more about them.