Why use ports? Confused about what I've read....

[MrSkippyJ]

I know that ported boxes produce better low end freq becasue they allow the drivers to move more air, but ported boxes are also "late" for bass response. Ex: if your listening to electronic music, the kick will sound delayed.

Ported boxes have a stronger low end (if done correctly) because they utilize the back wave as well as the front wave.

[SCOTT KOCH]

God bless america dudes........just build the dang thing and lets see some pictures..........There is such a thing as overengineering!!!!!!!!...If you build it they will come............

[vrollin]

God bless america dudes........just build the dang thing and lets see some pictures..........There is such a thing as overengineering!!!!!!!!...If you build it they will come............

The boxes I have built and are sealed, was just toying with the option of throwing some ports in them due to their volume being one of the specified volumes for use with a port....

[412 CVX]

Look, we can talk about theory and our experiences all day, but until you actually build one and try one for yourself, you'll never know what it's like. Everyone experiences it differently, so go grab a sheet of MDF and build one.

[vrollin]

Was just trying to gain an understanding of what exactly it achieves before making any changes, if it was going to do something I didnt want it to then I didnt want to waste my time

[STEvil]

whoever said to put a fourth order behind the seat is talking out there ass if you dont have a lot of space this will not work fourth orders require a lot of space along with sixth orders,,,,,if you want to do a blow through you can and it can be a ported box it may act like a fourth order though

im talking about the rear, different term to the usa, yous say bed, if you look as his build youll bee what i mean, to do 4,6 or 8th and only put aero ports through cabin rear wall as for blow through, there an illegal modification in australia, with out engineers report (cost $800+ to get one) and it will probably never pass, another option is to have an IVC done ($3500+), to be done basically requires the crash testing of a same vehicle to see the effects of the modification (our laws over here are very strict) so on his vehicle blow through is out of the question, 4th in bed ported into truck is doable or external ports, with 20ltrs net a psp 17" (18" or 45.7cm) port will give him 38hz (and if gross 40hz) with a 3" 75mm aero youll need 30" 76cm per box to be in the low 30's either way not looking good for his car

You can still do a blowthrough, just use a bed topper and open it through where the rear glass of the cab was. the short toppers (about 1/4 or 1/3 the length of the bed) work best because you can hang the box down into the bed of the vehicle through the floor of the "half" topper thus retaining most of your bed still.

[vrollin]

Thanks for the info again guys, another question, the Focal specs say to use a 2 3/4" internal diameter X 9 13/16" port, I cannot find a port in that width that matches that port length. Would I be able to use a different sized port, ie larger diameter shorter length? If so can someone point me in the right direction of the diameter and length I could run with instead?

[MrSkippyJ]

Are you sold on using a round port?

[vrollin]

nah mate, could be any shape, dont really mind?

[vrollin]

Hoping an illustration will help me get an answer with my next question.

Planning on building another box, same shape and size as previous boxes, so that I can drop them in place without changing all my work, however with a slot port on one side of the box.

Like so; Red coloured area being the volume of the port required given the size and shape of the box,

Now, given that the port is an odd shape, angled front, with top and bottom sections being a different length, will this achieve the goal of a ported box or will the odd shape screw with the airflow?

Or, am I better off with going a port shaped like this so that the top and bottom lengths of the port match?