How big to make a port?

[MuzZa0nXTC]

what woofers first off. and 90% of manufacturer's box plans suck dick. just stick with the 12-16sqin (14-16 recommended) of port area. 4*8.5 = 34sqin so that number is useless until you say how big the box they say has to be.

yeah well the thingo says that the box should be 1.75 cubic feet. but i wanna run 2 of those subs in the ported box.

[MuzZa0nXTC]

ya thats for an aero port/pvc port

yeah i want a damn slot port. i hate numbers.

[Guest]

yes but i want a slot port

so how do i work that out? ive been sitting here for so long trying to but i just cant do it lol

im really good at all the boc building and fibreglassing but when it comes to the math i just cant get my head around it

ok lets say your box is 15" tall, the port would then be 13.5" tall (assuming you're using .75" MDF wood) .75 for the top of the box + .75 for the bottom of the box = 1.5". so 15-1.5 = 13.5" port height.

now lets say that the box you want is 2cuft. so 2cuft * 14sqin per cubic foot = 28sqin of port total.

28sqin divided by 13.5" port height = just above 2 inches width.

[Guest]

yeah i want a damn slot port. i hate numbers.

if you hate numbers then why did you get into the car audio habit? its ALL numbers. thats all you ever deal with in car audio.

[MuzZa0nXTC]

ok lets say your box is 15" tall, the port would then be 13.5" tall (assuming you're using .75" MDF wood) .75 for the top of the box + .75 for the bottom of the box = 1.5". so 15-1.5 = 13.5" port height.

now lets say that the box you want is 2cuft. so 2cuft * 14sqin per cubic foot = 28sqin of port total.

28sqin divided by 13.5" port height = just above 2 inches width.

sorta think i get ya mate. just a bit confusing cos over here in australia we work in millimeters haha so my box measurements atm are 330 high, 320 deep and 965 wide. 2.7 cubic foot i think.

thanks for bearing with me on this one bro. you been a massive help.

[Guest]

yeah i want a damn slot port. i hate numbers.

car audio is all numbers. if you dont like numbers then why did you get into the habit? you cant just expect to turn a few knobs and have everything okey dokey. you need numbers to know how big a box to make, how big a port to make, how to figure out how much voltage your amp needs to output to get to a certain power level. etc

yeah well the thingo says that the box should be 1.75 cubic feet. but i wanna run 2 of those subs in the ported box.

how about you finally tell me what woofers? and model numbers.

apply the math i just told you, i cant hold your hand through this whole thing

edit: not meaning to sound like an asshole or anything. its just some people expect to be helped 100% through everything and not bother to figure out anything themselves.

btw 1.75*2 = 3.5 haha

Edited May 27, 2010 by Kranny

[EclipseChris]

I love these threads, because i STILL don't know some of the things said in here.

Thanks op

[MuzZa0nXTC]

car audio is all numbers. if you dont like numbers then why did you get into the habit? you cant just expect to turn a few knobs and have everything okey dokey. you need numbers to know how big a box to make, how big a port to make, how to figure out how much voltage your amp needs to output to get to a certain power level. etc

how about you finally tell me what woofers? and model numbers.

apply the math i just told you, i cant hold your hand through this whole thing

edit: not meaning to sound like an asshole or anything. its just some people expect to be helped 100% through everything and not bother to figure out anything themselves.

btw 1.75*2 = 3.5 haha

oh and also im confused cos the guy at my local auudio shop keeps telling me to make the box 2.2 cubic foot... so i dont really trust him lol

Sorry im not trying to get you to do it.. im just trying to understand lol truth is ever since i was a little kid i have ALWAYS loved this stuff when the rest of my family call it a waste of money. so i am really just trying to learn. soundsystems and cars is all i can ever think about so im just trying to get asmuch advice as i can get as there is nowhere near me that teaches this stuff.

Edited May 27, 2010 by MuzZa0nXTC

[Guest]

oh and also im confused cos the guy at my local auudio shop keeps telling me to make the box 2.2 cubic foot... so i dont really trust him lol

Sorry im not trying to get you to do it.. im just trying to understand lol truth is ever since i was a little kid i have ALWAYS loved this stuff when the rest of my family call it a waste of money. so i am really just trying to learn. soundsystems and cars is all i can ever think about so im just trying to get asmuch advice as i can get as there is nowhere near me that teaches this stuff.

oh ok. some people take longer to understand stuff (im a great example at this) than other people. especially since you have to work through a conversion barrier lol. and my family says the same thing to me.

lol 2.2 cubic foot doesnt make sense if the manufacturer says 1.75 for EACH.

[MuzZa0nXTC]

oh ok. some people take longer to understand stuff (im a great example at this) than other people. especially since you have to work through a conversion barrier lol. and my family says the same thing to me.

lol 2.2 cubic foot doesnt make sense if the manufacturer says 1.75 for EACH.

yeah thats why i joined this forum. cos i dont trust the guy at my local audio shop lol

i been playing with that torres calculator or whatever and with my boot measurments my box comes out to 2.7 cubic foot. hmmm still not big enough but i think i worked out the calculator so all good

thanks heaps for your help bro. your a champ.