Port Question

[mega1268 10+ year member]

Ok im Fiberglassing my Tire well and putting a brahma 15 in there. I fiqure it would be much easier to put a circle port in it. I went to do a port Calculator and it said 3 inch diameter and it only has to be 3.14 inchs long....... does that sound right? it seems short i wanted to tune it to 28Hz Seems alittle short to me.

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[g30ffr3y 10+ year member]

i had a similiar experience when i built my

round ported box...

everyone says you need ten billion square

inches of port and this and that...

i have a 3" diameter port thats 6.26" long

is tuned to ~32hz and i get no port noise...

i would say your port is right on...

now if you WANTED to have a gigantic

port you could go with dual ports or

quad ports or a larger diameter would

make it so you needed more length...

but for a spare tire well fiberglass job

i dont suppose you want to have to deal

with all that...

i would say go with it...

 

[mobileaudio219 10+ year member]

Use a bigger port, 5.51" perphas.... With a 3" port you will experince nasty port noise, somebody correct me if Im wrong...

 

[pj_chevy03 10+ year member]

one 3'' port seems a little small especially for a brahma 15.

only about 6-7 sq.in. of port area

 

[mega1268 10+ year member]

alright i have this port calculator http://www.carstereo.com/help/Articles.cfm?id=31 and i wanted to know if this is actually good to go by. Im not actually postive how big my Wheel well is but i would say between 2-3 Cuft Over the weekend im gonna Fill it up with packing penuts and see how that goes. But What is the problem with Round ports ive heard alot about port noise. Would it help if i get those Flared ports. Or what should i do.

 

[mega1268 10+ year member]

Help???

 

[req 5,000+ posts]

flare on the inside would help. if you can, find some 6" pvc pipe. that would help. make sure you sand down all the edges after you cut it.

you can always mount the port like the baffle, and stretch the fleece over it if its too long. thats what id do. it would look cool too.

 

[DFW40 10+ year member]

According to this site you need 10 inches of port diameter if it were PVC or 80 square inches for a slot ie: 4 by 20 slot. With a 15 I'd use no less than dual 4 but you can try more or less.

 

[req 5,000+ posts]

depending on the power that is going to it, and if his trunk is sealed or whatnot, should depend on port velocity.

personally, id go with around half the Sd (cone area) of the driver. maybe a little less. but then again, the box would increase in size. but thats the beauty in fiberglass. you can make it as big as you want //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif