hey just like the title, need some help with porting my new boot install/sub box

its a 15" Xplode 450 Watt RMS sub powered by a jensen 400watt RMS amp
box size is roughly 102 L, i know its a bit big its only a rough estimate, probably is closer to ~85 L which should be a good size for a ported 15"

the port is a 70mm diameter port, main question is how long should it be and how do i tune it(n00b i know), never really tuned a sub before (not properly).

thanks for all your help in advance

well, we cant really help you not knowing what sub it is, each sub has its own ideal box design, usually on the pieces of paper in the box when you buy the sub, best bet would be goin on the net and finding the specs

you'd want to drill a bigger port into the box. 2.7" diameter isnt big enough for most 10" woofers ler alone a 15", there would be bulk port noise produced, and it would be really inefficient.

a 5" port would be ideal as a generalisation, maybe even 4" from the sounds of your sub. if it is indeed 102L gross, given port and woofer displacement your box is around the 3cuft mark. if you go the 4" port, about 120mm long would give you a 37hz tune, which is a fairly good point as standard for most woofers.

be aware that the box will not be optimum, but should sound a hell of a lot better than it does atm, it takes a lot of work to make a 'perfect' box :) bloke i talk to who has won world SQ competitions made one of his best boxes out of 18mm HDF, a 10mm layer of sand, then another 18mm HDF layer, cost something like $6000US to be designed for the customer due to the process of getting it right.. but whatever sounds best to you :)

if you want to get the box a bit more accurate to your sub, i suggest you download WinISD, great program with a lot of drivers in their list already, or you can input your own specs.

you'd want to drill a bigger port into the box. 2.7" diameter isnt big enough for most 10" woofers ler alone a 15", there would be bulk port noise produced, and it would be really inefficient.



because i already have the 70mm port, would two 70mm of equal length be the same as a 140mm single port? otherwise i guess ill go buy a new one :cry:

if you got a hole saw, you could just cut a bigger diameter over the existing hole.

and no, 2 ports 70mm long would equal 70mm, just with more port area sorry to say.
it would also make your tuning frequency double what it is with the 1 port, which is bad :P

ok then i guess ill grab a new port

something like jaycars 110mm port
http://www.jaycar.com.au/productView.asp?ID=CX2684&CATID=15&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=274