The Port Area Thread

[numatik]

So,

Many years ago we (me included) would put as much bass as possible into our car or truck. We have our magical ways designing the perfect enclosure for what were doing, but when it came to port, it seems we all use the 15-18sqin port per cubic foot of enclosure. Then if its a monster system, we 'add a little bit more'.

There must be a real formula, for any application.

For my daily dragger, I have a jl 10w7 and 18sqin of port per cubic foot seems like a little much especially on a less then 2 cube under seat enclosure. For me, i have built alot of big systems, and several small ones when i was an installer at Sundance and Audio Express. But those of you who work at beat shops also know everything thing is about how fast you can get it in, and prefabs are awesome for tucking bass into tiny places. For higher paying customers I would do the same style big systems I would do for myself. But this is my truck and i dont do prefab for me. Eyeballing it it looks like il be using 4"ID round tube for a port, but I'm ashamed to say I do not know a formula that can tell port for 10" sub, and port for 4 18s using the same rules. Please correct me if on wrong?

[hdorre]

http://www.carstereo.com/help/Articles.cfm?id=31

[numatik]

http://www.carstereo.com/help/Articles.cfm?id=31

Thats nifty, but dosnt answer the question exactly.

EDIT:

just playing around with one dosnt seem accurate either. It looks at some variables, but dosnt know if thats a 1 cubic foot enclosure or a 10 cubic foot enclosure, and between those two factors could be a farrrrr differ port size port.

[hdorre]

http://www.carstereo...icles.cfm?id=31

Thats nifty, but dosnt answer the question exactly.

Oh, I skipped over the part where you said you were looking for the ACTUAL formulas..sorry

http://www.carstereo...icles.cfm?id=21

[numatik]

Oh, I skipped over the part where you said you were looking for the ACTUAL formulas..sorry

http://www.carstereo...icles.cfm?id=21

Maybe im just a tweaker, i was looking for one more in depth, but this is def on the right track, and you found it fast!

[hdorre]

Eh, sorry I couldnt find what you were looking for. This forum is extremely active around midnight (my time), so maybe youll get a few responses then.

[AMI CUSTOMS]

And that is still minimum vent not optimum. So really quite pointless, called trial and error there bud. LOL

[RAM_Designs]

just playing around with one dosnt seem accurate either. It looks at some variables, but dosnt know if thats a 1 cubic foot enclosure or a 10 cubic foot enclosure, and between those two factors could be a farrrrr differ port size port.

The size of the enclosure has nothing to do with how much port area you'll need. It's dependent on how much air the sub itself is going to displace and the frequency at which you'll be tuning. The same sub moving the same amount in two different sized boxes will not need two different sized ports to "avoid port noise."

[hdorre]

And that is still minimum vent not optimum.

So really quite pointless, called trial and error there bud. LOL

I forgot to mention that

Youre so blunt haha

[AMI CUSTOMS]

There is also one other little thing people often overlook called the vehicle it is going in, take the same exact enclosure put it in an SUV, a car, and an extended cab pickup, one or two of those vehicles the sub will likely unload under certain conditions, ei windows up down, door open closed, direction of sub and port. Again Trial and error is your friend.