Aero Port Displacement?

[bunkerking09]

1.8 cubes - 3.0 cubes, 20 - 48 Inches of Port, 32-37 Hz

imo i would do 5cuft after all displacement, tuned to 35hz w/16sqin port for those subs

16^2 total inches of port?

the box is looking at 6.5 gross before bracing, sub, and port displacement (which will be about 1.5 total) . But my ports aren't long enought to tune to 35 hz

[bunkerking09]

how much power are they getting, 1500w rms a piece or more?

3 4" ers would work well, ~37sqin port at 5cuft

realistically, no. It's going to be a fusion 4000D (surfboard) @ 2 ohms. I don't think i would want to run it at .5 daily with the electrical I have now. Its eventually going to turn into a 49.9 bass racer with 4 DP's & the fusion @ 1 ohm.

[Decaf]

well the bigger box will make up for the higher tuning but what kinda power are we talking about

if youre throwing 2000+ to them they have stiff enough spiders to allow to be played below tuning

i always suggest tuning no higher than 35hz for daily cause alot of songs lately are around 30hz and thats quite a difference from 37hz.... those are some loud subs tho, i heard pioneerpimps(from ca.com) 4 15s each 2 sundown3000ds at 153.7db@37hz iirc

[bunkerking09]

it will be a daily setup, but i'm still wanting it to be loud obviously. I'll worry about numbers later.

I will be giving these a lot of power, but i'm sure they'll be able to handle it.

So you think 3 4" ports would be better?

[Decaf]

to many sqin/cuft... ud likely be very peaky with so much port... this will also affect ability to play lower(if that matters), but could be a good thing if you want to be peaky at a certain freq

its very hard to tell how a setup will perform in a given vehicle, but likely sticking around 2.5cuft w/14-16sqin at 32-37hz would be best per incriminator's website

id stay away from too big of box and port especially if ur playing music all the time and giving them more than rated rms

[Nightshade]

Here's my opinion since I consider myself a 12" subwoofer guy. Keep the 4 4" aero's the length that you have them and do the subs in 4.75 cubes. If it's the psp ports that your using they actually come 18" from partexpress. On their site they list them at 17", but when you put them together and measure from flare to flare they are actually 18" long. The only reason I say to go with 4.75cubes is because you want to tune lower. The box in my sig is smaller than that but also has 4 4" aeros and you can see the kind of numbers it's doing.

[banginAltima]

Here's my opinion since I consider myself a 12" subwoofer guy. Keep the 4 4" aero's the length that you have them and do the subs in 4.75 cubes. If it's the psp ports that your using they actually come 18" from partexpress. On their site they list them at 17", but when you put them together and measure from flare to flare they are actually 18" long. The only reason I say to go with 4.75cubes is because you want to tune lower. The box in my sig is smaller than that but also has 4 4" aeros and you can see the kind of numbers it's doing.

Yes the total length is 18 inches but if you read what PSP-inc says, half inch on each side is not usable. So considering they are the ones who make the ports it would be best to go by 17 inches for tuning. For displacment you need to use the full 18 inches.

Now this guy said he is going to use it for daily for now and then spl (149.9 class later) It is best to use 3 four ports for daily now. That will get the tuning down for daily. Once he gets all four 12's then he needs to think about 6 inches ports and a new box too.

[bunkerking09]

Yes the total length is 18 inches but if you read what PSP-inc says, half inch on each side is not usable. So considering they are the ones who make the ports it would be best to go by 17 inches for tuning. For displacment you need to use the full 18 inches.

Now this guy said he is going to use it for daily for now and then spl (149.9 class later) It is best to use 3 four ports for daily now. That will get the tuning down for daily. Once he gets all four 12's then he needs to think about 6 inches ports and a new box too.

yea 4.75 w/ 18 ports will be somewhere around 45 hz. To high for daily.

[Nightshade]

yea 4.75 w/ 18 ports will be somewhere around 45 hz. To high for daily.

I don't know where you got 45hz from but with 4.75 cubes and 4 4" aeros 18" long that tunes the box to 37hz. Regardless of what you say too Gary 3 4" aeros is not enough port area in that large of a box. With 3 4" aeros in 4.75 cubes that comes out to be 7.9 sqin per cuft and is way too small. I pretty much only deal with 12" subwoofers and have for the past 3 years. You need at least 12 sqin per cuft for it to be fairly loud in a daily enclosure. I'm not sure if you've heard my car or not, but it happens to be tuned for a daily application and has a very flat response from 37-55 hz being that each of those frequencies are only within a few tenths of one another spl wise. All that and I'm still using a woofer with a fs of 43hz or more. The least I would ever reccomend someone running for 12" subs is 10 sqin per cuft period. Otherwise there is not going to be enough port area and will lack spl.

As far as the ports only being 17", every street spl competitor in Db Drag has told me to measure aero or psp ports from flare to flare. Even when making your own ports you need the length to be from flare to flare as well, so 18" is what I've always went by since that's what spl experts have told me to use.

[banginAltima]

I don't know where you got 45hz from but with 4.75 cubes and 4 4" aeros 18" long that tunes the box to 37hz. Regardless of what you say too Gary 3 4" aeros is not enough port area in that large of a box. With 3 4" aeros in 4.75 cubes that comes out to be 7.9 sqin per cuft and is way too small. I pretty much only deal with 12" subwoofers and have for the past 3 years. You need at least 12 sqin per cuft for it to be fairly loud in a daily enclosure. I'm not sure if you've heard my car or not, but it happens to be tuned for a daily application and has a very flat response from 37-55 hz being that each of those frequencies are only within a few tenths of one another spl wise. All that and I'm still using a woofer with a fs of 43hz or more. The least I would ever reccomend someone running for 12" subs is 10 sqin per cuft period. Otherwise there is not going to be enough port area and will lack spl.

As far as the ports only being 17", every street spl competitor in Db Drag has told me to measure aero or psp ports from flare to flare. Even when making your own ports you need the length to be from flare to flare as well, so 18" is what I've always went by since that's what spl experts have told me to use.

Well, you have the right to believe what you want to and so do I. Three 4 inch ports will work great for a "DAILY" box for his guy.