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View Full Version : port size for sundown E8



BrownVanMan
12-22-2011, 08:15 PM
i tried using this site Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators (http://www.the12volt.com/caraudio/boxcalcs.asp) to figure out my aero size and with a 4" port .6 cubes and a tuneing freq of 30hz like its says on the website it says the port needs to be 59 inches long.....


just wondering what im doiong wrong and how to figure it out manually for future reference.

ItsAJeepThing
12-22-2011, 08:21 PM
Having the same problem with the same sub

BrownVanMan
12-22-2011, 08:24 PM
yeah its a sunuva *****. i am putting the last 2 sides on the box tonight and still dont know what port to get. i have .7 cubes before displacement and after port and sub ill be at .6 which should be about right

duanebro
12-22-2011, 11:12 PM
The smaller then box, the longer the port needs to be. So the calc. is most likely correct. This is why making a box for these high output 8s is such a pain.

winkychevelle
12-22-2011, 11:28 PM
try a smaller port a 3inch port would be more than enough do to the low xmax of the e8 even a 2 inch port would suffice

Falcons
12-22-2011, 11:29 PM
or do multiple aeros.

RAM_Designs
12-22-2011, 11:34 PM
A single 3" is plenty for that sub...still going to be long though and will need to be custom made with your own PVC.

BrownVanMan
12-23-2011, 12:40 AM
Calculator said 1 and One eight by 4.25 inches would get me where I wanna be. That sound right?

duanebro
12-23-2011, 12:45 AM
Calculator said 1 and One eight by 4.25 inches would get me where I wanna be. That sound right?

its not big enough. give me a few minutes. how long can the port be and still work for you?

RAM_Designs
12-23-2011, 12:49 AM
If you're going to use a slot port, try to get around 10-12in^2 of port and round-over the inner and outer openings to reduce the chance of port noise.

BrownVanMan
12-23-2011, 12:56 AM
13" is about max length

Tek18
12-23-2011, 12:59 AM
get a big long water hose and make sure its 59" long and theres your port!

duanebro
12-23-2011, 01:01 AM
2" aero 14" long. You will have port noise.

3" round port (pvc) 33" long. looks better.

BrownVanMan
12-23-2011, 01:04 AM
If you're going to use a slot port, try to get around 10-12in^2 of port and round-over the inner and outer openings to reduce the chance of port noise.

Going with an aero

BrownVanMan
12-23-2011, 01:08 AM
2" aero 14" long. You will have port noise.

3" round port (pvc) 33" long. looks better.

I wanted to go with a big port but box is 9x9x 23 OD

duanebro
12-23-2011, 01:11 AM
What amp are you going to use, how much power? And what car or truck?

BrownVanMan
12-23-2011, 01:17 AM
87 Toyota pickup, reg cab, center counsoul box. Amp is an infinity that's rated at 312 or something odd at 2 ohm. So anywhere between 200 and 300 watts.

kushy_dreams
12-23-2011, 01:26 AM
Anyway to mount the sub outside the box? If you did that and raised tuning to 33hz with a 3in port you'd only need about 23in of port length.

BrownVanMan
12-23-2011, 01:28 AM
23 was OD. Inner would be max length of 18" with a 3" aero

duanebro
12-23-2011, 02:49 AM
You are going to need to rethink the whole plan. Unless you can use a external port. (I wouldn't think that you would want to in a cc box) Can you make the box any bigger? Or use 2 sealed.

BrownVanMan
12-23-2011, 03:10 AM
That's the pRoblem I ran into. Box is already maxed out. I'm gonna leave it sealed for now then add the aero when I figure out what I need.

BrownVanMan
12-24-2011, 02:31 AM
Any other ideas? I might just go with the small port. Hopefully it won't sound like ***.
Am I better off goin sealed?

duanebro
12-24-2011, 10:26 AM
I'd go sealed over a tiny port. IT would take two of the subs sealed to equal one ported. The good news is that they only need a tiny box sealed.

I would recommend a different sub if you don't have this one yet. These subs get their spl by having a peak at tuning. With out that boost they just don't get very loud.

BrownVanMan
02-08-2012, 12:24 AM
well i just got the flared 2 inch aero off parts express which should tune it to about 34hz. we will see how it sounds. as of now in .7 sealed its way to big, likes to bottom out on hits.....

Moble Enclosurs
02-08-2012, 03:12 AM
I'm curious, if you are bottoming out in a .7 sealed, what is your voltage at? Is it over 20v?

BrownVanMan
04-13-2012, 06:12 PM
just an update, the 2 inch flared port is working great, and the bottoming out is because (i didnt know this then) i have a pioneer HU with the pico fuse issue. i would hit a big bump in the truck and the **** thing would hit super sayin mode. so far ive eliminated most of the noise and its better but i need to still do somemore wrapping of the wire behind the deck.

Moble Enclosurs
04-17-2012, 01:06 AM
Glad to hear that you have made progess! Keep it up and thanks for the update! :D

BrownVanMan
04-24-2012, 10:10 PM
yeah its pretty impressive. just rolls off really quick at about 32HZ but at 200ish watts and an 8 i am happy

mpsound
04-26-2012, 03:54 PM
Can the port ne located on the outside of the enclosure

mpsound
04-26-2012, 03:58 PM
Never mind computer never updated

Moble Enclosurs
04-26-2012, 08:15 PM
The optimum area for the v1 is bigger than the v2. The v1 requires about 174cm^2, and the v2 is about 142cm^2 due to them needing different tuning frequencies. This is for a conventional idea and obviously can be changed to match the designs layout and response. :D

BrownVanMan
04-26-2012, 10:53 PM
yeah i do have the V2

with a 2 inch port about 12 inches long im looking at only 37.8^2 inches of port?

Moble Enclosurs
04-26-2012, 11:03 PM
yeah i do have the V2

with a 2 inch port about 12 inches long im looking at only 37.8^2 inches of port?

It should have said cm^2. Changed. :D. But as far as having a 2inch diameter, that would be close to 19 inches high for yours. That ratio is more than the optimum ratio maximum for a port anyhow, which should be 8:1 or less. This one would be 9.5:1 if it were 37.8in^2 and a 2 inch width. This can cause unwanted resonances and noise factors jsut to let you know. I would recommend, depending on the height you have, say 10" as an example, to be 10 x 2.25" minimum for the v2. And any 8:1 or less ratio of that area is good to work with. :D

BrownVanMan
04-27-2012, 04:31 PM
So your referring to a slot port then, I want to make another box (have another 8) but the issue is the box is my center consoul. So if I used that 2.25 inch wide port with a 10 inch length, the sub would be right on top of the port opening. Wouldn't that cause some issues?