Aero port once more.

[robertoyoung08 10+ year member]

aah here it goes again.

need some final help with aero port.

been doing some MORE numbers, but i want to make sure i have it right.

4.5 cubic foot box. need tunning to 33 hz.

- i can do one 6 inch aero at about 12 inches in length (but would end up being really close to sub because where exactly i want both the aero and sub to go they happen to meet up)

- or two 4 inch aeros at a little under 12 inches in length.

someone give me some advice. which would work best for my box also considering trying to avoid port noise.

thanks a lot, so far i've gotten a lot of help from you guys on here. didnt know nothing when i first started out with this box and im working my way up there. however since i dont know much about how to calculate all this please try to give me some straightforward answers. i keep reading and being told about "the rule of thumb" when it comes to aero ports and how much sq inch of port should be put in per cubic feet, but im completely new at this so i hardly know how to apply that to my calculations.

must be annoying to help a rookie but thanks again. really appreciate it!!!!!!!!!!

Click to read more...

 

[7ender 10+ year member]

That's a very small port, even for an aero. Iv'e used a 6" aero on my 4.1 cube box, but that's the absolute smallest i'd go.

The rule of thumb you hear of is how many inches of port are you'll want per cubic foot of box. For aero's, i'd try to stick with around 8-10" per cube.

If you're trying to avoid port noise, i'd definetely go bigger. My current box has a 7.5" aero and it's 4.5 cubes, and it's probably my favorite box so far. It comes out to a little under 10" per cube of port.

If you're wondering where I got the odd size aero...go to home depot and look for sonotube. They make it in an 8" diameter, but they vary in size (the 8" sono's go from 7.5" to 8.5").

 

[robertoyoung08 10+ year member]

hmm okay.

looks like now i have to reconsider everything lol

but thats alright, im trying to get it right.

i found some 8 inch with flares on ebay so maybe i could get one of those.

but which of the ports would you say is too small, the one 6x12 inch? or the two 4 x12? or both?

figuring out aeros is harder and it seems like they take up more room than a slot port. aero is my only way though, since im trying to place it at the top of a box so it will fire upwards into the cabin of the car.

i havnt been able to figure this out. i figured out the numbers i got with precision sound prodcuts (psp-inc) tool calculator. and i emailed them and they said to use that, a few other people told me that was one of the most accurate too, but i did find the number to sound a little sketchy a lot of the time. i did use car stereos round port calculator and it gave me a minimum diameter of i think 7.3 inches, or something like that, so i do think your right on needing at least a 7.5 diameter.

what do you have your box tuned to?

 

[7ender 10+ year member]

Did you read my guide? Aero's take less volume than slots, because you dont' need as much port area.

Both those ports are too small. A 6" aero gives you 28" sq inches of port, and two 4's gives you 25".

 

[mazdakid 5,000+ posts]

an 8" aero would be nice for a box that size

 

[7ender 10+ year member]

an 8" aero would be nice for a box that size

that's what i'd go with as well.

 

[mazdakid 5,000+ posts]

the guy thats selling the ones on ebay is on the forum and sells them here.

 

[robertoyoung08 10+ year member]

alright, im getting somewhere now.

im getting some really good suggestions, thanks everyone.

so how many sq inches of port would i need.

im not sure how i would figure how many square inches of port im getting per cubic foot. if i go with 9 inches of port per cubic foot, how do i figure length/diameter of aero?

well at least to try and make it easier, if i was to go with that 8 inch aero, what would the length be? about 13?

my box is odd shaped, where i will place the aero is only 14 in in height, so that might present a problem. which is why i was trying to figure out smaller ports, maybe 3+ 4"aeros

i want to get this down soon. im installing a whole system in my car car, box is the only thing keeping me from installing it all.

 

[perfecxionX 10+ year member]

I have been told that port area is never determined by box volume. People develop these 12-16" per cube rules of thumb for the ease of it but port area is better determined by the air displaced by the driver. So to answer your question without knowing what type of sub or power is being used would be a pretty hazardous guess.

With that said, in my personal experience one 6" aero should be enough for a single 15. what kind of sub is this box for?

 

[7ender 10+ year member]

Again, have you read my guide? Alot of your question have been covered in it already. It's a few topics below yours in this forum section...

 

[robertoyoung08 10+ year member]

have you guys read perfecxionx's response?

i havnt read your guide, i cant find it. i will look again.

 

[robertoyoung08 10+ year member]

I have been told that port area is never determined by box volume. People develop these 12-16" per cube rules of thumb for the ease of it but port area is better determined by the air displaced by the driver. So to answer your question without knowing what type of sub or power is being used would be a pretty hazardous guess.
With that said, in my personal experience one 6" aero should be enough for a single 15. what kind of sub is this box for?

yeah, i keep getting different things. a six does seem big enough, but ive never done aero so i really wouldnt know. what would you say?

its a 12 inch RE audio MX

will be pussing about 1500 watts rms.

in a 4.5 ft^3 at 33hz

 

[robertoyoung08 10+ year member]

Again, have you read my guide? Alot of your question have been covered in it already. It's a few topics below yours in this forum section...

ha okay nvm

i found it. was looking way too far.

 

[perfecxionX 10+ year member]

yeah, i keep getting different things. a six does seem big enough, but ive never done aero so i really wouldnt know. what would you say?
its a 12 inch RE audio MX

will be pussing about 1500 watts rms.

in a 4.5 ft^3 at 33hz

why so big? you realize thats more than 2x RE's recommended size?

http://reaudio.com/specs.html#sp_mx

 

[robertoyoung08 10+ year member]

now im getting even more confused.

okay, just tried that formula again and nope cant come up with ANYTHING that looks reasonably right.. AT ALL.

i would like to get the answer to this box already.. but now im also more interested in actually understanding this.