Double check my math please

[kickin'kia]

Ok so I have been trying to make a ported box out of an old sealed box using an aero port.

The box is 16x16x18 which is 2.01 cu ft

now if I mount the port externally It will remain 2 cu ft and I want to tune aroungd 33hz so I punched some numbers and if I use a 4" aero port (flared both ends) I think I only need 12.62 in long.

Is this correct? If so is that enough port area for that box? Can someone tell me how to calculate port area? And how much cu ft would that take if I put the port inside the box? I know if I put it inside I would have to readjust the tuning but just to get a rough idea.

[Torres]

port area for aero ports is figured by pi * radius ^2 (squared). so 2 * 2 * 3.14 in your case. one 4" port gives you 12.56 sq inches of port. a little on the low side. i believe aero ports are recommended for 9-13 sq inches of port per foot. but does give you the tuning you say. so you're accurate in all those areas. port volume is .09 cubes.

[kickin'kia]

port area for aero ports is figured by pi * radius ^2 (squared). so 2 * 2 * 3.14 in your case. one 4" port gives you 12.56 sq inches of port. a little on the low side. i believe aero ports are recommended for 9-13 sq inches of port per foot. but does give you the tuning you say. so you're accurate in all those areas. port volume is .09 cubes.

is there a size or different combonation of aeros that would be better the box it is 16w-16h-18d. it has a single 12 in it.

[bkolfo4]

is there a size or different combonation of aeros that would be better the box it is 16w-16h-18d. it has a single 12 in it.

What 12" woofer, and how much power are you running? A single 4" may work just fine.

Also note that you need to add 1" to the calculated length for end correction on the 4" aero, so your port would be 13.62" long.

Brian

[bkolfo4]

I also should mention - you need to account for driver displacement, which will further reduce the net volume and require a longer port to stay tuned at 33 Hz.

If you put the port inside the box, it will displace ~0.1 cuft and have to be ~1" longer.

By the time you factor in driver displacement and port displacement, I am going to guess you will not have enough depth for the port length required (you need 4+ inches behind it for it to work properly) to have it inside the box. You might could add a spacer ring to the surface you plan to mount it on, or raise the tuning slightly.

[kickin'kia]

I also should mention - you need to account for driver displacement, which will further reduce the net volume and require a longer port to stay tuned at 33 Hz.

If you put the port inside the box, it will displace ~0.1 cuft and have to be ~1" longer.

By the time you factor in driver displacement and port displacement, I am going to guess you will not have enough depth for the port length required (you need 4+ inches behind it for it to work properly) to have it inside the box. You might could add a spacer ring to the surface you plan to mount it on, or raise the tuning slightly.

well right now the 12 is a kicker cvr but It will be a dc level 3 12 soon i am just making the box for the dc but putting the cvr in it until i get the dc. would the 4 inch be ok?

ok well I will probably make a new box then I was just trying to recycle and save a few bucks. Now should I stay with aeros or should I use a slot ported design I already made from exposports calculator?

my new box will be wide like 34w-14h-10d so i can push it back for more cargo area

thanks for the help