my friend is building a box for me that will be 3.7 cf @ 27hz.My question is how much port do we need? what's the displacement for the port in that box? any help is appreciated

Square, round, slot...what do you need?

it'll be a slot port tuned to 27hz

What size is the baffle on which the port is going to be fitted?

I assume you are working in inches.

We`ll need this size so we can work out the best Port Area / length combination.

Or do you already have the size of the port?

If you know the size of your port all you`ll have to do is multiply the overall length x width x depth & divide the total figure by:....

1728 (this is the total amount of inches in a Cu.Ft. 12"x12"x12")

to give you the Cu.Ft. of the port.

Example:

Lets say the port is 6" wide (including the inner port wall) by "15 long and is 11.5" deep

6"x15"x11.5"=1035" Cu.In

1035" Divided by 1728 = 0.59

So the port takes up 0.59 Cu.ft.

The actual port area used to tune the box will be smaller due to the fact that you have to include the inner port wall (3/4 ")in the calculations to work out the actual volume that the port takes up inside the box.

Edited December 24, 200519 yr by Mega Heavy Bass

would tuning my box to 30-32 hz give the sub more range.I love the low bass but still want to hit the 40-50 hz range with some punch.Last box i had was tuned to 30hz and i liked it.Will i notice much difference from a 27hz box? any help is appreciated