aero lenght? All numbers here, calc confuzzled me

[WOT]

Building my box in a few hours and psp's port calc is down

Im trying this site http://www.carstereo.com/help/Articles.cfm?id=31 but Id love to get input from another source. Only thing that may be different is I dont know if this site takes into account displacement, or flared ends. Im running aeroports, but they wont be mounted flush against the box baffle, they will be spaced out 3/4" away...... how do I account for this....

Looking for accuracy on this build

Box is 36" wide, 31" tall, 23" deep.

.75" wood

12.66 cubes internal

Im going to be using (3) 8" aeroports, both subs combined displace .66 cubes

Going for a 38hz tune I get 17.6" long, but.... variables. I dont know if that means 17.6 of STRAIGHT port, plus flares, or is that total length end to end including flares

I dont know if this site takes into place displacements or anything though

Any help appreciated, hoping to bang this out if it stops raining in just a couple hours

Click to read more...

 

[WOT]

buuuuuump, going to get the wood nowzers

 

[Buck 5,000+ posts]

Are these the 8" aeros on on ebay?

 

[WOT]

Naw man i made these myself, cant figure out how to use the calc accurately though, how do you figure the displacement of the 3 ports, if you dont know how long they are gonna be???????

 

[fasfocus00 5,000+ posts]

i got ~21" of port lenght for 3 8" aero ports to tune to 38hz. you should roughly have a total port length of 1" longer than what you actually use, i.e if your aero port is 18" long from end to end, you port length is 17".

 

[Buck 5,000+ posts]

Naw man i made these myself, cant figure out how to use the calc accurately though, how do you figure the displacement of the 3 ports, if you dont know how long they are gonna be???????

You gotta guess at cubic feet and then just change and change until it gets right.

 

[WOT]

i got ~21" of port lenght for 3 8" aero ports to tune to 38hz. you should roughly have a total port length of 1" longer than what you actually use, i.e if your aero port is 18" long from end to end, you port length is 17".

You lost me, using psp's port calc, like when it says 18" flared port length, that means end to end including flares right??