Please check my work + confused (torres' box calc)

[Hifonics]

I'm trying to play with torres' Box Calc because I'm going to be helping some friends with boxes this summer... I need to learn how to use it properly. Here's what I have so far (box is for an 18" AA mayhem):

which will look something like this (forgive my fail paint skillz):

My question(s): Does my design look ok for a 18" Mayhem? Also, why is my physical port length 21.75 when I asked for 30"... and if it is that long, why do I need a port bend? I have no idea where to start the bend. I dunno how do cut my wood for this I am so confused. If anyone has any suggestions or could shed some light on this that would be greatly appreciated!

[Joe X]

Your usage of Torres is ok but for that particular design you would need at least a double baffle and bracing for that to work.

[Hifonics]

Ya I was just messing with it. I'm gonna use your design for my personal box. I just don't understand how to cut the port based on the output from the program.

[Joe X]

You follow the centerline of the port. here is an example from another design being the port length 31", take a look:

[Hifonics]

Thanks Joe! I get it now I'm a visual learner... I owe you a beer good sir.

[Hifonics]

After looking at the torres output I find it's still not making sense... if I want 30" of port and I have 35" of length available then it shouldnt need a bend... right?

[Joe X]

What happens is that the port cannot near the back wall (the bottom wall in this case) more that 7.5" (same as the width), this is a typical issue, the tuning you want makes the port near the corner, so one needs to play with the port area, the size of the box, etc to get off the corner.