Check numbers please?

[Bonka]

I downloaded a sketchup program to look at the SA box design but didn't do anything outside of that.

[Jessica]

on the second port section, did you factor in the thickness of the first port section in its lenght?\

[Bonka]

I think I didn't factor that 3/4" in but there's still a huge difference in the box volume. You're not supposed to count the port volume in the box volume correct?

[Jessica]

let me put it in sketchup and see what i get. lol

[Jessica]

i get 1.97cuft net using sketchup. here is the port lengths for a 28" long physical port. end correction not included. you could make the port about a half inch shorter and it would probably act like a 28" port

 

[Bonka]

Ok so I definitely did mess up that 3/4" on the port length and I miscalculated the volume  of that dotted section I had in my drawing because I didn't factor in 3/4" there either. I'm now coming to the 1.97 ft^3 you came to. That's roughly 33.25hz. I think this should actually be ok. I know SA recommends 35hz but I've seen people doing 33hz. If not I can recalculate to get closer to 35hz. Thanks for the helping me figure out what I botched there.

[Jessica]

one other note, your port area is a little low but you should be ok. 

 

[Jessica]

that is assuming you are running rater power to that sub.

[Bonka]

I'm getting the Hifonics Brutus BRX1100.1D which can put out 800w at 2ohm. I guess I could add more length to the port since the area is a bit low then.

[Jessica]

you would have to make the port bigger and box bigger and yes, port longer. You might have some port noise at tuning. Not to knock that amp but i think you will be fine. its fused at 60amps so i doubt it would do more than 750 even at 1ohm. doubt it will do 800 at 2ohm