TragicMagic

PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES

Specs on the 7200 show that the XMax is .7", or about 17mm., one way.
I want to tune the box for better SQ, hence the lower number.
From what I can find the recommended vented enclosure volume is 2cu.ft. But that's not from Eclipse, so I need to have that confirmed. (MR2NR)



I'm having a hard time figuring out how to design a box that is 2cubes, and is tuned for 33Hz. Seems like the port length has to be really long in order to achieve that tuning, problem is fitting it into the box, then determining how much volume the port walls are displacing.

I know some ports are L shaped, but could you get away with having two corners?

Can someone take a few minutes to see if they can design something that'll work?

Thanks guys.

jalat

iTrader: (6)

2 cubic foot enclosure will need a 13" long 4" port to achieve a tuning of 33hz

TragicMagic

How'd you figure that out so fast? The 4" is the length of the sides of a square port? 16sq.in of area, right? Would there be a problem with using a 2x8" slot port? Will the narrow 2" cause port noise? I'd kinda like to be different, and put a square port on the lower corner of the box, just not sure if there'd be an adverse effect as a result of that placement.

So one piece of the port would be 4x13", and the other would be 4.75x13"...the other sides would be part of the main box. By my math that would result in 85.3cu.in of displacement for the port walls.

jalat

iTrader: (6)

my calculation is refering to if you were using aero ports which i think would be your best bet. your idea of the square slot in the bottom corner of the enclosure would work, but you would have a good amount of port noice. either aero port it or slot port it. i still think the aero is what you want.

Edit: for 33hz, you closer to 14" long 4" diameter aero port