Big Woofer

[Oklahoma Wolf]

It's here:





Looks smaller in the pics than it really is. It completely dwarfs the old Akai and the two 15's right next to it.

Next step - build the box. I figure when that's done I can worry about the amp. The way our weather's been, winter could be starting again at the end of July and I need the box done first

[Zero82z]

Originally Posted by Oklahoma Wolf

The way our weather's been, winter could be starting again at the end of July

Did we just go back in time?

[Oklahoma Wolf]

It feels that way.

[madmat]

How big of an enclosure are you building?

[Oklahoma Wolf]

About 405 liters after bracing tuned to 11.5Hz. It's going to be a big box. 48x24x24."

[madmat]

You do know that with a box that size you'll need 184 square inches of port area and a port 274" long, right?

[Oklahoma Wolf]

Not really. I'm basing it off this design, slightly modded: http://www.avsforum.com/avs-vb/showthread.php?t=875108

I don't like the bracing strategy - I'm using 2x2's.

The port's going to be 6" in diameter and 38" long. It models ok in Bassbox and WinISD, but the vent speed could be lower down at the tuning frequency. I'm justifying it by figuring not much content is going to get down to 11.5Hz.

[madmat]

I'd at least use a 6" aeroport. That's way, way too much box for that port. You're supposed to have 16 square inches of port area per 1 cu ft of box, you have 14.3 cubic feet of box before displacement.

[Oklahoma Wolf]

I'm aware of how it's "supposed" to be done, thanks - not really new to this

I wanted to use an 8" port - the software killed that one pretty quick. Port resonance is too low and it won't fit the box. Two 4" ports would do, but vent velocity is even higher than one 6" port. As it is, I get around 18m/s at the tuning frequency... I can live with that. It rolls off pretty quick above that, and port resonance is around 160Hz. 7" might be a decent compromise, but then I have to worry about finding something in that size or building a little square tunnel in there.

According to Bassbox, I actually have the box volume at 450L (16 cubic feet), after the bracing and driver. Port is actually 36" long. It's going to be tough finding PVC pipe in that diameter - I looked for it in Swift Current yesterday, and nobody had any. Need to hit a major city for that I guess.

Edit - 415 liters. Was looking in the wrong place - it's 450 before all the goodies.

[madmat]

Aeroport, aeroport, aeroport....