[whines]

I started construction of a box for a Dayton 15" DVC subwoofer--WinISD suggests that it'd be happy with a modest 5.5cuf enclosure, and I'm porting it tuned to 23hz. Sadly I wasn't paying very close attention to the port speed, and I've realized that I need a LOT more port that I had originally allowed for.

The box is 36" tall, 16.5" wide and 16" deep (inside dimensions).

I'd rather not scrap the box, so I'm thinking of adding an external port, 10"x4" and 32" long.

My questions are:

* I've seen some references that suggest that the port should be near the woofer itself so that the phase of sound coming out of both will be in synch. Is this a signifigant factor? If it is I'm thinking of having the port exit the back of the cabinet and then wrap around the underside, opening at the front bottom of the cabinet. I assume I'd want the cabinet up on legs to get the port a few inches from the floor.

* Does the port need to extend signifigantly into the box? I've seen some examples of boxes with square ports and they seem to usually open along the side of the cabinet and then wrap around it--but I've also read that ports should not open within 3" (or the diamater of the port) from a cabinet wall. Should I take this into consideration?

Thanks for your thoughts and input!

 

[collo]

It doesn't matter where you place the port inlet as long as it can breathe.

For the frequencies that the port operates at, the wavelength is large in relation to the box size, so there isn't any great variation in phase.

The port doesn't need to extend into the box at all.

With that area you probably don't need flares, but you should round over the ends with a rollover bit.

 

[whines]

Awesome! I'm building the port into the stand, then...folded 10x4 port equals a nice stand for the cabinet. Internal edges have been rounded off.

Thanks for the help!

 

[collo]

Good luck with the build!

We will be needing pictures....

 

[Mike P.]

Yes, please post some pics. We would love to see this!