View Full Version : Should I add a port tube to my box?

09-24-2010, 05:33 PM
I have made the box for my sub and it has enough volume according to the manufacturer to be able to make it a ported box. I'm just trying to figure out if I will benefit by adding a port or if i should leave it sealed. The box will be under the helm btw.
The amp is an Alpine MRV-T320 so the sub should be getting 220 Watts.
The sub is a 2003 model 12" Kicker Comp VR with a rating of 400 watts rms.
The box is 16x22x11.


09-24-2010, 05:56 PM
Pay very close attention to the manufacturer recommendations for a bass-reflex enclosure. If its not right sound quality will certainly suffer but if its right it will be like taking the governor off. A ported box will take considerably more displacement than a sealed and some of that will be the port and port wall volume. So if displacement is too tight then you can always compensate by installing a majority of the port external to the box as to not reduce the box volume. And if the box is still a tad small you can adjust the port longer to tune at the same frequency (to a degree).

Earmark Marine

09-24-2010, 09:45 PM
Bz -

It's not as simple as stuffing a port into the wall of the box. My quick answer is listen first to the sound of the sealed setup and give it an evaluation. If it sounds great to you leave it alone.

If you choose the path of the port, I'd suggest asking Phil to model you a ported box design that will be tuned in accordance with the kicker woofer specs. We regularly do this for guys running custom Exile setups.

In a nutshell what David was speaking about is the port you us and the length of the port you use will tune the output to a certain frequency. Which may or may not be a efficient setup for your woofer. Again, not the place for hit or miss stuff. From there you could add poly fill to your ported enclosure to help fine tune the response.

exile audio

09-24-2010, 10:17 PM
That box design is SICK!

You really need to post pics when you get it installed. I was thinking about building the exact same type of box so that I can simply extend the kick plate.

Good job!

09-25-2010, 12:07 AM
Thanks, i'm gonna take the boat out out tomorrow and see how it sounds and then i'll decide if the port is necessacry or not Hopefully not, it seems like you need a lot more knowledge than I have to do it right. I won'thave the box carpeted by tmr but I'll be sure to take some pics.
David, I saw on your site y'all have subwoofer grills with the supra logo do you by chance have any with the moomba logo?

09-25-2010, 01:34 AM
Sorry Bz, no badge for a Moomba. But, its easy enough to convert the badge to another logo. I have the dual vinyls, black and brushed, in stock plus the Moomba logo in the computer. You would just need to take those ingredients to a sign shop to have the vinyl cut on a plotter.
Btw, before you are all finished plan on slighty elevating your box off the sole and slighty spacing the box off the hump with polymer (hdpe or other) pads.
Any coating you use, trunkliner, poly resin or epoxy resin will eventually fail if you don't build in drainage. The surface and seams that would rest against the carpet are most vulnerable. And, its very important that you aid evaporation so that you are not creating a mildew and mold trap. All issues that may take a season to become a problem but are completely resolvable in advance.

Earmark Marine

09-25-2010, 12:26 PM
Hey thanks for the heads up on the drianage I would have definatley overlooked it otherwise.

Also on the subject of the subwoofer grills are you saying I could get this grill and have a a sign shop make a moomba logo to replace the supra?


09-25-2010, 12:48 PM
Yes, you can get the grill and the badge and replace the two layers of vinyl on the backside with any logo or contrasting pattern of your liking. Its just a negative and positive overlay. it can't be too difficult if I thunk it up.

Earmark Marine

09-25-2010, 06:03 PM
I won'thave the box carpeted by tmr but I'll be sure to take some pics.

SWEET! Looking forward to seeing them. :D