ported box for boat and size restraints

Printed From: the12volt.com
Forum Name: Marine Electronics
Forum Discription: Boat Stereos, Security, Navigation, Lights, Switches, Gauges, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=131270
Printed Date: May 02, 2025 at 5:03 PM

Topic: ported box for boat and size restraints

Posted By: advanex
Subject: ported box for boat and size restraints
Date Posted: April 24, 2012 at 1:15 PM

My friend has a boat, and in one compartment, he has a 12" Alpine Type R in a sealed box (with many leaks and too small!)

I want to build him a ported box, but I have one issue.

The opening is 10" wide and 18" tall. I could probably fit 2' 6" to 3' long box through the opening. He wants SPL, so from what I read, ported is the way to go. Alpine recommends 1.7 cubic feet in a ported box.

Do I have enough room for a 1.7 cubic foot ported box? Can anyone show me a design that would fit this purpose?

Keep in mind that he opens the door to this opening when he plays music. This is the compartment behind the steering wheel.

I can get pictures if it will help.

Thank you.

Replies:

Posted By: advanex
Date Posted: April 24, 2012 at 3:55 PM

Here is a picture of the area I'm asking about. The red arrow is the door opening that I'm trying to get this box into. Under the dash area is pretty open and spacious behind that little door.

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Posted By: DYohn
Date Posted: April 24, 2012 at 7:07 PM

How deep is the woofer? If your enclosure is 9.5" deep and 17.5" tall, if you can make it 26" wide, using 3/4" marine plywood you'll end up with 1.8 cuft gross volume. Add the driver and a couple simple cross braces and you're right at 1.7 cuft. But will your woofer fit into something that's only 9.5" deep with 3/4" walls?

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Posted By: advanex
Date Posted: April 24, 2012 at 7:36 PM

Alpine specs say that the mounting depth is 6.375". How would I create the port and to what size?

Posted By: advanex
Date Posted: April 24, 2012 at 8:09 PM

https://support.alpine-usa.com/products/documents/OM_SWR_S06212011.pdf

Here's the spec sheet for the Alpine Type R sub. It may help determine what frequency and port size I need. Keep in mind that I'm still learning about ported enclosures and tuning them. I'm willing to read and learn.

I've built a Digital Designs box for my own ride, but it had all the dimensions already there.

I'm not sure how to calculate the proper port size once a box has been modified or re-created.

Posted By: advanex
Date Posted: May 13, 2012 at 9:05 AM

Well, I finished building it. He's amazed at how it sounds. Here's a couple of pics of it. It was a super tight fit in the boat, but it fit.
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Posted By: advanex
Date Posted: May 14, 2012 at 5:01 PM

Here's a pic of it in the boat. Sorry for the crappy quality.

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