nkb93
SLO 4 SHO
For those interested in upgrading the factory subwoofer to a larger aftermarket sub and reusing the factory sub box, I thought I would submit my recent experiences.
The 8" driver I bought to replace the original factory sub likes to live in a vented enclosure of roughly the same volume as the factory enclosure.
Speaker Specs:
http://www.tb-speaker.com/detail/1208_03/w8-740c.asp
I wanted to reuse the factory sub box to allow for easy mounting back in the factory location. It's also much lighter than an MDF box of the same size. The primary difficulty was figuring out how to port the factory box.
I decided to tune the box to 32 Hz, pretty low for an 8" sub. This results in using two 1.5" PVC ports, about 26" long. Obviously, a 26" long port isn't going to fit inside the box. So, at the risk of making my sub look like a plumbing project gone horribly wrong, I went with an external port instead.
Ok, so now where to point these ports? At frequencies near the box tuning frequency, a large portion of the total sound pressure comes from the ports, so I wanted to have them firing into the cabin too. After much thought, I decided to ditch the factory rear deck speakers and have one port firing up through each speaker hole. This wasn't a big sacrifice since 99% of the time I have it faded all up front on my components anyway.
Box bracing is important since the larger driver will cause the factory box walls to flex. I cut out some 3/4" MDF panels and glued them to the upper and lower faces with Liquid Nails. That combined with a few 90 degree triangle pieces of MDF glued inside the box to brace between faces makes this a very rigid box.
So, here are some pictures of the box that I built:
Top of Box, showing flared port outlets:
Bottom of box, elbowed ports
Finished box, painted with Duplicolor bedliner
When I have a chance to install and test it, I'll report on its sound quality.
Nathan
The 8" driver I bought to replace the original factory sub likes to live in a vented enclosure of roughly the same volume as the factory enclosure.
Speaker Specs:
http://www.tb-speaker.com/detail/1208_03/w8-740c.asp
I wanted to reuse the factory sub box to allow for easy mounting back in the factory location. It's also much lighter than an MDF box of the same size. The primary difficulty was figuring out how to port the factory box.
I decided to tune the box to 32 Hz, pretty low for an 8" sub. This results in using two 1.5" PVC ports, about 26" long. Obviously, a 26" long port isn't going to fit inside the box. So, at the risk of making my sub look like a plumbing project gone horribly wrong, I went with an external port instead.
Ok, so now where to point these ports? At frequencies near the box tuning frequency, a large portion of the total sound pressure comes from the ports, so I wanted to have them firing into the cabin too. After much thought, I decided to ditch the factory rear deck speakers and have one port firing up through each speaker hole. This wasn't a big sacrifice since 99% of the time I have it faded all up front on my components anyway.
Box bracing is important since the larger driver will cause the factory box walls to flex. I cut out some 3/4" MDF panels and glued them to the upper and lower faces with Liquid Nails. That combined with a few 90 degree triangle pieces of MDF glued inside the box to brace between faces makes this a very rigid box.
So, here are some pictures of the box that I built:
Top of Box, showing flared port outlets:
Bottom of box, elbowed ports
Finished box, painted with Duplicolor bedliner
When I have a chance to install and test it, I'll report on its sound quality.
Nathan
