pro-rabbit
5,000+ posts
Moderator
Since those dimensions are external and we are assuming 0.75" material thickness used throughout, the total internal size of the enclosure before the port is taken into consideration is 22.5Wx12.5Hx16.5D which gives you 2.68 ft^3 before port displacement. The port itself is 2" by 12.5" by 32.5" long by your measurements, which takes up 0.47 ft^3. The internal port wall takes up 0.12 ft^3 and the 45's are probably another 0.2 ft^3 which leaves you with right at 1.8 ft^3 tuned to 31 Hz. It's a small box tuned low that possesses an F3 of 25 Hz outside of your car...let alone when you throw in cabin gain. If that is the case your enclosure is the right size and is also tuned correctly...and it's actually tuned lower than the enclosures we have here at the shop. You should have zero problems with LFE. That's tuned lower than the 15" I have in my daily driver.
...unless I totally missed something.
However, if the port length really is 18" to 19" long then it is tuned around 39 Hz.
If you click the link I provided for the build log you can see that the port is only 18-19" long if that.
