I've got a 1932 Ford roadster street rod under construction right now and I am trying to figure out a design for the audio system well before it is time to paint the car and have an interior installed. One of the many challenges I face involves subwoofer enclosure design and location.
The attached photos show the trunk and interior space of a car with a body identical to mine. The car has a convertible top that folds down and is stashed behind the seat. A flip up body panel covers the top when it is in the down position. There is no real space between the top and the floorpan when the top is folded down and stashed. With all of this in mind, it becomes pretty obvious that the only viable location(s) for the subwoofer exist in the trunk. The trunk space, however, is small like just about every other space in the car. What is not shown in the raw trunk photos is the 16gal. gas tank which will occupy the space right behind the bulkhead between the convertible top well and the trunk.
I should probably back up before I go any further and explain what my expectations and plans are regarding the system for this car: In another forum post I've explained what I'm lookin' to do as far as a head unit goes so I won't repeat that here / I would like to be able to incorporate a pair of 6.5" speakers into custom fiberglass kick panels / a pair of 10" subs in the trunk and a 300watt amp to power everything. I fully realize that this is WAY less than an ideal environment for an audio system. Between the wind noise inherent to a convertible and the 450hp Chevy small block rumble, I'm dealing with alot of things that are working against sound quality. When it comes to the bass response and the subwoofer sound quality, I'm more in favor of a tighter bass response - not so much boom. All that I've read on these forums very clearly suggests that I should look to a sealed enclosure. That fact that I've got very little space also would suggest a sealed enclosure solution.
Ideally, what I would like to do is to be able to create subwoofer enclosures that would perfectly fit the space in each of the quarter panels in the trunk. This is where I start to get lost.
First of all, I'm not sure how I could go about creating such a thing. Would the enclosure be made of fiberglass which would allow me to make something that fits the contours of the space exactly? (BTW- I've got plenty of fiberglass experience so I'm not sweatin' that route if I need to go that way). Would the bulkhead require open spaces to allow the sound to travel into the interior? I understand the importance of creating the proper volume of an enclosure based on manufacter's woofer data as well as enclosure design but how does one go about determining the volume for such an odd shape? Determining the volume after it's built I can figure out by filling the enclosure with some type of material and measuring how much it takes to fill but that isn't much help on the front end when you're trying to design it right.
I realize that these are all n00b questions but I could really use the advice. As I've seen in many other posts, there is absolutely no shortage of creativity out there and my car's limitations are probably similar to other install challenges fabricators have faced. I greatly appreciate any help that is sent my way.