Well the wife is driving the P5 now and she wanted the spare tire back in. So I pulled the elaborate system and installed some of the gear from her old car. A PPI 5440 5-channel amp and an Image Dynamics IDQ 10" subwoofer. The amp runs DLS Iridium components up front active (tweets and midbass, no midrange this time) and sends 200w to the subwoofer.
The enclosure I built might be a little small for a 10" but I'm guessing it is a little over 0.5 cuft.
Step 1 was to build the base out of 1/2" MDF. I would have used 3/4" but I had a piece of 1/2 and didn't want to waste it.
Step 2, I added a few layers of double-sided sticky tape to the bottom. This represents the thickness of the carpet flooring in the car. If you skip this step, your box may not fit in with the carpet in place.
Step 3, Mask off the entire piece with painters masking tape.
Step 4, fiberglass! Make sure you build it up so that it is at least 1/4" thick all around, 3/8"-1/2" preferred. You can use cloth glass to start but you need the fiberglass matte to add thickness and stiffness. I precut the matte into 4x4" squares and then mixed about 8 fl oz at a time. Grab cheap plastic painters cups with measure markings on the side so you can accurately measure resin/hardener. Put the hardener in first so it mixes as you poor the resin. If you put it in last, it will stick to your brush as you mix and you won't get a good mix...trust me on that one. That is a priceless tip.
Step 5, After the resin cures pull out your mold and remove as much painters tape as possible (I can never get it all off).
Step 6, Using marker, mark where you want to remove the glass around the edges...I always go at least 1" beyond where I am going to cut. I use a jig saw to cut the excess fiberglass off.
Step 7, Mount your baffle (sorry I didn't photograph building the baffle...it is just a ring a little wider than the subwoofer with a routed edge for stapling fleece to.
At this point in my project my digi cam stopped working. It just took black photos. Yay! But anyway.
Step 8, stretch fleece across the front of the box. Use hot glue to secure it in place around the outside...stretch it is tight as it will go, any loose sections will sag and wrinkle once you fiberglass. Use a staple gun to secure it around the baffle ring.
Step 9, add lots of fiberglass to the fleece but be very careful around the edges...any extra around the edges will have to be sanded/grinded off. Also be careful around the baffle. I designed my baffle with a 1/4" routed edge and made sure no fiberglass made it onto face of the baffle. That way I could just sand it smooth and not have to worry about a jagged mounting face for the subwoofer.
Step 10, add several layers of fiberglass matte on top of the fleece until it is at least 1/4-1/2" thick on the flat areas. Rounded portions are usually stiffer and don't need as much thickness.
Step 11, Sand off the edges with 40-60 grit and an orbital sander...or use a dremel and grinder bit. Sand smooth the face using 40-60 grit and an orbital sander...good luck if you don't have an electric sander.
Step 12, cover with carpet. That's right, if you are using carpet you don't even have to clean up the crappiness of the fiberglass face. It hides everything. If you want to paint or vinyl you've got lots more bondo and sanding to do.
And, now that you read all that, I'll grace you with some crappy camera phone pics I took last night...
It sounds pretty good. I did some initial low-volume tuning for my wife and found a crossover point of 50Hz was best at low levels while 80Hz was better for my listening levels. Below 30Hz it runs out of steam due to the small enclosure size but it is tight and there are not rattles thus far.
Total build time was about...hmm. I don't know maybe 8-12 hours including cure time. It could have been done in one very long day. I spent 4 hours on a saturday, another 3-4 on a sunday (getting the baffle to stay in place was a pain since I only had liquid nails...I'll need something stronger next time), and then another 2 hours the next weekend to sand a little and apply the carpet.
Supplies for the job...
* 1/2" or 3/4" mdf (2x4 sheet from Home Depot is enough)
* Fiberglass resin (large can)
* Fiberglass matte (3-4 packets)
* 5-10 cheapo paint brushes
* 2-3 mixing cups (with 4/8/12/16 oz markings)
* 3 rolls of painters masking tape (2 1" and 1 1/2")
* car wax (spread over tape to help mold release)
* drop cloths and clothes you don't care about
* lots of rubber gloves
* resporator (or hold your breath and work outdoors)
* 1 yard of fleece (pick your favorite pattern!)
* 1 yard of un-backed trunk liner
* 1 can of 3M Super 77 spray adhesive
* hotglue and glue gun
* staples and staple gun
* router and circle jig (or jig saw...but router is better)
* jig saw
* orbital sander with several 40-60 grit sanding discs
* sharp razor blades for cutting carpet
* drill with assorted drill bits
* 3' wooden dowl
* opt. polyfill and sound deadener
* opt. velcro to keep it from moving around