UPDATE: One of the steps didn't upload, so see the newly re-uploaded step 6 and afterthoughts in step 8
This is a simple method to make one of those Sweet Sexy Speaker cabinets that you see in all the Car magazines. This method can also be applied to speakers for your home or other mods for your car such as amplifier racks or something as mundane as a cup holder. It can be blended into your interior by colour matching paint or covering it in the same carpet materials as your cars interior. However I went with covering it in cheetah fleece fun fur and hardening it with resin.
The basic construction is to use either MDF or Plywood as a base, hollowed out for a speaker and a skeletal support structure built from the same materials. Fleece is stretched over the support frame and stapled or hot-glued in place. The it is painted “wetted” with polyester resin, sanded smooth and reinforced from inside with fibreglass matte. In the past I have made a translucent version that was backlit from inside. For the speaker rings and supports, I cut ¾” thick lexan into my desired shapes and used a combination of ¼ “ lexan sheeting and woven fiber glass cloth for all the intricate bends and flat panels. I mixed a touch of phosphor into Epoxy resin which I used to wet out the fibreglass. Inside the unit I mounted a black-light neon automotive tube. At night it glowed with an iridescent sheen that was quite spectacular, but with this sort of set up you really can’t use nice boomy speakers as it’s just not rigid enough at higher volumes.
This smaller speaker cabinet demonstrated here is going in my beater pick-up. It’s one of those old Nissan King Cabs with the fold up seats. As I still torture people from time to time by making them sit back there, I wanted a speaker unit that was small, relatively smooth and free of sharp angles. The raised spiked feet elevate it over the hump running down the center of the cab, they also dig into the carpet locking it in place. It was measured so it was held in place by the center console and the back wall. Its Surian eye port looks out over top. the downward facing subwoofer reflects base down and up, really filling the small cab of the truck. Being all smooth in nature, In the event of crash I figured I’d lessen the death trap back there by allowing their heads to collide into something smooth and round instead of a heavy MDF Square box. Ok, in reality it just looks cooler, but I digress. Follow the steps to learn how to make a simple yet sexy speaker cabinet.
Step 1: Materials
- Fleece – enough to cover your frame, I once used an old mount equipment fleece jacket. today though - CHEETAH
- MDF or good quality plywood for your base and supports
- Polyester resin, the one built is small, but the fleece was thick, used about 1.5 litres
- Woven or matte fibreglass cloth for reinforcing the structure
- Fibreglass putty “Bondo” for smoothing the final structure if painting, also useful for reinforcing fillets in the corners
- Wood screws
- Staples or hot glue
- Covering material, Mine is painted so more prep is required.
Tools n’ stuff
- Jigsaw/scroll saw
- Staple gun
- Hot glue gun
- Angle grinder with flap disc
- Silicone caulk
- Brush or roller
- something to mix your resin in
Step 2: Plan
First thing you should do is to plan it out and ask yourself some questions
• How you want it to look
• Where it will be placed
• Required internal volume for the desired speakers used
• How many speakers used
• Ported or non-ported
• How will you run the wires, will you use quick disconnects
• Do you want it easy to remove or is this a semi permanent install
Mine is being installed in the back seat area of my pick up, so.
• It will be riding over the hump running down the center of the truck.
• I also need it to allow space for people’s feet while riding in the back seat.
• However it needs to be removable when I have larger people sitting in the back seat.
• I am hooking this up to a mono amp, so will only be using one sub-woofer. This will be mounted so that it is down facing.
• The speaker cabinet itself will be resting on 3.5” steel legs. The feet of the legs will be sharpened into spikes allowing them to really bite into the existing carpeting. This also helps isolate the speaker from the car reducing tinny vibrations. And of course this allows the sound to bounce downwards reflecting off the floor and back up at different angles through the cab. This is similar to how a Bazooka base tube works by firing into a corner.
• The whole unit will have a quick connector allowing to be easily removed from the rear wall of the truck, yet still provide the occupants some piece of mind that in the event of a crash the whole unit doesn’t bounce around the cab like a psycho bowling ball of death.
• Since I want it removable I will be building it so it can operate as an external speaker, meaning I can remove it from the truck and use it as a speaker for outside entertainment.
• As I am limited on space I will be making it ported, however my port tube will have a 90 degree bend in the middle. In the past I have found this allows me a slightly smaller volume than normal. Why? I have no idea, just a happy accident. I’m sure audiophiles will be able to explain that one to me.
• Lastly, I am going to paint it, this is more work as more prep is required for a nice finish, but personally – “carpeting in a vehicle just always seemed like a bad idea.”
Once you have answered your own questions you should sketch it out. It doesn’t have to be pretty but it should act as a basic blue print.
Step 3: Base and Legs
Prep your Base
- Determine the maximum size base you can have and cut your plywood or MDF to fit.
- Center your speaker on the board and trace around it.
- Trace a smaller circle within it to provide a lip for the speaker to be bolted on too.
- Cut out the smaller center hole
- Slip the speaker into the hole to make sure it fits snugly, don’t screw it on yet.
Prep the legs
- Shave your angle supports on one end to a point, mine had holes in the tips so I decided to make 2 points.
- Place them accordingly on the bottom of the board and mark to be drilled.
- Drill out the holes and bolt in place. Use washers, lock-tite on the threads and double bolt in place
Step 4: Frame and Port
- Cut a disk of plywood 2 inches wider than the outer diameter of your port
- Cut a smaller circle in your disk of plywood just wide enough to barely squeeze in your port, you want it to be really, really tight.
- Squeeze in the port pipe and if you haven’t all ready, attach your 90 degree angle and down pipe. Don’t glue in the port though, you still need to remove it prior to skinning
- Cut out your 4 legs. The 2 rear should be matching and the 2 front should be matching. i would put a pattern but really these are swoopy shapes that were cut free hand, all you need is the height and go from there.
- Sand a smooth radius on the outer corners
- Using wood screws attach the legs to the base, then screw it to the disk.
Step 5: Skin-it
- Lay your fleece over the top, of the frame.
- Pull the fleece through the center of the disk and cut an x in the middle
- Slowly start pulling the fleece corners through the hole and sparingly hot glue in place on the back of the disk.
- Start stretching the material over the frame around and staple gun in place. Your material should extend at least 2 inches over the bottom edge of the base. Its best to center it in the middle front first and then work your way around. If you are wanting it to follow the exact radius of the plywood supports put a small bead of hot glue on the edge and press your fleece into it. Do not press to hard though as you don’t want the hot glue to penetrate the fleece all the way. Towards the back you may want to trim the excess material and hand sew it in place. Alternately you could just hot glue the seam together, reaching in through the bottom hole where the speaker will go.
- Mix up your resin as per the manufactures instructions and start painting the fabric. Lay it on pretty thick until the resin weeps through to the other side of the fabric. Apply extra along all edges, the bottom of the base wear the fabric joins the wood and in the port hole.
- Allow to cure
Step 6: Make It Stronger
Now it’s time to reinforce your structure, it may feel strong but it’s actually somewhat brittle. I am sorry there are no pictures but at this step it couldn’t be helped. I was by myself and the thought of getting resin all over my good camera trying to get some action thoughts was meant to be. I have included a bit-mapped drawing showing how the layers go together.
I started by reaching inside and filling the inner corners with a thick fillet of fibreglass putty where ever the fleece is joined to the wood. Immediately I made up a batch of resin and painted the inside of the fleece shell with it.
Kind of like doing papier-mâché, I started pressing in chunks of woven fiber glass cloth into the resin, “you could use random fiber matte as well”. Working quickly I painted another layer of resin over this and thoroughly saturated the cloth, repeating and built up several layers. These layers would over lap the frame, the cheetah skin and the fibreglass putty fillets.
With other mediums you wait for each layer to dry, with resins and putties you start applying the next layer as soon as you’re finished the first. Before you even finish the first layer your putty has all ready hardened. The resulting cured unit fuses together into one rigid structure rather than delaminating like layer cured units do.
See the drawing for details.
Step 7: Wire It Up and Enjoy!
- Wire up your speaker. I am not going to focus much on this as there are many Instructables focusing on this all ready. You can simply be like me and drill a small hole in the base to feed your wire through or install a quick speaker disconnect panel. I simply put a knot in the wire and fed it through a small hole.
- The I slipped in the speaker, drill pilot holes and screwed it in place.
- Last i added a trim ring for the port, this was simply screwed in place. For those in the know, its actually the front lens panel from a fog light that I sanded the finish off and polished.
Now go and install in your vehicle and admire your handwork both auditorally and visually
Step 8: After Thoughts
The speaker unit fit perfectly into the truck and the down facing speaker works awesome. Being fed off of my mono amp this unit works brilliantly. I added 2 lag bolts to the bottom of the unit though which I fed a tie strap through. This was then fed through two eye bolts I mount in the floor. This will keep the unit locked down when going down logging roads I frequent.
Using Fun Fur Fleece was trickier than the usual fleece I use for this sort of thing. Here are a couple things I learned along the way.
- Regular fleece conforms better to multiple concaves and convex curves then the fun fur does.
- The much thicker fleece uses much more resin in order to get a full wet down. Normally when you work with polyester resin it’s actually the glass fibers that provide the strength. You want just enough resin to wet it down. Because of the fleeces furry nature the resin to fiber content is quite wasteful and not very strong.
- Like regular fleece, there is a grain of sorts. Imagine back combing a carpet, where fibers stick up. Same with the fur only much more pronounced. This is easy to knock down with a resin soaked roller though.
All in all, this build was quite a learning experience, who knew you could resin harden fun fur. Makes me think of all my daughters stuffed animals collecting in the attic. Especially the jumbo ones won at carnivals. Come Halloween, they may get a resin coating and with a couple mods could be truly wicked. Life sized Evil My Little Pony anyone?
Finalist in the
Car Audio Challenge