The 3D Skull Surround Sound System (3/8" Jack)

Introduction: The 3D Skull Surround Sound System (3/8" Jack)

About: Husband Father Teacher Scholar

The Story:

The Skull System was designed on a whim. I am a Technology teacher (Woodshop, Computers, Robotics, Metal Fab., etc.) so I am always looking for creative things to build, either with students or for my own satisfaction. The Skull System (3/8" Jack Surround Sound System) was born after I made the skull. I found the picture of the skull with headphones while looking for a new skateboard graphic (long board project I do with students). As so as I was finished with the skull I knew it was destined for more I just didn't know what. A couple days later it hit me. The skull has headphones on, why not make them functional speakers?! I obviously realized that the 3/4" pine I used would not be think enough for two speakers. I then came up with the idea to make it a 3D with plexi-glass of different thicknesses and sizes which not only gives the skull shape and depth but it allows you to see through and view the graphic I worked on. I didn't want a small box to hold the electronics so I kept them plexi-glass idea and built an over-sized box with plexi-glass sides to view all the electronics. After it was built and assembled I knew I could do more and make it even cooler. After playing music from and it noticing that sound is only projected from sides from the speaker orientation it dawned on me... Let's put a pair of variable speakers in the front too! Hell, I might as well line the inside with L.E.D.s to pulse to the bass!

The ending result is a hand drawn and painted skull with plexi-glass sides fitted with 3" speakers to make it 3D. It sits atop a plexi-glass box to house all the electronics and is lined with red L.E.D.s to pulse to the bass. A pair of speakers are mounted to the front for forward facing sound as well. Each pair of speakers has its own volume control to tune your music according to the space you are in. The Skull system is equipped with a 3/8" jack to plug in your audio source.

Step 1: The Picture and Design

The first step is to print the picture to the size you want your skull to be. I have included the picture file. Once that is done cut out the skull along the pictures outline. Place the cut out on the wood you will be using and trace. I used 3/4" pine because that is what we have an abundance of in the shop, plus it smooth and easy to sand and paint. Then cut out your outline using the saw of your choice, I used a band-saw. Sand you cut out and edges lightly with 220 grit sandpaper or higher.

Begin to draw your skull. If you are not too good at drawing you could always pick up some carbon paper to help trace the image. Once the image is drawn proceed to trace your pencil lines with a medium point black sharpie. We do this because not only does it help you see the outline better but it also helps clog the wood so the paint doesn't spread and seep so easily.

Begin to paint your skull. My paint of choice was sharpie oil based paint pens. They are good quality and the paint lasts since it is oil based. **Important - Let the paint dry over night! I know, I know, it look amazing! You just want to finish it. Be patient. The end result is worth it! Now that your paint is dry, outline with a medium point sharpie again to make all of your lines crisp again.

Marvel at its beauty!

Step 2: Plexi-Glass Sizing and Cutting

I used 1/4" plexi-glass for the middle pieces and 1/8" for the outer pieces. To make these I printed out two more skull pictures. Each print out a little smaller than the other. The 1/8" plexi will get the smaller picture. Cut out the skull outlines again for each picture.

**Important - Leave all protective coatings on the plexi-glass!

Tape one side of the plexi with heavy masking tape or painters tape. NO DUCT TAPE! You need a low tack tape. The tape should cover a big enough portion of the plexi to trace the four additional skull cut outs. We use the masking tape to protect the plexi from snapping, chipping, breaking, etc. Low tack is necessary because when cutting the plexi-glass it gets extremely hot and melts. This in turn melts the glue on the tape and makes it a real pain to clean of the plexi. Trace the skull cut outs on the taped portion of the plexi with a medium point sharpie. Trace twice for each picture size (one for each side).

Cut out your plexi outlines. I used my band-saw again.

**Important - Patience!! Go slow! if you try to beast mode it it will mostly likely snap, melt to fast and you will have blade stick or just reseal what you just cut.

Once the plexi outlines are cut take an x-acto knife cut/snap off any stuck and melted edges.

**Important - BE EXTREMELY CAREFUL! always cut away from you. Avoid using your nails to pick off the edges. There is a strong possibility that an edge will go under your fingernail and believe me it hurts like a motha &*^*%$.

Step 3: Cutting the Speaker Holes and Mounts for the Outer Skull

Lay the smallest cutout (In my case the 1/8" plexi-glass) on a piece of thick scrap wood. I used 3/4" plywood because it is strong and able to hold screws well. Take your speaker and place it woofer down on the plexi and mark the holes.

Drill holes to be the same size as the bolts you will be using to hold the speakers in place. If you desire to use screws, drill a hole a 1/16" less than the screw size. I recommend using fine thread screws (Less chance the plexi will crack).

**Important - Make sure the speaker terminals are facing down toward the electronics box.

Place the piece of plexi with the holes on top of the piece of same size with out the holes and mark the holes. This ensures that your speakers will be mounted the same exactly way just on opposite sides.

Drill the holes on the other opposite side cut out.

Stack the pieces again and place back on the scrap wood. Screw down the two cutouts with fine thread drywall screws through the speaker bolt holes to the plywood. This is to ensure that the pieces won't move when you cut the speaker hole as well as making the pieces exactly match. Plus you do double the drilling in one shot :).

I used a drill press with a 2 3/4" holesaw to cut out my speaker holes.

**Important - Make sure the plywood is clamped down tight to prevent shifting. Go Slow! or the plexi will crack! Use a lubricant such as WD-40 or Nuts Off to help drill.

Once the holes are cut wipe off any excess lube and admire your work!

Step 4: Assembly of the 3D Skull

To assemble the 3D skull I used 3/8" wood dowels and a couple of wedge screws.

First install the speaker in one of the sides. From there you can see where you have room and the location of the hole for the dowel.

Mark the places with a sharpie and drill the width of the wedge screw you are using. Repeat this process for the amount of dowels you are using (In my case three).

Use the same technique as in step three. Overlay the cutouts and mark the new holes on the other cutout with a sharpie and drill.

We are again going to repeat this process except this time we will put the smaller cutout on top on the larger plexi cutout and drill with a 3/8" bit. Position the smaller cutout where you want it to go (I centered mine to feel like an actual skull where it gets smaller as you get away from the center). Mark the holes for the dowels and drill with your 3/8" bit. The wooden dowels will go through the wooden and large plexi skulls.

Lets repeat the process again except this time it will be the large plexi cut out on top of the wooden skull. Mark the holes and drill with your 3/8" bit.

Once all of your holes are drilled, take the small plexi cutouts and use a countersink bit for the holes where the wedge screws will be going. This is so the screws lay flush with the plexi.

**Important - When countersinking the holes be sure to countersink on the opposite side on the second small plexi cutout.

To assemble place the wooden dowels through each hole in the wooden skull. Then take the large plexi cutouts and slide them on both sides. Stand the partially assembled skull on its side and install one side of the small plexi skull. Screw the wedge screws in SLOWLY. DO NOT overtighten! The plexi will crack easily.

**Important - I drilled small pilot holes for the wedge screws to reduce cracking of the wooden dowels.

Marvel at your new 3D Skull! You can stop here and just keep your Brand New Beautiful 3D Skull or move on to make a bada$$ sound system.

Step 5: Electronics Box

The electronics box is fairly simple and straight forward. I cut my box to be just a little bigger than the skull itself. I used 3/4" plywood for the top and bottom and 1/4" plexi-glass for the sides.

Once your plywood is cut to size. Use a router to create a 1/4" rabbet edge along all four sides of the pieces of plywood. This is for the 1/4" plexi to sit in so everything is nice and flush.

The plexi-glass sides are going to be the same width but different lengths. This is for overlap in the corners. One piece of plexi will be a 1/2" shorter than the other.

Once all of your plexi has been cut we can assemble the plexi part of the box. I used the same wedge screws for the plexi box assembly as I did for the skull assembly. Mark 3-4 holes 1/8" in from the edge of your longer pieces of plexi-glass on both sides. Take the same drill bit you used before and drill your holes for the wedge screws and countersink. Now comes the tricky part. place the longer plexi side over the shorter plexi side to create your corner. Mark the holes with a fine point sharpie. Once all of your holes are marked we can drill our pilot holes.

**Important - For the plexi pilot holes you have to use a drill bit that is 1/16" smaller than the one you used for the initial hole that are countersunk. This is to ensure that the screws still have some plexi to grab on to.

To drill the pilot holes I used my drill press with a custom jig I made to keep it in place. Keep in mind to only drill as deep as the depth of the screws you are using.

Once all holes are drilled and countersunk grab some clear silicone to seal the corner joints (optional). I am a using silicone just as an adding layer of bonding. Place a thin bead of silicone along the edge of the plexi-glass. Screw in your screws SLOWLY and assemble one corner at a time.

Time to see if your box fits together the way it should!

Once the box fits perfect you will need a 1" wooden dowel for the center post. This post not only acts as support but also as the backbone of the box where the plywood is screwed to creating a perfect pressure fit for the plexi-glass sides.

Cut the 1" wooden dowel to the height as your plexi-glass sides, minus 1/2" (accounting for the 1/4" rabbet joint on the plywood. Drill a pilot hole in the center of each end of the wooden dowel.

Next, find the center of both pieces of the plywood. Simply draw an "X" using a ruler and going corner to corner. Drill another pilot hole. (I used 1 1/2" wedge screws for this assembly). Screw in the dowel to one side of the plywood. Place and fit the plexi box on the plywood with the dowel. Place and fit the other piece of plywood and screw in.

Done! You now have your electronics box! Go ahead and paint or stain that badboy!

Step 6: Mounting Electronics and Connections

Please use the wiring diagram I have attached for all of your connections.

**Important - I recommend soldering every connection as well as using hit shrink to protect it. If you do not have these available electrical tape and various connectors will work.

This is where every ones system will vary a little. It all depends what speakers you have taken a part and used for your project. Typical computer computer speakers components with a transformer power source will take up about a 2" x 5" space in your electronics box. If you are using a more powerful system from a boom box or something similar, it will take up a more significant amount of space.

The first thing you need to do is figure out where you want to mount it and mark the mounting holes as well as the holes for the power and auxiliary cord to go through. If your speaker came with a headphone jack you may include a hole for that as well. Where ever you decide to mount the electronics keep in mind the way the wires will travel, be connected and exit the box.

I mounted mine to a corner of the box where I could easily have access to any connection i needed as well as wire exit.

Step 7: Front Speaker Creation and Mounting

This is pretty straight forward. I took a second pair of computer speakers that were USB powered and connected them together with a couple of screws. You can use what ever pair of speakers you want whether they are USB or transformer powered.

If they are USB powered they will be combined with the L.E.D. transformer. If they are transformer powered they will just be wired in with the other plug. One plug will be cut off and tapped into the other.

To combine the two speakers I took apart the housing on both and situated them the way I wanted them. I my case i connected them bottom to bottom. I used hot glue where the speakers were combined as well as screws. I then put the housings back on.

Now that your speakers are combined it is time to place them where you want to mount them. I connected mine through the front plexi-glass. I held up the speakers on the plexi and mark the connection point with a sharpie on the inside of plexi. Once your connection points have been marked drill a pilot hole for your screws. I used wedge screws once again. Make sure you countersink your holes when using wedge screws. Next you will mark where your cords (power, 3/8" jack) will come through. Drill a hole just big slightly bigger then the cord. Put the cords through the hole and the attach the speakers with your screws.

Your front speakers are attached! Paint those bad boys!

Step 8: L.E.D.s and Front Speaker Connection

Please use the wiring diagram I have attached for all of your connections.

**Important - I recommend soldering every connection as well as using hit shrink to protect it. If you do not have these available electrical tape and various connectors will work.

Depending on the type of speakers used your connection will vary a little.

Obviously for this part you will need L.E.D.s. To connect the L.E.D.s you will need a a transformer with an adaptor for the L.E.D. strip. I also put in a switch to turn the L.E.D.s on and off. A simple 2 position toggle switch will be fine. Photos are attached along with links to buy. I highly suggest They have absolutely everything you need. You will also need a TIP31 transistor in order to make the L.E.D.s pulse to the music. This can be bought online or at a store like Radio Shack.


To connect the TIP31 make sure the lettering is facing up and the mounting bracketing is flush / flat with the wood. The left prong of the TIP31 will connect to either the Left or Right Input of the 3/8" jack. The middle prong will be connected to Negative of the L.E.D.s. The right prong will be connected to the Ground (shielding) of the 3/8" jack.

Amazon (TIP31) -

L.E.D. / USB Adapter:

The L.E.D.s and USB Power will be connected to this adapter which goes to the transformer to be plugged into a wall outlet. The adaptor has + & - marks for ease of connection.

Amazon (Adapter) -

Amazon (L.E.D.s) -

Toggle Switch:

The toggle switch will be spliced on the positive wire of the L.E.D.. This will disrupt the power going to the L.E.D.s.

Amazon (Mini 2 Postion Toggle Switch) -

Step 9: Testing!

Plug everything in, cross your fingers and hopefully start rockin' out!

Attached is a video of my finished 3D Skull Surround Sound System.

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    3 Discussions

    PXiF Designs
    PXiF Designs

    5 years ago on Introduction

    This is my first Instructable. Let me know how I did! Please vote for me in the DIY Audio Contest. Thanks for viewing! PS- Wiring diagrams are coming...


    5 years ago

    Hey dude.. It looks awesome ?