Creepy Cast Concrete Mono Speaker

What inspired me?

I completed this project during my college time I finished my work about a month early. This allowed me to do what ever I wanted so I made another speaker. This speaker is just acrylic and concrete with a mono speaker and circuit in the centre.

This is my second, more simple, cast concrete speaker. This was a quick and easy practical and I completed the product within a day. Most of this time was waiting for the concrete to set as this took 20 hours. Anyway, I love the combo of modern materials with the obscure ones. The materials makes it more of a focal point.

To make this you will need;

- plywood

- acrylic

- a kitronic mono speaker circuit

- concrete

- laser cutter

- cardboard tube

- band saw, jig saw, hand saw, threat saw, tenon saw

- line bender

Step One - Making The Mould

First of all, cut four equally sized plywood pieces. You can do this with a band saw, a jig saw, hand saw or tenon saw. you can use any type off saw but a circular saw or a Band saw will probably best as the edges need to be very straight. If you are using a Tenon, make sure you use a bench hook so you can cut along the longer face for a straight edge.

When this is done, cut a fifth piece that will be the bottom panel. This piece should be the width and length of the others but added onto it the depth of the plywood you are working with. This will stop any concrete from pouring out.

Use sand paper (NOT A BELT SANDER) to get rid of any burs around the edges of the work. Using hot glue, join the pieces together to make a cube. Make sure you add a lot of glue to prevent the concrete from existing and causing the mould to break.

Step Two - Mixing The Concrete

Begin to mix water and ready mixed concrete in a small bucket, until it becomes thick but pourable. Place the cardboard tube in the centre of your work and begin to pour the concrete inside, Use a piece of dowel to make sure the corners are filled and the mixture is all around the cube. Leave to set. this may take up to 2 days depending on the water to concrete mix ratio used.

Concrete is the type of material that if you add ore of something, it changes the over all consistency, strength, colour and hardness. You can also add different materials such as paint, dye and bits of glass just to make it look less dull. Saying this I love the colour of the normal set acrylic.

Step Three - Finishing the Concrete Block

When the mixture is very hard, the colour will go lighter and the surface will be quite dusty. Use a chisel or a flat screw driver to take off the mould. This may take some time depending on the amount of glue so be careful not to rush this step as you may injure yourself or damage the concrete.

Run the cardboard tube and concrete under warm water to enable you to get the card out. soak it for a while then use a chisel to remove it.

You can now personalise the product by applying a range of finishes to the concrete to seal the surface and eliminate the dust.

Step four - Laser Cutting and Line bending

Measure the size of your block in mm using either a digital Vernier or a simple ruler. Measure the front and the top of the block when the hole is running perpendicular to the work surface as these are what you are going to cover with acrylic. Using a 2D design software, draw out the front and top as one whole piece. Increase the entire length by one centimetre to allow room to bend. Make a hole in the centre of the acrylic for the speaker. Make this 60mm in diameter. draw anything else onto the surface. it scan be cut, engraved or added at a later date. Make sure to add two little triangles onto the bottom of the first piece. This will be located at the bottom of the front piece to hold the concrete up at an angle. The triangles must be connected at the bottom and must be 10mm by 50mm.

On top of this, using a different coloured acrylic, design a speaker cover with a diameter of 60mm. This will fit inside of the hole drawn on the first piece of acrylic.

When this is done, make two small triangles, this must be adjacent 10mm and opposite 40mm.

When this is cut out via a 2d laser cutter, use the line bender to bend the acrylic where the front face meets the top face. Use the concrete as your mould and bend it over your soon to be speaker.

Step five - Attaching the Pieces

Using araldite, attach all the pieces to the concrete, allow the glue to set about 5-10 minutes before moving. follow the pictures if you need help.

Step six - The Circuit

The mono speaker circuit from kitronic comes in fully soldered. Test to see if it works before using all purpose adhesive to attach it onto the speaker cover.

https://www.kitronik.co.uk/2154-mp3-mono-amplifier...

This is the circuit I bought. its a simple, prebuilt circuit from Kitronic.

Finished!!

BOOM! You have finished. feel free to alter the designs and aesthetics as this took my 20 minutes as I finished my work early. Good luck and thank you for reading this. Please comment to tell me what you think. Please follow and favourite if you enjoyed my project. Feel free to ask any questions in the comment section. On top of this, if you have any features you think need changing, improving then feel free to comment. thank you so much for reading!