Minimalist Phone Amplifier

Introduction: Minimalist Phone Amplifier

About: Architecture Student, Artist and All-round designer. :)

Hi, Kashyap here!

I've been watching quite a few youtube videos and always admired how people could make phone amplifiers out of various items such as styrofoam cups, toilet paper rolls, cardboard boxes etc. And while these are great in the short term, I wanted to design something that would last longer, and custom-designed for my old Lumia 640 LTE phone. So here it is!

The instructable is for making a passive phone amplifier that essentially 'reflects' the sound from phones with rear-mounted speakers while at the same time amplifying the sound in one direction. This, in my case (as I used plywood) gave me a bit more mid-range sound and low-end (bass) sound. But you are free to experiment with other materials. I tried plastic and it gave quite a rounded sound to music.

The other reason I wanted this is to allow me to read my notifications while playing music or see who is calling.

Hope you like it! :)


A 1/4 inch plywood piece measuring 18 by 10 inches,
Hand saw,
Wood glue,
Masking Tape,
Sandpaper (120 grit, 240 grit),
Clear spray on varnish or paste wax (to your preference),

Step 1: Cutting and Assembling

Using a pencil, mark the lines indicated in the drawing on to the plywood sheet and then use the handsaw to cut along the lines. Placing masking tape on the underside of the plywood will reduce any tearout, but just in case, do go slow to get a cleaner cut.

Next is to sand the rough edges in a miter and then using wood glue and masking tape, stick the three triangular pieces together to form a pyramid as shown.

Step 2: Notch-time

Once tightly bound together with the masking tape, use the saw to cut a notch about 1/2 inch wide into the edge of the pyramid, about 1 inch from the end. Work carefully to avoid any injury, have a friend help you if needed.

Then slot in your phone to test until the speaker hole comfortably rests inside the pyramid. Once achieved, place the two 1/2 inch plywood sticks in a right angle inside the pyramid with glue at the tip.

Give it about 15min to bond properly, and then gently remove all tape and apply your finish. I chose to leave mine unvarnished as I plan on painting it later with glow-in-dark pigments which havent arrived yet.

Step 3: Beauty Shots

Once the paste wax/spray varnish has dried, place your phone in the slot and play away with your best music mixes!


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