PASSIVE ΠPHONE SPEAKER

Most phone amplifiers are just a hollow chamber which allows the sound to resonate, increasing the decibel level slightly but giving a deeper more satisfying sound. This one is cheap, easy to build and looks good as it utilizes one of those novelty coffee cups that we all have but never use.

My cup was 3.5” wide and 3.5” high so it has a circumference (C=πD) of 10.99 inches

A top area (A= πr2) of 5.5 square inches

A volume (V=πr2h) of 19.2 cubic inches which is significant as this acts as the echo chamber!

MATERIALS;

Novelty cup or beer mug

Jar lid to fit cup

Wood scrap

TOOLS:

Drill with step bit

Metal shears

Hot glue gun

Ruler

Marker

Half round file

Fine tooth saw.

After measuring your phone, mark the slot to fit it on the lid. Mark a straight line to keep the phone at the correct angle and follow the curve of the lid for the back rest.

On the scrap wood, mark slightly less than the width of the inside of the cup as a stop to keep your phone in position. Mark a second smaller piece to stop the phone from falling into the cup. Make sure this piece does not cover the phone’s speaker.

Drill holes in the slot then cut away the plastic with the shears. The hole should be large enough to hold the phone and have enough area to let the sound escape as well. Cut the wood to size.

File the cut edges. Glue the wood pieces in place so they sit where they can support the phone. Place the lid on the cup. Put your phone in position, turn on music and test. NOTE: You can drill a hole in the small wood piece to accommodate a charging cable if you want to charge your phone while you listen to music.