There are dozens of how-tos for DIY phone speakers, but they all have the same basic concept: You find something curved or tubular and you place your phone inside of it. I tried a wide range of speaker DIYs to find the winners and losers. Here are the results.
This is probably the simplest DIY speaker hack I came across. All you do is put your phone into a cup or ceramic mug. The sound from my phone did get louder, but it was distorted in the mug. A plastic drinking cup and a Styrofoam cup didn't really make the music any louder, but it did make the bass sound a lot better. A cup made from glass worked the best.
Bowls worked just as wells as cups and didn't seem to distort the sound very much. Again, glass works better than plastic.
One step up in difficulty from putting your phone in a cup or bowl is sliding it into a toilet paper tube. Just cut a slot into the tube and slip your phone in. Pretty easy, huh? It does boost the volume, but on the downside it's hard to keep your phone upright.
Plastic cups and a cardboard tube
I have to say, this one worked impressively well. All you do is cut two holes into the sides of two plastic drinking cups and insert a toilet paper or paper towel tube. The sound is great and your phone stays upright. Here's a tip that most sites overlook: cut holes into the bottoms of the cups, too. The sound quality is much better.
Padded mailing envelope
Like the cardboard tube, this hack only requires a few snips with a pair of scissors. You cut the ends off of a padded mailing envelope, fold it so that it's a dome shape and put your phone inside of the dome. You may as well skip this one. It amplified the sound a little bit, but not enough to make the hack worth it.
Plastic tubes and paper tubes work, so why not an aluminum tube? Yah, no. The sharp edges of the can will injure your phone and, possibly, your hands. Also, it doesn't work. Just say no to this hack.
2-liter soda bottle
Don't bother cutting a slit in a 2-liter soda bottle and sliding your phone in. This was the worst hack I tried. Not only does it not amplify sound, it muffles it. I hacked the hack, though, and cut off both ends of the bottle. After the alteration, it worked just as well as using toilet paper tubes.
This was the best speaker hack for the least amount of effort. All you do is cut a slit in a round chip can. The sound bounces off of the metal end of the can, amplifying the sound while retaining the sound quality.
This hack looks like it would work, but it doesn't. The instructions say to cut off the ends of a cardboard box, to pinch one end and staple it together so that there is just a slot for your phone. It ends up looking a lot like a cardboard megaphone. It doesn't work like one, though. In fact, it doesn't do a darn thing. Folding it into a more curved shape doesn't help, either.
This was probably the hardest DIY speaker I tried. It is basically the same as the toilet paper tube hack, but you have to use a jigsaw instead of scissors. It was worth it! The sound quality was the best of all the DIY speakers. If you add cups to both sides, it gets even better. The sound quality is great.