- What: PVC Saxaphone
- Why: Hooooonnnnnnnk!
- Concepts: acoustics, waves, physics, music
- Time: 30-40 minutes to make, a lifetime to master
- Cost: ~$2
- PVC (3/4" or 1/2" works great)
- 4 PVC elbow joints
- 1 Plastic Funnel
- 1 Piece firm plastic (from packaging works great)
- Tape (heavy duty)
- Hacksaw (or PVC cutter)
- Hot glue gun and hot glue
Let the music play!
Step 1: Start Your Reed
If you've ever accidentally talked to someone who plays a woodwind instrument, you've probably heard a lot about reeds. Well now you get to experience a single-reed first hand.
Start with your PVC pipe, and draw a diagonal line. I found that around 30 degrees works well. Use a hacksaw, and give it a cut. File off a little bit of the "tall" end of the diagonal cut" so that it's slightly rounded. This will make the reed sound much easier to play.
For a look into the amazing science of reed instruments, check out this link to get started.
Step 2: Finish Your Reed
Cut out a tongue of firm plastic the size of the opening of your PVC cut. Leave a little tail on the end for taping. Tape it down hard toward the bottom of the diagonal cut, leaving the top part free. There should be a small gap between the PVC and the clear plastic. If not, file down the PVC a little more.
Now try playing your reed by simply putting it in your mouth and breathing. You may have to experiment with bite and depth for a little to find where the note is made.
For more help on making this part of your saxophone, check out my previous project, "The Most Marvelous Honk."
Step 3: Cut Your Sax
You wouldn't be inventing your own instrument if you followed every one of these instructions, so get creative. The basic PVC saxophone "shape" is to cut out four more PVC lengths in addition to the mouthpiece, and to connect them all with elbow joints. In cutting the lengths, the main pipe where finger holes will be placed is the longest.
Use a hacksaw or PVC cutter to make any wild size or shape you want. The overall length of your pipe will affect the notes played, so you can mess around with a number of length combinations.
Next, drill holes in the longest of the PVC tubes to make finger holes for playing. You can experiment with different spacing to get different harmonics, but ultimately the closer the holes exposed are to the mouthpiece, the higher the note played.
Sound Science Stuff:
The sound created inside is due to standing waves created in what is effectively a close-ended air column. For a look at the science in harmonics and close-ended wind instruments, check out this website. For a look at specifically how saxaphones work, see this primer. A significant difference in the sound of a brass sax and our PVC sax is that our column is not a conical or bowed shape, but a cylindricial one.
When you open up air holes with your fingers, you are changing the length of the wave that resonates most strongly in the tube. In a simplified way, this is similar to shortening the length of the tube to wherever the closest exposed hole to the mouthpiece is.
Step 4: Amplify
You can't keep your PVC music just to yourself. Let those goose-like tones fly!
Cut off the end of the plastic funnel, hot glue it, and stick it either inside or around the end of your saxophone to amplify your sound a bit, as well as give it a bit of an aesthetic flair.
Step 5: Release Your Coltrane
Well the music isn't going to play itself! Start your path to Carnegie Hall one plastic note at a time.
You can honk and toot the day away, and when you're ready, take it apart and make a different design. All parts are easily interchangeable, and I'm excited to see what variations you come up with.
To learn more on the physics of sound, start here and then jump in to learn more about the science of instruments.
Have fun, happy tooting, and as always, keep exploring.