1. Goal: To make a unique instrument out of PVC Pipe
PVC Pipe Instrument
Goal: To make a unique instrument out of PVC Pipe
Jim Pepper

2. Where We Left Off… Pipes Completed Frame Needed to be Built
Objective- Portability, Easy to Assemble
Legs and Lower Frame
More PVC

3. The Finished Project Not screwed together, straps needed for support
New “mallet”- Wood with mouse pad that is looser
Playable in the same way as a xylophone

4. Off? Some lengths were off.
Note
Desired Frequency
Tube Length Estimate
Freq Ratios Length
Exact
Difference- Estimate to Exact
Ratios to Exact C
130.81 49
48.25
C#/Db
138.59
46.25 D
146.83
43.659
43.23
D#/Eb
155.56 41 E
164.81
37.75 F
174.61
36.71 36
F#/Gb
185
34.643
33.75 G
196 32
G#/Ab
207.55
31.5 A
220 28
A#/Bb
233.08
27.489
26.25 B
246.94
25.945
25.25
261.63
24.5 25
Some lengths were off.
First, the estimate from the equation (Length= /(2*Frequency) + Radius)
Second, estimate based on frequency ratios
Third, exact measurement from instrument

6. Is the Pitch Off?
Predicted Pitch
Pitch
Desired Freq.
Actual Freq.
Difference
Predicted length
Actual Length 48
48.25
130.81 49
49.1
138.59
46.25 50
50.1
146.83
43.23 51
155.56 41 52
52.05
164.81
37.75 53
53.05
174.61 36 54
185
33.75 55
196 32 56
207.55
31.5 57
57.3
220 28 58
58.1
233.08
26.25 59
58.8
246.94
25.25 60
59.85
261.63 25
Using a chromatic tuner, found each pitch difference in cents
Used the equation 440*2^((Pitch-69)/12) to get the actual frequency

7. Sound End Correction- Pipe, 2 open ends From Benson Wave Equation
Effective length longer than actual length by approx. 3/5 of tube width
-Sound coming out of it
If this were the case, each would have to be shorter
Difference is scattered, both + and -
Pipe, 2 open ends
Wave Equation
∂²p/∂²x² = 1/c²*∂²p/∂t²
Could then be cutting error

8. Conclusion
Despite slight differences in length, each pitch is still identifiable with its respective note
Full 12 note octave can be played as well as all intervals