All Wound Up!

Science fair 2015-16


Which type of viola string sounds brightest ?


All bowed stringed instruments have four strings. When you pull a bow across a string, the string vibrates for its whole length (whether that's an open string, or if you put your finger down to change the pitch) and the instrument's body amplifies the vibrations, making the sound you hear.

Every pitch made by an instrument is a combination of the string's frequency (how often it goes back and forth, per second), called the 'fundamental', and a number of higher pitches called overtones that vibrate at fixed intervals above the fundamental frequency.

Strings are made from different materials, so some strings' overtones sound louder than others, making them sound 'bright.'

I want to see which one sounds brightest.


I think the steel-wound string will sound the brightest because it is a harder metal, so it would make a louder and brighter sound.


  • Viola and bow
  • tuner
  • Different strings (3)

  1. Red-label Super-Sensitive (steel core, steel wound)
  2. Thomastik Dominant (synthetic core, aluminum-wound)
  3. D’Addario Prelude (steel core, aluminum-wound)

  • Digital audio recorder software and hardware (iAnalyzer software, EASERA Gateway hardware)
  • Microphone, stand and cable (RODE NT-1A microphone)
  • pencil
  • notebook


Independent Variables

· Strings (different materials)

Controlled Variables

· Tuning of string

· Bow speed, pressure and direction

· Bow position between fingerboard and bridge

Dependent Variables

· Brightness of sound


1. Set up microphone on microphone stand

2. Attach microphone cable to microphone and interface

3. Launch the iAnalyzer application

4. Write down what kind of string we’re testing in journal

5. Tune the D string using tuner

6. Position bow ½” away from bridge

7. Start analyzer software recording

8. Play five down-bows, using the same speed, pressure and location string

9. Stop software recording

10. Look at waveforms and make note in journal of how the overtones look

11. Change string on viola

12. Repeat steps 4 through 11 for each tested string

13. Compare waveforms and make conclusions


My hypothesis was incorrect. I thought the steel-core was going to sound the brightest, but it was the aluminum-wound steel (D'Addario) string that sounded brightest. Apparently, aluminum makes a brighter sound than steel. Maybe the aluminum isn't wound as tight and it doesn't dampen the sound. But if that was the case, the winding would loosen as you played it. Maybe it's just the softer metal.


ANALYSIS OF Dominant 'D' String

The Dominant D string has a synthetic core made of "perlon" and is wound with aluminum.


The Super-Sensitive string is made from a steel wire core and it's wrapped with stainless steel as well.

ANALYSIS OF D'Addario 'D' String

The D'Addario string is wound with aluminum and has a steel core. If you watch the higher frequencies' peaks in the analysis, you'll see that they're more powerful (higher decibels) than in the other two strings' analyses.



Big image
Big image


Decibel (dB) -- unit of measure for volume

Frequency -- the number of times, per second, that something happens. Musical pitches vibrate at a certain frequency, i.e. "middle C" on a piano vibrates 261 times per second.

Frequency Analyzer – type of device that analyzes any sound that goes into the microphone and displays graphs of frequencies (Hz) vs volume (dB)

Fundamental -- the frequency that a string vibrates at, through its whole length.

Hertz (Hz) -- unit of measure for frequency

Microphone -- a device that picks up acoustic sounds. It can be used for recording, or for amplification.

Octave – the pitch you get if you double its frequency. Example: If an “A” is 440 Hz and you double it (880 Hz), you’ll get an octave higher.

Overtones – any sound that is higher than the fundamental frequency of a tone