All Wound Up!
Science fair 2015-16
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
- Different strings (3)
- Red-label Super-Sensitive (steel core, steel wound)
- Thomastik Dominant (synthetic core, aluminum-wound)
- 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)
· Strings (different materials)
· Tuning of string
· Bow speed, pressure and direction
· Bow position between fingerboard and bridge
· 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.
PICTURES AND VIDEOS
ANALYSIS OF Dominant 'D' String
ANALYSIS OF SUPER-SENSITIVE 'D' STRING
ANALYSIS OF D'Addario 'D' String
We used a microphone right beside my viola to record the sound of me playing the open 'D' string.
This device converts sounds from the microphone and transfers them to the computer, where the iAnalyzer software records them.
The viola is a member of the stringed instrument family and has four strings, tuned C, G, D and A. You use a bow to draw sounds out, and you change the pitch by putting down your fingers in different places on the fingerboard.
This is a steel-core, steel-wound string.
This is a steel-core string wound with aluminum.
This is a synthetic-core string, wound with aluminum.
FREQUENCIES IN THE OVERTONE SERIES
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
E-mail 11/27/2015 from Damian Dlugolecki about string types -- http://www.damianstrings.com/
Synthetic-core strings -- https://www.johnsonstring.com/resources/choosing-strings/strings-types-synthetic-core.htm
Steel-core strings -- https://www.johnsonstring.com/resources/choosing-strings/strings-types-steel-core.htm
Frequencies of notes on a keyboard -- http://www.sengpielaudio.com/calculator-notenames.htm
Overtone frequency calculator -- http://www.sengpielaudio.com/calculator-harmonics.htm
Harmonics and Overtones -- https://en.wikipedia.org/wiki/Harmonic_series_(music)
Physics of Music and How Strings Vibrate -- http://www.phy.mtu.edu/~suits/overtone.html