Conclusions from last weeks experiments

1
Conclusions from last weeks experiments

• Frequency range of Sainsburys beer bottle
• Predicted approx 282Hz 707Hz (D4 E5)
• (210ml of water hence 40ml air volume)
• Measured _at_ 285Hz 679Hz (D4 E5)

2
Dynamic range

• Results quite variable
• Measured at 1 metre A weighted
• _at_ 285Hz pp 70dB ff 92dB
• Dynamic range _at_ 285Hz 22dB
• _at_ 679Hz pp 65dB - ff 86dB
• Dynamic range _at_ 679Hz 21dB

3
Spectral analysis empty bottle
4
Analysis empty bottle
5
Spectral analysis full bottle
6
Analysis full bottle 210ml h20
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envelope
Decay
Sustain
Attack
release
8
Directional properties
80dB
77dB
77dB
73dB
73dB
67dB
9
Directional properties
78dB
78dB
80dB
72dB
10
Violin
11

• Named for the Italian Violino or small Viola
• Instrument was invented in northern Italy in the
  16th century.
• The violin was perfected over the next 150 years.
• Little changed in over 350 years

12
Construction of a violin

• Approx 60cm long (modern)
• four strings G3,D4,A4,E5 (catgut, lamb gut
  wrapped with aluminium, wire wound steel)
• Front and back plates (Spruce or sycamore)
• tailpiece and fingerboard (ebony)

13

• sides or ribs (maple)
• 8Kg downforce on bridge
• tuning pegs
• bridge positioned high above top plate
• hourglass shape
• 22Kg force end to end
• sound post and bass bar

14
Motion of the bow and string
15
Waveform of A5 from violin
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Typical spectral analysis A5 from Violin
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Dynamic range of a Violin
18
Directional sensitivity of the Violin