Instruments

PIRA classification 3D

3D20. Resonance in Strings

3D22. Stringed Instruments

3D30. Resonance Cavities

3D30.10 vertical resonance tube Draw a glass tube out of a water bath while holding a tuning fork over one end. 3D30.10 veritcal resonance tube The length of a glass tube is varied by pulling it out of a water reservoir. A tuning fork is used as a frequency source. 3D30.10 vertical resonance tube modification Design of a clamp to hold the tuning fork and resonance tube, and a bracket for the water reservoir. 3D30.10 vertical resonance tube A glass tube is drawn out of a water bath while holding a tuning fork over one end. 3D30.10 vertical resonance tube Use a tuning fork to excite the air column in a vertical tube as it is pulled out of a water bath. 3D30.11 vertical resonance tube Blow across the mouth of bottles or a adjustable air column. 3D30.12 vertical resonance tube A vertical tube is mounted over a siren disk. 3D30.14 open tube resonance A length of open tube adjusted by a paper extension and excited by a tuning fork. 3D30.15 resonance tube with piston Mount a microphone on a piston that slides in a glass tube and close the other end of the tube with a speaker. 3D30.16 horizontal resonance tube A plunger on a rod is used to change the effective length of a horizontal glass tube as a tuning fork supplies the exciting frequency. 3D30.16 organ pipe velocity nodes Lower a ring with a membrane and sand into a pipe with a clear side to observe velocity nodes and antinodes. 3D30.17 modes of a bottle A thorough discussion of modes of various bottles working up to a 3-D model. 3D30.19 low frequency generator A special tip for an air jet that produces many frequencies of low intensity useful for exciting enclosed air columns. 3D30.20 open and closed tubes 256/512 3D30.20 resonance tube 256/512 A tube is cut to length to resonate at 256 Hz when closed and 512 Hz when open. 3D30.21 conical pipes Corrections for the effective length of open and closed circular pipes are given. A conical pipe discussion with several interesting demonstrations is listed. 3D30.35 bloogles/kroogah tubes 3D30.35 Hummer tube The complete explanation on singing corrugated pipes. 3D30.35 freq tube dash pot A freq tube is attached to coffee can moved up and down in a pail of water. 3D30.35 freq tube Open tubes of corrugated plastic are whirled around. 3D30.40 Helmholtz resonators A set of spherical resonators made of spun brass. 3D30.40 Helmholtz resonators A small vane is rotated when placed near the small opening of a resonating Helmholtz cavity. 3D30.40 acoustic resonator This picture appears to be of a Helmholtz resonator. 3D30.40 Helmholtz resonators Two resonators are matched to two tuning forks. 3D30.41 tuning a resonance box The hole size of a resonance box is adjusted to maximize resonance with a tuning fork. 3D30.43 Fizeau resonance box A toothed wheel is used to produce a high pitched sound and an adjustable resonance box with a sensitive flame detector is used to determine speed of sound. 3D30.45 ploop tubes Stoppers are removed from a set of tubes of varying length. 3D30.45 ploop tubes Pull stoppers out of test tubes filled with water to different depths. 3D30.50 Ruben's tube The standard Reuben's tube. 3D30.50 Ruben's tube A gas filled tube with flames from a row of holes along the top and a speaker at one end. 3D30.50 Ruben's tube Directions for building a Ruben's tube. Picture, Diagrams. 3D30.50 Ruben's tube Drill a line of holes along a downspout and drive one end with a loudspeaker and introduce gas in the other. Flames indicate nodes and antinodes. 3D30.50 Ruben's tube A horn driver is used as a sound source. 3D30.55 Rubens tube comment A comment on AJP 53,1110 (1985). 3D30.55 Rubens tube flame structure An examination of the structure of the flames in the normal mode (flame maxima at pressure nodes). 3D30.55 Ruben's tube nodes The pressure is measured at each flame hole and the results are that the flames are larger at the pressure antinodes. 3D30.55 Ruben's tube nodes A comment on a note that the tube can be operated with flame maxima at either pressure node or pressure antinode. 3D30.60 Kundt's tube Sawdust in a tube makes piles when driven by rubbing a rod attached to a disc. 3D30.60 Kundt's tube Standard Kundt's tube: glass tube with cork dust, stroke a rod to excite air in tube. 3D30.60 Kundt's tube Stroke a rod to excite cork dust in a tube. 3D30.61 horn driven Kundt tube Investigation of striations in an electrically driven Kundt tube. 3D30.61 Kundt's tube The cork dust in Kundt's tube is excited by a horn driver. 3D30.62 Kundt's tube A variation of Kundt's tube with an organ pipe made with one side of rubber or cellophane and sprinkled with sand while laid on its side. 3D30.63 Kundt's tube on the overhead A Kundt's tube is modified for use on the overhead projector. 3D30.64 evacuate Kundt's tube Show the effect of pressure variation on the speed of sound by partially evacuating the Kundt's tube. 3D30.65 hot wire Kundt's tube Cooling of a glowing wire down the center of a tube indicates standing waves. 3D30.65 horizontal resonance tube - wire A nichrome wire stretched down the middle of a glass tube and heated electrically will glow to show standing waves. 3D30.65 hot wire pipe Blow a whistle at one end of a tube with a hot wire running down the axis to show areas of low and high luminosity. 3D30.66 Kundt's tube - impedence measurement Use the oscilloscope to show variation of impedance in the driving coil with changes in tube length. 3D30.69 pressure distribution in a cavity Liquid deformation on the bottom of an acoustic cavity shows the time-dependent pressure distribution in a standing sound wave. 3D30.70 hoot tubes A bunsen burner heats a screen in the bottom of a large open vertical tube. 3D30.70 hoot tubes Large glass tubes sound when a wire mesh at one end is heated with a Bunsen burner. 3D30.70 hoot tubes A Bunsen burner heats a screen in the bottom of a large open tube. 3D30.70 hoot tubes Singing tubes excited by hot gauze. 3D30.70 hoot tubes Hints for making a singing tube work with only flame excitation. 3D30.70 singing pipes Two metal tubes and a glass one. 3D30.71 hoot tube Insert a fisher burner in a tube. 3D30.72 hoot tubes The gauze in a hoot tube is held at the bottom of the tube and the flame is lit above it. 3D30.73 Rijke Tube - electrical heating Construction of electrically heated Rijke tubes, tuning a T shaped tube. 3D30.74 variable hoot tubes 3D30.75 Knipp tubes Knipp tubes are a special form of singing tube made by holding a short length of glass tube in the closed end of a larger tube. Picture. Ref. F.R.Watson, "Sound"p.214. 3D30.77 hot chocolate effect Tap on a tall cylinder full of water and then repeat with hot water so there are lots of bubbles. The pitch descends three octaves and rises as the bubbles float up. 3D30.77 hot chocolate effect - comment A few explanations from a physical chemist. 3D30.77 hot chocolate effect Tap on the bottom of an empty glass, a full glass (higher pitch), and a glass full of tiny bubbles (pitch raises as glass clears. Methods of generating bubbles with beer and hot water. More.

• 3D30.35 [:Corrugaphone:Corrugaphone]

• 3D30.60 [:KundtsTube:Kundt's Tube]

3D32. Air Column Instruments

3D32.10 tin flute Open and close holes on a tin flute to find pressure nodes and antinodes. 3D32.10 organ pipes with holes Show open and closed pipes of various lengths and one with holes bored in the side to give the diatonic scale. 3D32.10 resonance tubes (three lengths) Blow air out of a flat nozzle across a set of three different length tubes. 3D32.13 shrieker Insert a 1/2" dia. tube 12" long into a bottle of water and blow across. 3D32.15 slide whistle Use a high quality sliding whistle made for band. 3D32.15 variable pitch whistle A whistle with a sliding piston. 3D32.15 slide whistle The variable length organ pipe. 3D32.16 bird call Directions for making a bird call. Diagram. 3D32.20 organ pipes with holes 3D32.25 open and closed end pipes 3D32.25 organ pipes A collection of open, closed, and variable length organ pipes. 3D32.25 organ pipe A set of square wood organ pipes with a removable plug. 3D32.25 pipes and whistles A simple discussion listing organ pipes and whistles. 3D32.25 open and closed tubes Some very nice adjustable open and closed resonance tubes. 3D32.25 organ pipe An organ pipe is connected to the house air. 3D32.25 open and closed end pipes Three organ pipes, open and closed. 3D32.27 "C" bazooka A 1.314 m brass tube sounds the note "C" when blown with the lips. 3D32.30 slide whistle 3D32.35 demonstration trumpet Interchangeable mouthpiece, leadpipe, cylindrical section, and bell allow one to show the function of the various parts of the brass instruments. 3D32.36 hose in the bell With a garden hose in the bell of a trombone (flush with the end), the tones are: 3:5:7:9:11 and without the hose: 2:3:4:5:6. 3D32.40 demonstration trumpet 3D32.40 PVC instruments, etc. Very good instructions on making various instruments out of PVC. Also using a computer with a synthesizer to study scales.

3D40. Resonance in Plates, Bars, Solids

3D40.10 glockenspiel A small xylophone can be played to demonstrate the musical scale. 3D40.10 xylophone A small xylophone. 3D40.10 xylophone bars Use a microphone and oscilloscope to display the waveforms of various notes on a xylophone. 3D40.11 rectangular bar oscillations Strike a three foot rectangular bar on different faces and on the end. Listen to the different frequencies. 3D40.12 high frequency metal bars Hold a metal rod at the midpoint and strike at the end. Two rods an octave apart are shown. 3D40.15 musical sticks A set of wood sticks play a major scale when dropped on the lecture table. 3D40.15 musical sticks A set of wood sticks is cut so they sound the musical scale when dropped. 3D40.15 musical sticks Directions for making musical sticks. 3D40.15 musical sticks A set of sticks give a complete scale when dropped. 3D40.16 musical nails 3D40.20 singing rod Hold a long aluminum rod at the midpoint and stroke with rosened fingers. 3D40.20 singing rod A long aluminum rod will sing when held at the center and stroked with a rosin coated leather. 3D40.20 singing rods Hold a long aluminum rod at the midpoint and stroke with rosined fingers. 3D40.21 singing rod Stroke a 1/2" x 72" aluminum rod while holding at nodes to produce different harmonics. 3D40.23 bow the vertical rod A long thin rod attached to a short thick rod clamped vertically is bowed and plucked while held at various positions. 3D40.24 regenerative feedback in rod A detector at one end, speaker at the other, and an amplifier in between provides a regenerative feedback system for exciting a rod in the fundamental frequency. 3D40.24 speed of sound in a rod Stroke a loud rod to get a squeal, tune a oscillator and speaker to get rid of beats, and calculate the velocity. 3D40.24 speed of sound in a metal wire Wire is stretched tightly and stroked with a wet sponge. 3D40.24 velocity of sound in a rod A rod clamped in the middle is excited by a coil at one end tuned until a Lissajous pattern is formed on an oscilloscope with the signal from a microphone placed at the other end. 3D40.24 singing rod A rod is excited electromagnetically at one end and the motion is detected in the same manner at the other end for quantitative studies. 3D40.27 singing rod Find Young's modulus by finding the sag in a rod and then compare the frequency of the fundamental mode with theory. 3D40.30 Chladni plate Strike or bow a horizontal metal plate covered with sand while touching the edge at various nodal points. 3D40.30 Chladni plate A brass plate clamped horizontally in the center is bowed while the edges are touched to provide user selected nodes. Banding sand shows patterns of oscillations. 3D40.30 Chladni plates Bow the Chladni plate while damping at node locations with a finger. 3D40.30 Chladni plates Excite the Chladni plates with a cello bow. Picture. 3D40.30 Chladni plate A horizontal metal plate covered with sand is struck or bowed while touching the edge at various nodal points. 3D40.30 Chladni plates Bow circular and square Chladni plates. 3D40.30 Chladni plates A plate is driven by magnetostriction in the 10 to 30 Khz range. 3D40.31 Chladni plates Sprinkled sand shows standing waves on a circular metal plate driven at the center by an oscillator. 3D40.31 Chladni plates Drive a Chladni plate from the center. 3D40.32 Chladni plates on the OH Directions for making a loudspeaker driven Chladni plate for the overhead projector. 3D40.32 Chladni plates Chladni plates are driven from above by a loudspeaker. Pictures. 3D40.33 thick Chladni plate A circular disc of 1/2" aluminum exhibits a single pattern. 3D40.34 Chladni plates After some interesting historical and general comments, nonflat plates (cymbals, gongs, etc.) are examined. 3D40.35 2-D flame table Two-dimensional rectangular and circular flame tables, extensions of the one-dimensional Rubens tube, are shown in some lower order modes 3D40.35 flaming birthday cake Flames from a two dimensional array driven by a speaker show many resonant modes. 3D40.36 2D flame table analysis An analysis of the two dimensional flame table. 3D40.40 Chladni figures - tympani head Drive a timpani head with a loudspeaker. 3D40.40 standing waves on a drum A speaker drives a circular rubber membrane under tension while illuminated with a strobe. 3D40.40 standing waves in a drum A circular rubber membrane with a pattern is illuminated with a strobe and driven from below by a 12" loudspeaker. Pictures. 3D40.40 drumhead A speaker drives a drumhead. 3D40.41 vibrations in a circular membrane The eigenfrequencies of (21) agree closely with the theoretical values. Air damping is removed by using a wire mesh driven magnetically. 3D40.45 bubble membrane modes Use a large right angle PVC fitting. 3D40.45 soap film membrane modes Light from a slide projector is reflected off a soap film with a black cloth and speaker behind. 3D40.45 bubble membrane modes A simple technique to drive bubble membranes of various shapes with a speaker. 3D40.50 musical goblets Rub the edge of a goblet with a wet finger. 3D40.50 glass tumbler Rub a finger dipped in vinegar around the top of a crystal goblet. 3D40.51 standing waves in a bowl A 15 l flask is cut in half to form a bowl which is bowed to produce standing waves. Suspended ping pong balls indicate nodes and loops. 3D40.51 bowing the bowl Suspend four pith balls so they touch the edge of a bowl and bow between two of the balls. 3D40.52 "whispering" waves in a wineglass A thorough discussion of surface waves in vessels, including ethylene glycol in a trifle dish. 3D40.52 wineglass acoustics A study of wineglass acoustics. 3D40.53 wine glass waves, etc. Seven questions about wine glass waves are answered. Pictures of a glass harmonica and a Chinese "water spouting basin". 3D40.55 shattering goblet Laboratory beakers are shattered in a chamber with a small piece of folded paper over the rim serving as a resonance detector. 3D40.55 shattering goblet Break a lead crystal goblet with amplified sound. 3D40.55 glass breaking with sound Large amplitude sound at the resonant frequency is directed at a beaker. 3D40.60 wind chimes Directions for making wind chimes. Some discussion of the perception of complex tones. 3D40.60 aeolian "bull roarer" The Australian "bull-roarer" produces a loud noise due to eddies in the air. 3D40.65 bull roarer 3D40.90 spherical oscillations movie A description by the author of a computer generated movie of spherical oscillations.

• 3D40.32 [:ChladniPlateViolin:Chladni Plate: Violin]

3D42. Percussion Instruments

3D46. Tuning Forks

3D46.15 tuning fork sets Various sets of tuning forks. 3D46.16 tuning fork Use a microphone and oscilloscope to display the waveforms of 256, 512, and 1024 Hz tuning forks. 3D46.20 tuning forks Strike two tuning forks. Hold one against the table and the other in the air. When the first is no longer audible, hold the second on the table. 3D46.21 tuning forks Compare losses of tuning forks of steel and alloy, on and off a resonator box. 3D46.22 adjustable tuning fork Adjust masses on each tine of a large fork and show the waveform on an oscilloscope. Mistuned forks damp quickly. 3D46.25 modulation of sound waves Two tuning forks of slightly different frequencies mounted on resonant boxes couple when the amplitude is varied by an oscillating barrier between them. 3D46.30 low frequency tuning fork Tuning fork motion can be studied with a large fork. 3D46.31 project a tuning fork Stroboscopically shadow project a vibrating tuning fork on a screen. 3D46.40 vowel tuning forks A set of tuning forks made to give sounds that sound like the vowels. 3D46.45 quadrupole nature of a tuning fork Hold a tuning fork close to the ear and rotate it. 3D46.90 frequency standard tuning forks Driven precision tuning forks of 400 and 100 Hz are used as secondary frequency standards. 3D46.90 Electronically driven tuning fork A tube circuit for driving a tuning fork. 3D46.90 electrically driven fork A vacuum tube circuit for driving tuning forks.

3D50. Electronic Instruments

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