Research for improving my prototype- Sound of Light.

After a few exciting experiments I am now set to design a couple of things in detail.

In an attempt to build a device that amplifies sounds/tones into light which hopefully doesn't need a lot of electrical equipment I am looking at everything from the roots.

What is Sound?

Sound is a form of energy, just like electricity and light. Sound is made when air molecules vibrate and move in a pattern called waves/sound waves.

(Having said this light travels in waves as well. But Light waves are a little more complicated as they do not need a medium to travel through. They can travel through a vacuum.)

But how do we hear sound! Of course through ears but what goes on inside these ears? To know this watch the following video:

Great so now I know how an ear works but what's it got to do with amplification of sound?With not much use of this information right now it could prove handy at a later stage.

Inorder to amplify sound I need to restructure my prototype "Sound of Light".

I will be looking at how microphones work, how a seismoscope works and so on.

Microphones and their design-

A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electric signal.

There are many different kinds of microphones but the one that I found were the best and are rare at the same time are ribbon microphones.

Considered by many as the most natural-sounding microphone ever made, Ribbon Mics are a type of dynamic microphone that use a thin aluminum, duraluminum or nanofilm ribbon placed between the poles of a magnet to generate voltages by electromagnet induction. Ribbon microphones are typically bidirectional, meaning they pick up sounds equally well from either side of the microphone.

The following is an image and diagram of a ribbion microphone -

Now this is very technical but what is useful here is the design in its technicality. I.E. how beautifully is one energy converted into another. As of now I am not sure how I'll use this.

Seismoscope -

Seismoscopes are instruments that measure motions of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources. Records of seismic waves allow seismologists to map the interior of the Earth, and locate and measure the size of these different sources.

Diagram of a Home made seismograph -

This is great for very sensitive vibrations produced by sound. I will be looking at different ways of incorporating this design into my device.

Drums -

Since I used the basic idea of a drum in my design I will now understand how a professional drum is made and understand the history of the same.

The drum is a member of the percussion group of musical instruments, technically classified as the membranous. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over a shell and struck, either directly with the player's hands, or with a drumstick, to produce sound. There is usually a "resonance head" on the underside of the drum. Other techniques have been used to cause drums to make sound, such as the thumb roll. Drums are the world's oldest and most ubiquitous musical instruments, and the basic design has remained virtually unchanged for thousands of years.

The shell almost invariably has a circular opening over which the drumhead is stretched, but the shape of the remainder of the shell varies widely. In the western musical tradition, the most usual shape is a cylinder, although timpani, for example, use bowl-shaped shells. Other shapes include a frame design (tar, Bodhran), truncated cones (bongo drums, Ashiko), goblet shaped(djembe), and joined truncated cones (talking drums).

Drums with cylindrical shells can be open at one end (as is the case with timbales), or can have two drum heads. Single-headed drums normally consist of a skin which is stretched over an enclosed space, or over one of the ends of a hollow vessel. Drums with two heads covering both ends of a cylindrical shell often have a small hole somewhat halfway between the two heads; the shell forms a resonating chamber for the resulting sound. Exceptions include the African slit drum, also known as a log drum as it is made from a hollowed-out tree trunk, and the Caribbean steel Drum, made from a metal barrel. Drums with two heads can also have a set of wires, called snares, held across the bottom head, top head, or both heads, hence the name snare drum.

On modern band and orchestral drums, the drumhead is placed over the opening of the drum, which in turn is held onto the shell by a "counterhoop" (or "rim), which is then held by means of a number of tuning screws called "tension rods" which screw into lugs placed evenly around the circumference. The head's tension can be adjusted by loosening or tightening the rods. Many such drums have six to ten tension rods. The sound of a drum depends on several variables, including shape, size and thickness of its shell, materials from which the shell was made, counterhoop material, type of drumhead used and tension applied to it, position of the drum, location, and the velocity and angle in which it is struck.

Prior to the invention of tension rods drum skins were attached and tuned by rope systems such as that used on the Djembe or pegs and ropes such as that used on Ewe Drums, a system rarely used today, although sometimes seen on regimental marching band snare drums.

Where I come from drums have a connection with hindu mythology. The following instrument is the pakhawaj. It is a very ancient drum and is mentioned in the oldest scripture available (Rigveda).The oldest percussion instrument in hindustani classical music and one of the oldest in the world. it is said that the tabla is derived from it when it broke into two pieces. its connection goes to hindu mythology where the teachings of lord shiva was played by lord ganesha through the pakhawaj. the "bol"s used are actually the divine language where each has its own meaning.

Pakhavaj is made from the one piece of the wood. The bass side is bigger than the treble side. Pakhavaj’s Bayan (left side) is not inked and dough is used to get the bass sound. Higher or lower notes are achieved by putting more or less dough on the head. Because Pakhavaj is one piece, so hitting one side makes both sides ring. That ring distinguishes Pakhavaj’s all over sound from Tabla. The ring is especially obvious when a Thaap (all four fingers flat like ‘Te’ sound in Tabla) is played. A lot of Thaap sounds are used in Pakhavaj, where in Tabla lots of individual fingers are used to get different sounds.
The high side of Pakhavaj is always tuned and the procedure to tune it exactly the same as Tabla’s Dayan.

Tabla-

How to make Native american Drums-

How to make modern day snare drums -

Acoustics in Architecture and uses -

Taj Mahal :

The Taj Mahal is a mausoleum located in Agra, India. It is one of the most recognizable structures in the world. It was built by Mughal Empror Shah Jahan in memory of his third wife, Mumtaz Mahal. It is widely considered as one of the most beautiful buildings in the world and stands as a symbol of eternal love.

Taj Mahal is the finest example of Mughal architecture, a style that combines elements from Persian, Islamic and Indian architectural styles.

The acoustics inside the main dome cause the single note of a flute to reverberate five times.

Echo Chamber -

While looking at acoustics in old palaces I came across the concept of Echo Chambers.

These days even the most basic processors offer a wide variety of reverb options at the touch of a button. Years ago, however, the vast majority of recording engineers were wont to create their own reverberation effects using reflective rooms known as live echo chambers. Deceptively small (anywhere from 10 to 15 feet long on average, with a low ceiling) despite their enormous sound, echo chambers aped the kind of naturally occurring ambience heard in large concert halls. For years studio technicians would remedy a case of the dries by recording singers in adjacent stairwells or even bathrooms. By having a chamber on the premises, though, engineers could count on a dedicated, controlled space solely for the purpose of adding echo.

Rather than placing the performer inside the chamber, the engineer would send the signal from the console to a loudspeaker situated in a corner of the room. A microphone positioned at the opposite end (in order to maximize the echo effect) returned the reverberated sound back to the console, where it was then mixed with the original untreated signal. Adjusting the amount of reverb was simply a matter of increasing or decreasing the send or return signal, or even moving the microphone closer to or farther away from the speaker.

Making the chamber :-

Start by squaring off the chamber with a long wall made of Sheetrock, fastening the Sheetrock on both sides of the wall frame to a stud every 16 inches. If possible, angle the wall slightly inward (or outward) to create a trapezoidal space, so the sound waves can bounce in different directions. Use the Sheetrock to make a ceiling as well. For an opening, all you'll need is a simple cutout about three feet square, using a hatch made of soundboard for a covering.

Now comes the important part: making an interior that's as solid, smooth, and reflective as possible. Some people use bathroom tile, which will work great but is ridiculously expensive. The majority of chambers are composed of plaster (a bargain at about five bucks per 50-pound bag) or, specifically, portland cement plaster, which is a standard plaster cut with some cement and lime. Once it's mixed, you have about 15 to 20 minutes to hang the plaster on the walls before it turns to rock. Therefore, mix the plaster in small batches and apply it in several layers to both the Sheetrock wall and the preexisting concrete wall, smoothing each layer with a large wet sponge once the plaster begins to set.

Another old trick involves adding hard rounded corners to your chamber to help keep the sound waves moving. Some of the best chambers were actually oval-shaped for this reason. Simply attach a length of Sheetrock or plywood to each corner of the room and then cover it with plaster in several layers.

To make the interior as reflective as possible, chamber builders typically covered their walls, ceiling, and floor with several coats of shellac or even oil-based marine paint (and given the lack of ventilation, nearly asphyxiated themselves in the process). To make sure you're around to enjoy the finished product, use a high-gloss latex paint instead. Be sure to cover the inside of the soundboard hatchway as well.

Though a good extension cable would suffice, it's not a bad idea to bring some dedicated power into the room. Wiring in a combination porcelain lamp holder/outlet box, or something similar, will provide you with light as well as juice — handy should you decide to use a condenser mic, for instance.

In order to keep those sound waves in motion, the chamber should almost resemble the inside of a refrigerator, says producer Mark Neill, owner of San Diego-based Soil of the South Studios.

Using all the above data I will now design my prototype in a better way. I have learnt and understood the concept of sound travelling in waves and will try to use it to the maximum.