Home Made Speakers

What are Speakers?

Speakers are one of the most common output devices used with computer systems. Some speakers are designed to work specifically with computers, while others can be hooked up to any type of sound system. Regardless of their design, the purpose of speakers is to produce audio output that can be heard by the listener.


History

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When recorded audio first found its way into American homes via Thomas Edison's phonograph, the playback devices were mechanically powered. Large, tapered horns were used to project sound (See the photo on the right). In 1898 Oliver Lodge invented a "bellowing telephone" loudspeaker which was very similar to the modern, common cone speaker. However, because electrical signal amplification was not possible until the invention of the triode vacuum tube in 1906, Lodge's "bellowing telephone" wasn't used as a loudspeaker for any audio system. Later, in the 1920s, Bell Laboratories began to develope an audio system to playback the newly invented, electrically cut phonograph records.Bell Laboratories developed many speaker prototypes including designs based on Lodge's cone, as well as electrostatic type loudspeakers. Due to the large size of the electrostatic design, Bell Laboratories ultimately went with a cone design. The moving-coil (dynamic) cone speakers developed by Bell Laboratories laid the foundation for the common cone speakers we use today.


Types of Speakers

1.Architectural Speakers

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Staying visually discrete without enormous sonic compromise, in-wall and in-ceiling speakers provide sound to discretely styled home theater systems and multiroom distributed audio. These speakers mount directly to the wall or ceiling, featuring grilles and bezels that are painted or stained to match the mounting surface. Many of these speakers offer swiveling woofers and tweeters, allowing you to aim the sound toward the most advantageous locations. Although the wiring is more complex, involving routing through walls and ceilings, the near-invisible nature of these products mitigates for many the difficulty with installation and slight reduction in sonic fidelity.


2.Mobile Audio

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Mobile audio speakers are very similar to home speakers, with the primary difference being that they do not have enclosures. Car and marine speakers come in combination woofer/tweeter versions known as coaxial speakers. This speaker type is most often used to upgrade from factory speakers, and normally are the less expensive option among mobile speakers. Upgrading from these designs are component speakers, featuring a separate woofer and tweeter for increased mounting options. Component speakers are normally among or approaching the upper echelon of car audio products, offering superior power handling and sound quality. Subwoofers add the low end that smaller speakers cannot, rounding out the sound and providing an engaging visceral quality to the sonic experience. Coaxial and component speakers mount in doors and decks, while subwoofers conventionally install in an enclosure of the proper size and volume.


3.Book Shelf and Floorstanding Options

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Comprising the majority of home audio speakers, bookshelf and floorstanding models use a variety of enclosure shapes and sizes to achieve the manufacturer's target sonic goals. Bookshelf speakers come in a variety of sizes, designed to mount on shelves, in an entertainment center or on stands. Floorstanding speakers are found in three- and four-way designs, referring to the number of crossover points in the speaker. For example, a floorstanding design with a woofer, tweeter and midrange is normally considered a three-way speaker. Bookshelf speakers are two-way designs, featuring only a woofer and tweeter. The choice of speaker depends on space in the room and whether you intend to use a subwoofer to provide muscle and body to bass drums and guitar. Home-theater arrays use a pair of main speakers, center channel for dialogue, subwoofer and at least one pair of surround speakers. In this case, the subwoofer provides the ".1" channel in a 5.1 or 7.1 system, re-creating explosions and gunshots with exciting impact.


4.Sub/Sat System

Subwoofer/satellite systems feature five or more small speakers, using a subwoofer to handle nearly all of the bass duties. These speaker types are commonly used when low speaker visibility is desired, low amplifier power is used or if in-wall or in-ceiling speaker installation is impractical. These speaker systems are often seen as "home theater in a box" packages, offering the speakers, receiver and sometimes a source like a DVD or Blu-ray player. Very often, these systems are not upgradable, as the receiver is designed for use only with the speakers included with the unit.

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5.Desktop Audio

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Speakers for a quick connection to an iPod or other MP3 player are great for bedside music or in a small room or office space. These units feature an integrated dock, built-in speakers and sometimes a built-in AM/FM tuner. Many of these designs are compatible with Apple's AirPlay protocol, enabling wireless streaming from an iPhone or iPod Touch to the speakers without having to physically dock the device. Other computer speakers come in surround and stereo formats, using the headphone output or a USB connection. These speakers also usually have some provision for headphone or portable audio-device connectivity, simplifying connections and reducing desktop wiring clutter.


Components of a Speaker

Typical speaker cones range from 1.5 to 18 inches in diameter. Speakers of this size can consume from 0.25-250 Watts (W), resonate at a frequency of 16-4kHz, and have a sensitivity level of up to 95 Decibels (dB)

Magnet Structure — Two pieces of oppositely oriented magnets that produce a radial field from the inner to outer magnet
Voice Coil — Carries the current so that it is always moving in a plane perpendicular to the magnetic field; thus the force always acts on the same axis
Spider — Vibrates rigidly with the voice coil and translates the mechanical energy to the cone
Cone — Produces pressure waves from its surface due to the oscillation of the spider
Basket — Holds the components together firmly, preventing motion in parts like the magnet structure
Dust Cap — Protects the cone and circuitry from dust … a clean speaker is a happy speaker :)

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Working

1. The electric signal passes through the wire in the form of an analog, sinusoidal (or other) wave.
2. The signal enters the voice coil, wrapping around the inner magnet (in the form of a solenoid).
3. A force is exerted from the stable magnet structure to the free-moving voice coil.
4. As the signal's amplitude and frequency change, the force on the voice coil undulates back and forth.
5. The voice coil rapidly vibrates along the axis of the magnet structure, thereby vibrating the cone.
6. As the voice cone vibrates, the air immediately around it is pressurized and rarified.
7. The pressurized air molecules propagate as a wave — this is sound.

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Reference

https://www.google.co.in/search?q=types+of+speakers&espv=2&biw=1366&bih=624&source=lnms&tbm=isch&sa=X&ei=rI1nVLjMFcq9ugSBpYCgDg&ved=0CAYQ_AUoAQ


Made by:

1. Madhav Varma(2014061)
2. Siddhant Verma(2014102)
3. Siddharth Arya(2014103)


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