1. Speakers Read Yamaha manual pgs 209-221. Read Yamaha manual pgs 209-221. The cone, usually made of paper, plastic or metal, is attached on the wide end to the suspension. The cone, usually made of paper, plastic or metal, is attached on the wide end to the suspension. The suspension, or surround, is a rim of flexible material that allows the cone to move, and is attached to the driver's metal frame, called the basket. The suspension, or surround, is a rim of flexible material that allows the cone to move, and is attached to the driver's metal frame, called the basket. The narrow end of the cone is connected to the voice coil. The narrow end of the cone is connected to the voice coil. The coil is attached to the basket by the spider, a ring of flexible material. The spider holds the coil in position, but allows it to move freely back and forth. The coil is attached to the basket by the spider, a ring of flexible material. The spider holds the coil in position, but allows it to move freely back and forth.

5. Speakers cont The voice coil is a coil of wire, usually wrapped around a piece of magnetic metal, such as iron. The voice coil is a coil of wire, usually wrapped around a piece of magnetic metal, such as iron.iron Running electrical current through the wire creates a magnetic field around the coil, magnetizing the metal it is wrapped around. Running electrical current through the wire creates a magnetic field around the coil, magnetizing the metal it is wrapped around. The field acts just like the magnetic field around a permanent magnet: It has a polar orientation -- a "north" end and and a "south" end -- and it is attracted to iron objects. The field acts just like the magnetic field around a permanent magnet: It has a polar orientation -- a "north" end and and a "south" end -- and it is attracted to iron objects. With an electromagnet you can alter the orientation of the poles. If you reverse the flow of the current, the north and south ends of the electromagnet switch. With an electromagnet you can alter the orientation of the poles. If you reverse the flow of the current, the north and south ends of the electromagnet switch.

6. Speakers cont Essentially, the amplifier is constantly switching the electrical signal, fluctuating between a positive charge and a negative charge Essentially, the amplifier is constantly switching the electrical signal, fluctuating between a positive charge and a negative chargeamplifier The current going through the speaker moves one way and then reverses and flows the other way causing the voice coil to move in and out. The current going through the speaker moves one way and then reverses and flows the other way causing the voice coil to move in and out.

7. Check this out Howstuffworks "How Speakers Work" Howstuffworks "How Speakers Work" Howstuffworks "How Speakers Work" Howstuffworks "How Speakers Work"

8. Speakers cont When the coil moves, it pushes and pulls on the speaker cone. This vibrates the air in front of the speaker, creating sound waves. When the coil moves, it pushes and pulls on the speaker cone. This vibrates the air in front of the speaker, creating sound waves. The electrical audio signal from the amplifier dictates the rate and distance that the voice coil moves. The electrical audio signal from the amplifier dictates the rate and distance that the voice coil moves. This, in turn, determines the frequency and amplitude of the sound waves produced by the diaphragm. That is how a speaker works. This, in turn, determines the frequency and amplitude of the sound waves produced by the diaphragm. That is how a speaker works.

9. Speaker Impedance Speaker impedance is the load or resistance that the amplifier sees when it is driving the speaker. Speaker impedance is the load or resistance that the amplifier sees when it is driving the speaker. Speakers come built in various impedances. Usually 16, 8 or 4 ohms. Speakers come built in various impedances. Usually 16, 8 or 4 ohms. Generally the lower the impedance the more efficient the speaker is. Generally the lower the impedance the more efficient the speaker is. A speakers efficiency is measured in db/watt @ 1 meter. A speakers efficiency is measured in db/watt @ 1 meter. Every time you hook up another speaker in parallel the impedance gets dropped by ½ Every time you hook up another speaker in parallel the impedance gets dropped by ½ The lower the impedance the harder the amp has to work to drive the load of the speakers. The lower the impedance the harder the amp has to work to drive the load of the speakers.

10. Speaker Impedance Some amplifiers are rated to safely run at a 2 ohm load. Generally try to avoid this as it makes the amplifiers work very hard to drive the speakers. Harder work = more heat = greater chance of failure. Try to keep your speakers set up to not make the amp drive a greater load than 4 ohms. Some amplifiers are rated to safely run at a 2 ohm load. Generally try to avoid this as it makes the amplifiers work very hard to drive the speakers. Harder work = more heat = greater chance of failure. Try to keep your speakers set up to not make the amp drive a greater load than 4 ohms.

11. Speaker Power Ratings Continuous: eg. 120 watts Refers to the level of long term average power that the loudspeaker will handle. Continuous: eg. 120 watts Refers to the level of long term average power that the loudspeaker will handle. It is usually measured using a sine wave or weighted noise input It is usually measured using a sine wave or weighted noise input Program Power Handling: eg. 240 watts Program Power Handling: eg. 240 watts Is measured using a test signal that approximates a real world program signal. Actual program signals have less long term heating effect for a given power level. Is measured using a test signal that approximates a real world program signal. Actual program signals have less long term heating effect for a given power level.

12. Speaker Power Ratings Peak Power Handling: eg. 480 watts Peak Power Handling: eg. 480 watts Refers to the maximum instantaneous, short term power that loud speaker will handle, short term refers to intervals under a second, generally no more than 1/10th of a second. Refers to the maximum instantaneous, short term power that loud speaker will handle, short term refers to intervals under a second, generally no more than 1/10th of a second. Manufacturers tend to rate their speakers for more power handling than they can actually handle Manufacturers tend to rate their speakers for more power handling than they can actually handle You should underestimate the amount of PROGRAM power that a speaker is rated at and use that as the actual power that the speaker will handle in “real life” environments. You should underestimate the amount of PROGRAM power that a speaker is rated at and use that as the actual power that the speaker will handle in “real life” environments.

13. Compression Drivers and Horns A compression driver is used to reproduce High Frequency sound. A compression driver is used to reproduce High Frequency sound. They come in different sizes measured by their throat diameter. 1”, 1.5”, and 2” are the most common sizes. They come in different sizes measured by their throat diameter. 1”, 1.5”, and 2” are the most common sizes. These tiny speakers are attached to a horn to direct their energy at the audience in a controlled beam or pattern. These tiny speakers are attached to a horn to direct their energy at the audience in a controlled beam or pattern. Dispersion of a horn is the angle that it covers measured in degrees. Typical dispersion patterns for horns are 70-120 degrees horizontally and 60 or 40 degrees vertically. The wider the dispersion pattern the shorter the throw or distance the driver can send high frequency waveforms. Dispersion of a horn is the angle that it covers measured in degrees. Typical dispersion patterns for horns are 70-120 degrees horizontally and 60 or 40 degrees vertically. The wider the dispersion pattern the shorter the throw or distance the driver can send high frequency waveforms.

17. Speaker Enclosure Types SEALED ENCLOSURES SEALED ENCLOSURES In a sealed speaker setup, the driver diaphragm compresses air in the enclosure when it moves in and rarefies air when it moves out. In a sealed speaker setup, the driver diaphragm compresses air in the enclosure when it moves in and rarefies air when it moves out. These enclosures are less efficient than other designs because the amplifier has to boost the electrical signal to overcome the force of air pressure. The force serves a valuable function, however -- it acts like a spring to keep the driver in the right position. This makes for tighter, more precise sound reproduction. These enclosures are less efficient than other designs because the amplifier has to boost the electrical signal to overcome the force of air pressure. The force serves a valuable function, however -- it acts like a spring to keep the driver in the right position. This makes for tighter, more precise sound reproduction.

19. Speaker Enclosure Types BASS_REFLEX BASS_REFLEX Other enclosure designs redirect the inward pressure outward, using it to supplement the forward sound wave. The most common way to do this is to build a small port into the speaker. In these bass reflex speakers, the backward motion of the diaphragm pushes sound waves out of the port, boosting the overall sound level. The main advantage of bass reflex enclosures is efficiency. The power moving the driver is used to emit two sound waves rather than one. The disadvantage is that there is no air pressure difference to spring the driver back into place, so the sound production is not as precise. Other enclosure designs redirect the inward pressure outward, using it to supplement the forward sound wave. The most common way to do this is to build a small port into the speaker. In these bass reflex speakers, the backward motion of the diaphragm pushes sound waves out of the port, boosting the overall sound level. The main advantage of bass reflex enclosures is efficiency. The power moving the driver is used to emit two sound waves rather than one. The disadvantage is that there is no air pressure difference to spring the driver back into place, so the sound production is not as precise. More efficient, boomier sound, not as precise sound quality compared to sealed enclosure More efficient, boomier sound, not as precise sound quality compared to sealed enclosure

21. Speaker Enclosure Types A passive radiator speaker uses a second "passive" driver, or drone, to produce similar low frequency extension or efficiency increase or enclosure size reduction as do ported enclosures. In theory, such enclosures are variations of the bass reflex type, but with the advantage of avoiding a relatively small port or tube through which air moves, sometimes noisily. As well, tuning adjustments for a passive radiator are usually much easier. And with the disadvantage that a passive radiator requires precision construction quite like driver design, thus increasing costs A passive radiator speaker uses a second "passive" driver, or drone, to produce similar low frequency extension or efficiency increase or enclosure size reduction as do ported enclosures. In theory, such enclosures are variations of the bass reflex type, but with the advantage of avoiding a relatively small port or tube through which air moves, sometimes noisily. As well, tuning adjustments for a passive radiator are usually much easier. And with the disadvantage that a passive radiator requires precision construction quite like driver design, thus increasing costspassive radiatorpassive radiator

24. Line Arrays A line array is a group of radiating elements arrayed in a straight line, closely spaced and operating with equal amplitude and in phase A line array is a group of radiating elements arrayed in a straight line, closely spaced and operating with equal amplitude and in phase line arrays are useful in applications where sound must be projected over long distances. This is because line arrays afford very directional vertical coverage and thus project sound very effectively. line arrays are useful in applications where sound must be projected over long distances. This is because line arrays afford very directional vertical coverage and thus project sound very effectively.