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What is the meaning of FB mark on the cone the of the Pioneer CS-99A speaker?
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∙ 15y ago
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∙ 15y ago
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How does a speaker work?
Basically the movement of the speaker is the cause of the stereo (mono speakers) making the noise via induction. The Induction is the result of controlled oscillation of electrical current.A speaker is essentially an air pump. I like to say the bigger the pump the bigger the sound!!!A driver is a device that reproduces sound. Drivers consist of woofers, subwoofers, tweeters, midranges, compression horns etc. A driver consists of a magnet assembly, a metal or composite basket/frame, coil and cone or dome.A driver has a coil of wire that is electrically attached to your amplifier. The coil is the electro magnet not the magnet itself. The magnet is usually made of ceramic but used to be made of Alnico (Aluminum, Nickel, Cobalt; expensive compared to ceramic) and is more often now made of neodymium (a lighter stronger material than ceramic). The magnet has a permanent magnetic polarity that does not change. When the coil of wire is placed inside the magnet assembly "pole piece" and an alternating signal is placed thru the coil it will cause the coil to oscillate as the coil will now attract and repel within the magnet assembly as the polarity changes on the coil. The coil is attached to a cone (or dome in the case of tweeters and some midranges) which is capable of moving air more effectively.Speakers consist of these drivers usually a woofer, a tweeter, and sometimes a midrange. A speaker will almost always also have a crossover network which is basically a filter network that effectively divides the signals to each driver so that the bass only goes to the woofers and the high freq only goes to the tweeters.Typical speaker arrangements contain multiple speakers: two for a simple stereo system, or more for more recent systems. All multi-speaker systems need observing the polarity such that the coils in all speakers make the same, synchronized, movement: in a multi-speaker system, some sounds only come out of the left speaker, or the right speaker. That makes the stereo effect. The majority of the sound, however, is being emmitted through all speakers at the same time. The bass drum, for example, can typically be heard through the left and the right speaker at the same time.Wiring all the speakers in such a system while observing their polarity allows the speakers to make a syncronized movement. For example, when the bass drum hits, all affected speaker coils would make a movememt towards you, then away from you, etc. If one of the speakers is wired with the reverse polarity, this speaker would start by moving away from you, then towards you. Air would simply be shifted back and forth between the speakers, instead of applying pressure on your ear drums.To avoid that effect of lost sound energy, speakers should be wired up with the same polarity even though they are driven by an alternating current (AC) signal.AdditionalAnother type of speaker is the electrostatic loudspeaker. Electrostatic loudspeakers are generally very much more expensive than the electromagnetic loudspeaker described above and, in most cases, far superior. Physically, they look completely different from conventional loudspeakers, usually taller and wider, but very much thinner (rather like a plasma television compared to a CRT television!).Electrostatic loudspeakers work on the principle of attraction and repulsion between electric charges. The general principle is as follows. The diaphragm ('driver') , a large rectangular flexible sheet of material, such as mylar, is coated with a conducting layer and placed between two large metallic perforated sheets. A high DC voltage is placed between across this arrangement and the audio signal is impressed upon the voltage, causing the polarities to change in magnitude and direction in accordance with the musical signal. The result is that the flexible sheet will then move, acting in much the same way as the diaphragm described in the previous answer. Compared with electromagnetic loudspeakers, the diaphragm is much lighter and reacts far more rapidly to variations in signal. Furthermore, because the whole of the surface of the diaphragm is charged, the resulting forces are applied to the whole of the surface of the diaphragm rather than being 'pushed' or 'pulled' by a separate coil -as is the case with the magnetic loudspeaker.Like electromagnetic loudspeakers, electrostatic loudspeakers also have 'woofers' and 'tweeters' -different-sized rectangular diaphragms.Because electrostatic loudspeakers require a very high voltage (thousands of volts) to operate, they each have a heavy built-in transformer and rectification system and must, therefore, be connected to an electricity supply.Electrostatic loudspeakers were developed, commercially, by a British hi-fi company called Quad, which has been manufacturing them since the 1950s.
What is flux valve and its operation?
Fluxvalve Theory 10. The fluxvalve , consists of a sensitive pendulous element which is free to swing within limits (usually ± 25°) but fixed to the aircraft in azimuth. The element is suspended by a Hooke's Joint with the whole assembly being hermetically sealed in a case partially filled with oil to dampen oscillations. A deviation compensator is usually mounted on top of the unit. 73 Radio Magnetic Compass 11. The pendulous detector element resembles a three spoke wheel with the spokes 120° apart and slotted through the rim. The rim forms a collector horn for each spoke. The horns and spokes are made up of a series of metal laminations having a high magnetic permeability. Each spoke has a vertical cross-section similar to that shown in Fig 12-2. The spoke consists of two superimposed legs which are separated by plastic material and opened out to enclose the central hub cone. This cone has an exciter coil wound round it on a vertical axis, and each spoke has a pick-off coil wound round both legs on a horizontal axis. The exciter coil is fed with 400 Hz single phase AC. The output of the secondary or pick-off coil is an 800 Hz single phase AC current, the amplitude and phase representing the relationship of magnetic North to the aircraft longitudinal axis (magnetic heading). Fig 12-2: Vertical Cross-section of Spoke 12. In order to appreciate the operation of the fluxvalve it is necessary to consider an individual spoke. The function of a spoke will be developed in a series of diagrams (Figs 12-3 to 12-10). 13. If a single coil is placed in a magnetic field, the magnetic flux passing through the coil is maximum when the axis of the coil is in line with the direction of the field, zero when the coil lies at right angles to the field, and maximum but of opposite sense relative to the coil when turned 180° from its original position. For a coil placed at an angle θ to a field of strength H (Fig 12-3) the field can be resolved into two components, one along the coil equal to H cos θ and the other at right angles to the coil equal to H sin θ. The H cos θ component is parallel to the coil and is the effective flux producing element. Therefore, the total flux passing through the coil is proportional to the cosine of the angle between the direction of the coil axis and the direction of the field. The coil output curve is shown at Fig 12-4. If the coil is in the horizontal plane with its axis parallel with the aircraft longitudinal axis, its output is affected by the horizontal component of the Earth's magnetic field and the flux passing through the coil is proportional to the magnetic heading of the aircraft. Fig 12-3: Magnetic Flux Components Fig 12-4: Variation of Flux with Theta 14. Unfortunately, the simple concept just described cannot be used without modification as a heading reference system for two important reasons. Firstly, the voltage induced into a coil depends FIS Book 4: Instruments 74 on the rate of change of flux. Therefore, once established on a heading, there would be no change of flux and, consequently, no induced voltage. Secondly, the output of the simple detection device would be subject to heading ambiguity, i.e. there are always two headings which cause the same induced output voltage. Therefore, the problem that must be solved is how to produce an output waveform which is proportional in some way (frequency, phase or amplitude) to the components of the Earth's field and linked with the coil. This is achieved in the fluxvalve by introducing an alternating magnetic field in addition to the static field caused by the horizontal component of the Earth's magnetic field. 15. Fig 12-5 shows the relationship between flux density (B) and magnetizing force (H) known as the hysteresis loop for the permalloy commonly used in the legs of the flux valve spokes. Permalloy has a very high magnetic permeability (μ = B/H) and a corresponding low hysteresis loss. In the following discussion the hysteresis loop is represented by a single line curve. Fig 12-5: Hysteresis Curve for Permalloy Fig 12-6: Simple Fluxvalve Fig 12-7: The Effect of Excitation Current in the Top Leg Only 16. One spoke of the three-spoke fluxvalve is shown diagrammatically in Fig 12-6. It consists of a pair of soft iron (usually permalloy) cones each wound with a primary coil. The winding on one core is the reverse of that on the other. The AC supply is just sufficient, at peak power, to saturate magnetically each of the parallel soft iron cores. A secondary coil, wound round the two primaries, is linked with the circuit, and any change of flux through it induces a voltage and current flows. 17. Fig 12-7 shows the 400 Hz alternating flux induced in the top leg by the excitation current considering only the top leg of the spoke and the effect of the excitation. 75 Radio Magnetic Compass 18. Now considering the bottom leg only; the flux induced in this leg by the excitation current will at any instant be in the opposite direction to that induced in the top leg, i.e. the flux in the bottom leg is 180° out of phase with the flux in the top leg as shown in Fig 12-8. 19. Since the top and bottom legs are identical, the amplitudes of the flux of the two legs are equal but 180° out of phase with each other relative to the pick-off coil, which is wound round both legs. Therefore, the resultant flux cutting the pick-off coil, which is the algebraic sum of the flux in the top and bottom legs is zero as shown in Fig 12-9. Fig 12-9: The Effect of the Excitation Current in Both Legs Fig 12-8: The Effect of the Excitation Current in the Bottom Leg Only 20. If the horizontal component of the Earth's magnetic field (H) is now added in line with the spoke, it will induce a steady flux in both legs of the spoke which will be added to the flux due to the excitation current. The effect, as shown in Fig 12-10, will be to bias the datum for the magnetizing force, due to the excitation current, on the B-H curve by an amount equal to H. The strength of the excitation current is so arranged that the effect of the introduction of the Earth's magnetic field component is to bring the flux density curves in Fig 12-10 onto the saturation part of the hysteresis curve. The resultant flux cutting the pick-off coil, which is the algebraic sum of the fluxes in the top and bottom legs, will no longer be Fig 12-10: The Combine Effects of the Excitation Current and the Component of the Earth's Field zero but will have a resultant proportional in amplitude to heading. The emf induced in the pick-off coil FIS Book 4: Instruments 76 is proportional to the rate of change of flux cutting the coil and therefore will have a waveform approximating to a sine wave at 800 Hz, i.e. twice the frequency of the excitation current as shown in Fig 12-10. It has been found by experiment that the amplitude of the emf is proportional to H. Therefore, the emf in the pick-off coil is a measure of H, i.e. the horizontal component of the Earth's magnetic field in line with the spoke. This should be apparent from Fig 12-10 in that, if a greater H is detected, the excitation current is biased further from the mid-point of the hysteresis curve, and the imbalance between the upper and lower leg fluxes will increase. Therefore, a greater resultant flux exists which will induce an emf of greater amplitude in the pick-off coil. A plot of the amplitude of the pick-off coil output voltage would show that it varies as the cosine of the magnetic heading. 21. Limitations of the Simple Single Spoke Detector. It should be apparent that there are two magnetic headings corresponding to zero flux (90° and 270°) and two headings corresponding to a maximum flux. The two maximum values give the same reading on an AC voltmeter since the instrument cannot take into account the direction of the voltage. For any other value of flux (other than zero), there will be four headings corresponding to a single voltmeter reading. This ambiguity is overcome by using a fluxvalve having three spokes (each spoke similar to the single spoked device previously discussed) with 120° separation as shown in Fig 12-11. Regardless of the heading, at least two of the spokes will have a voltage induced and their vector sum points to magnetic North (Fig 12-12). The simple one-spoke detector suffers from another limitation in that the value of H changes with magnetic latitude. This produces a change in the static flux linking the spoke, even though the heading may remain unchanged. This limitation is Fig 12-11: Detector Unit and Transmission System - schematic Fig 12-12: Operation of the Three-spoke Fluxvalve Fig 12-13: Eliminating Latitude Ambiguity 77 Radio Magnetic Compass overcome in the three-spoke fluxvalve because the flux associated with each spoke will change in proportion to the change in H. The resultant field across the receiver stator is still aligned with H (Fig 12-13). 22. In the three-spoke fluxvalve a single primary coil excites all six cores. If a single arm of the fluxvalve is considered, it will be apparent that the top and the bottom of the exciter coil have opposite polarity. The flux induced in the upper core of the spoke is equal and opposite to that induced in the lower core and this is exactly the effect produced by the primary windings in the simple fluxvalve. The three arms of the fluxvalve are wound with secondary or pick-off coils which are star connected. The exciter coil is fed with 400 Hz single-phase current so that each of the three pick-off coils has an emf at 800 Hz induced in it whose amplitude is proportional to the magnetic heading of the aircraft. Each core of the fluxvalve is fitted with a flux collector horn to concentrate the Earth's lines of force through the core. This increases the static flux and therefore the induced voltage.
What is the meaning of FB mark on the cone the of the Pioneer CS 99A speaker?
Free-beating
How can you tell how big a speaker is?
To approximate the diameter of a speaker cone, find the approximate center. And then stick a ruler across the center of the speaker cone. This will give you the size of the speaker.
How to remove magnet from a speaker?
To remove a magnet in a speaker, first detach the grill in the front of the speaker, second unscrew the speaker after that remove the speaker from the cabinet and cut the speaker cone. Lastly, gently discard the magnet from the speaker cone.
What is the difference between a two way and three way speaker?
A two-way speaker has two speaker cones built into one speaker assembly: one cone to generate lower-frequency sounds and one cone to generate higher-frequency sounds. The low-range speaker cone is larger, the high-range cone is smaller. In car speakers, the low-range speaker cone usually occupies most of the area of the speaker, and is made from a light-weight, paper-like material, sometimes painted black, sometimes gray. A three way speaker has three speaker cones built into the assembly, an additional cone for mid-range frequency sounds.
Who invented speaker cone?
Clair Farrand
What is the technical name for the cone of the speaker?
Diaphragm
What do you mean by 2 way audio system?
it means that the speaker has a speaker cone for the bass and mid frequencies and a tweeter for the high frequencies. this makes it a 2 way audio system. a three way audio system would have a speaker cone for the bass, another speaker cone for the mids, and a tweeter for the highs.
You home theater speakers are crackling What should you do?
The most common cause is bad wiring. Check the connections or replace the speaker wiring. If that does not work, check which speaker has the problem and see if a cone is blown. To do this, place your ear near the cone and gently press it in (don't push to hard). If the cone is blown you will hear a raspy rubbing sound when the cone moves. Replace the cone or the speaker if it is blown. If this does not work, change your speaker connections around to see if it is the amplifier.
What is causing the speaker 0n your screen to distort the voices?
Torn speaker cone is one possibility.
Where is a magnet located on a speaker?
At the back of the cone where the wires connect in
Inside a stereo speaker you will find two permanent magnets one on the cone and one near the cone?
False
What is the vibrating part of loud speaker?
The cone of a speaker is what vibrates to make sound. In some hard speakers with a rigid cone-shaped horn, a flexible diaphragm vibrates. Withut the vibration, you get no sound.
