Loudspeaker

This improves the bass response of the system. Moreover, the "hybrid" moniker gives the SUVs it's applied to an environmentally friendly image to counter the gas-guzzling reputation of SUVs in general. These incorporate a small hole, (called a port), in the speaker cabinet to allow the low frequencies generated by the rear of the woofer cone to escape from the cabinet in phase with that radiated from the front of the cone. While some manufacturers (most notably Toyota in the Lexus RX400h) are using added power generated from the hybrid systems primarily to give vehicles added performance, these hybrid SUVs still offer equal or better fuel efficiency than their conventionally-powered counterparts. Many multi driver systems use a bass reflex, or ported, design. A hybrid version of the Toyota Highlander is available, and a hybrid Mazda Tribute is in the pipeline. 'Multi driver' refers to any speaker system that contains two or more separate drive units, including woofers, midranges, tweeters, and sometimes horns or supertweeters. Shortly after the Escape Hybrid's introduction, Mercury introduced a hybrid version of its Mariner, which is a lightly restyled Ford Escape.

Home cinema systems generally include multi-driver systems. The 2005 Ford Escape Hybrid is the first hybrid SUV, with a hybrid version of the Lexus RX 400h also available. Despite its name, however, the unit is really a wireless receiver, amplifier and loudspeaker in a single box. For example the Hummer H1 is derived from the HMMWV developed for the US Armed Forces. So-called wireless loudspeakers are becoming popular in many applications, such as home theater, due to their convenience, removing the need to run speaker wire. SUVs targeted for use in civilization have traditionally originated from their more rugged all terrain counterparts. See also: Home theater in a box. Typical examples are the Land Rover, the Toyota Land Cruiser and the Lada Niva.

It is important to note that the sound channels offered to the speakers may be original individual channels (normal 5.1) or they may decode additional channels from the surround channels (This distribution can be accomplished by a Dolby Digital EX decoder, a THX Surround EX decoder) or they may be simulated (where the two surround channels are spread to center rear or twin rear speakers. Availablity of spare parts and the need to carry out repairs on the move dictate that established generic model vehicles with the bare minimum of electric and hydraulic systems predominate. They include :. It should be noted that use of SUVs is much rarer outside the USA, with people in these tending to use all terrain utility vehicles without the suburban refinements common to SUVs. There are various different speaker set-ups for home cinema speaker systems. Areas such as the Australian Outback, Africa, the Middle East and most of Asia can have limited blacktop roads and require the vehicle to have increased range, storage capacity, and all terrain handling. See also sound reproduction, electronics. There are a number of places where an SUV can be of benefit to its occupants.

See AudioSpotlights.com for more information. However they are still referred to in the UK as "roll-overs" due to their propensity to roll over. There are currently two devices available on the market that use ultrasound to create an audible "beam" of sound: the Audio Spotlight and Hypersonic Sound. Manufacturers have added car-level bumpers to reduce "submarining" in collisions- SUVs have therefore become somewhat safer for other road users in recent years. Pompei. [5]. The technology, termed the Audio Spotlight, was first made commercially available in 2000 by Holosonics, a company founded by Dr. In April 2005, William Cottrell, a 24-year-old American postgraduate student at Caltech was sentenced to more than eight years in federal prison and $3.5 million in fines for firebombing or vandalizing 125 SUVs at dealerships and a few homes in 2003.[4] Two of his associates fled the country to avoid prosecution.

Joseph Pompei of the Massachusetts Institute of Technology in 1998 (105th AES Conv, Preprint 4853, 1998) fully described a working device that reduced audible distortion essentially to that of a traditional loudspeaker. Other points of criticism: the gadgets may become troublesome (adding to repair bills), they add to the overall weight of the vehicle, the luxury features are simply toys for the rich and provide additional opportunities for the owner to flaunt himself/herself, and – in some instances – serve as distractions to drivers and causing an accident risk. F. Many critics see these features as simply unnecessary for normal commuting. These problems went unsolved until a paper published by Dr. In addition, some have criticized SUVs – particularly luxury-minded top-line models – because they come with electronic gadgets such as automotive navigation systems; power seats with memory settings; in-seat heaters and massage-type seat lumbar control; in-vehicle DVD players with flatscreen monitors; and vehicle stability control. This technology was originally developed by the US (and Russian) Navy for underwater sonar in the mid-1960s, and was briefly investigated by Japanese researchers in the early 1980s, but these efforts were abandoned due to extremely poor sound quality (high distortion) and substantial system cost. Some have gone as far as to connect recent oil crisis woes with widespread use of these vehicles.

Anyone or anything that disrupts the path of the beam will disturb the dispersion of the signal, and there are limitations, both to the frequency response and to the dispersion pattern of such devices. Others criticize SUVs for environmental reasons, pointing out that low fuel efficiency and high emissions make SUVs far less environmentally friendly than smaller cars. There are some criticisms of this approach. Some criticism of SUVs is based purely on their image as expensive, upscale status symbols for the (relatively) wealthy; and their stereotypically yuppie owners/drivers as arrogant, rude, and wasteful show-offs. This effect cannot be achieved with conventional loudspeakers, because sound at audible frequencies cannot be focused into such a narrow beam. For example, in braking, the high center of mass would direct an excessive weight shift to the front tyres, leading to an inefficiency of traction during braking. A listener outside the beam hears nothing. Due to the SUV's usually high weight and high center of mass, SUVs generally perform poorly in emergency manoeuvres.

The practical effect of this technology is that a beam of sound can be projected over a long distance to be heard only in a small, well-defined area. For instance, a 1999 Jeep Cherokee has a curb (empty) weight of 3300 lb (1500  kg), while a smaller car like the Volkswagen Golf diesel has a curb weight of 3100 lb (1400 kg). The air within the beam behaves in a nonlinear way and demodulates the ultrasound, resulting in sound that is audible only along the path of the beam, or that appears to radiate from any surface that the beam strikes. However sometimes, SUVs may look heavier than they actually are. The ultrasound is modulated-- it consists of an audible signal mixed with an ultrasonic frequency. These weights are all for vehicles fully loaded to GVWR, and most owners rarely reach full capacity. A transducer can be made to project a narrow beam of ultrasound that is powerful enough, (100 to 110 dBSPL) to change the speed of sound in the air that it passes through. For comparison, a midsize sedan such as the Honda Accord weighs 4080 lb (1851 kg) fully loaded.

Some speakers are electrostatically driven rather than via the usual electromechanical voice coil, thereby giving a more linear response; the disadvantage, however, is that the signal must be converted to a very high voltage and low current, which can be problematic for reliability and maintenance as they attract dust, and develop a tendency to arc, particularly where the dust provides a partial path; the point where the arc occurs often becomes more prone to arcing, as carbon builds up from the burned dust. Other vehicles can weigh as much as an SUV: the Dodge Grand Caravan exceeds the 6000 lb mark by 650 lb (295 kg), and the Honda Odyssey, at 5952 lb (2700 kg), and Kia Sedona, at 5959 lb (2703 kg), are close. A newer implementation of the Flat Panel involves the panel and an "exciter", such as the NXT technology. These laws are rarely enforced for SUVs, however, since these vehicles are seen as passenger vehicles instead of commercial trucks. Flat panel loudspeaker designs also work well as electrostatic loudspeakers. Rural bridges often have a 6000 lb (2700 kg) weight limit, and some large SUVs surpass this limit when loaded. An advantage of flat panel speakers is that the sound is perceived as being of uniform intensity over a wide range of distances from the speaker. The high gross vehicle weight rating of some larger SUVs (including the Ford Excursion or Hummer H2) technically limits their use on certain roads.

Some progress has been made using such rigid yet damped material as styrofoam, and there have been several flat panel systems demonstrated in recent years. Most gasoline luxury cars, limousines, SUV's, sport editions and tuned cars vary from 1L / 6KM to 1L / 12KM (±15-30 mpg). There are two, related problems with flat panel technology; firstly, that the flat panel is more flexible than the cone shape and therefore fails to move as a solid unit, and secondly that resonances in the panels are difficult to control, leading to considerable distortion in the reproduced sound. Average gasoline cars average from 1L / 8KM up to 1L /15KM (±20-35 mpg). These can then be either made in a neutral colour and hung on walls where they will be less noticeable, or can be deliberately painted with patterns in which case they can function decoratively. The smallest consumer gasoline cars average from 1 liter per 16KM up to 1 liter per 20KM (±40-50 mpg). One such attempt is the development of flat panels to act as sound sources. Luxury cars and limousines often have larger engines than SUV's.

There have also been many attempts to reduce the size of loudspeakers, or alternatively to make them less obvious. Sport editions of cars and tuned cars can have really bad fuel economics. In electronic digital to analog conversion, this is addressed by the use of Low-pass filters to eliminate the spurious upper frequencies produced; however, this approach cannot be used to solve the problem with this digital loudspeaker, since it is the last link in the audio chain. Standard cars with a diesel engine can weigh more than a regular SUV. Even accounting for the vastly lower efficiency of speaker drivers at such high frequencies, the result was to generate an unacceptably high level of ultrasonics accompanying the desired output. Luxury cars and mini vans can have the same or even more weight than a SUV. Secondly, since this system is converting digital signal to analog, the effect of aliasing is unavoidable, so that the audio output is "reflected" at equal amplitude in the frequency domain, on the other side of the sampling frequency. Although SUV's have the image of being fuel hogs, compared to sport editions of standard cars, luxury cars and mini vans the SUV's don't come out so bad.

For example, a 16 bit system to be compatible with the 16 bit audio CD standard, starting with a reasonable 2 square inch driver for the least significant bit, would require a total area for the drivers of over 900 square feet. Also, bear in mind that diesel is a more polluting fuel than gasoline, so a direct comparison of gallons/liters per mile/kilometer can be misleading. There are two problems with this design which led to its being abandoned as hopelessly impractical, however; firstly, a quick calculation shows that for a reasonable number of bits required for reasonable sound reproduction quality, the size of the system becomes very large. Note though that gasoline contains about 15% less energy than diesel fuel per unit of volume, so direct comparison of fuel economy numbers can be misleading. The next least significant bit drives a speaker of twice this area, and so on. Diesel-engined versions tend to show better fuel economy figures than gasoline-burning versions - checking a few offical figures shows that a small diesel 4x4 has better touring economy than the supercharged Mini Cooper S or many large saloon cars. The next least significant bit drives a speaker of twice the area (most often, but not necessarily, a ring around the previous driver), again to either full amplitude, or off. The low fuel economy is caused by.

(This allows for high efficiency in the amplifier, which at any time is either passing zero current, or required to drop the voltage by zero volts, therefore theoretically dissipating zero watts at all times). The more car-like SUVs tend to have a somewhat lower profile and better road performance tires, but often still have large, fuel-inefficient engines. The design of these is disarmingly simple; the least significant bit drives a tiny speaker driver, of whatever physical design seems appropriate; a value of "1" causes this driver to be driven full amplitude, a value of "0" causes it to be completely shut off. SUVs also often come with tires designed for off-road traction rather than low rolling resistance. Actual digital speaker driver technology not only exists, but is quite mature, having been experimented with extensively by Bell Labs as far back as the 1920s. The heavy suspension and large engines increases vehicle weight. Unfortunately, the recent marketing of plasma displays as high-end television sets and computer monitors has caused the "me-too" labeling of many speakers as "plasma" which have nothing whatsoever to do with plasma [8], much as the advent of digital audio caused the marketing of a large number of "digital" headphones and speakers, when all drive-units are analog in nature. The high profile of SUVs increases wind resistance.

A lower-priced variation on this theme is the use of a flame for the driver [7], flames being commonly electrically charged. As there is little incentive to change the design, SUVs have numerous fuel-inefficient features. As might be guessed, problems of maintenance and reliability for this design tend to make it very unsuitable for the mass market; the plasma is generated from a tank of helium which must be periodically refilled, for instance. The CAFE requirement for light trucks is an average of 20.7 mpg (US), versus 27.5 mpg (US) for passenger cars (11.4 and 8.6 L/100 km, respectively). Since plasma has minimal mass, but is charged and therefore can be manipulated by an electric field, the result is a very linear output at frequencies far higher than the audible range. government as light trucks, and thus are subject to the less strict light truck standard under the Corporate Average Fuel Economy (CAFE) regulations. The most exotic speaker design is undoubtedly the plasma arc loudspeaker, using electrical plasma as a driver [5], once commercially sold as the Ionovac [6]. The main reason is that SUVs are classified by the U.S.

Piezos have several advantages over conventional loudspeakers when applied to such purposes:. SUVs are as a class much less fuel efficient than comparable passenger vehicles. Computer speakers and portable radios are common examples. population consumes more gasoline than in previous years. Piezoelectric transducers, frequently used as beepers in watches etc., are often used as tweeters in cheap speaker systems. The recent popularity of SUVs is one reason the U.S. These include piezoelectric, electrostatic, and plasma arc loudspeakers. In Europe, from 2006 the fitting of bull bars, also known as grill guards or in Australia, roo bars, to vehicles such as 4x4s and SUVs will be illegal.

Other technologies can be used to convert the electrical signal into an audio signal. This is one of the chief motivations for the development of side-curtain airbags in standard autos. See more details here. The most notable statistic in SUV design crash incompatibility is an increase in fatalities when an SUV strikes the head of a passenger or driver in a side-impact collision. However, in practice it was found necessary to use a very complex cone made up of various materials at different points along its length, in order to maintain the waveform traveling evenly. These mass and design dangers are known as crash incompatibility issues in the crash testing industry, and are a topic of active research. This created a very effective omnidirectional radiator (although it suffered the same "planarity" effect as ribbon tweeters for higher-frequency sounds) and eliminated all problems of multiple drivers, such as crossover design, phase anomalies between drivers, etc. The higher ride and other design characteristics of many SUVs may also lead to greater damage to smaller crash partner cars.

As the waves moved down the truncated cone, the effect was to reproduce the omnidirectional soundwave, as with a cylinder that changed diameter. The considerable weight of the larger SUVs (such as the Chevrolet Suburban and the Ford Excursion) makes collisions with other, smaller cars much less dangerous for the SUV and much more dangerous for the car. This turned normal speaker driver design problems on their head; whereas the normal problem with designing a driver is how to keep the cone as stiff as possible (without adding mass), so that it moved as a unit and did not become subject to traveling waves on its surface, the Ohm drivers were designed so that the entire purpose of the electromagnetic driver was to generate traveling waves that traversed the cone from the electromagnet at the top downwards to the bottom. Also, the height of SUV headlights has been cause for complaint and distraction by drivers who find themselves dazzled at night by oncoming SUVs even when their lights are on low-beam settings. The Ohm model "F" speakers invented by Lincoln Walsh feature a single driver mounted vertically as though it were firing downwards into the top of the cabinet, but instead of the normal almost flat cone, having a very-much extended cone entirely exposed at the top of the speaker. Of course SUV's are not alone in posing this danger, as other vehicles such as vans and minivans similarly block drivers vision. Ribbon tweeters often emit sound that exits the speaker concentrated into a flat plane at the level of the listeners' ears; above and below the plane there is often less treble sound. This hazard is made worse by the nearly opaque window tinting which is found on the majority of SUVs currently sold.

Ribbon loudspeakers can be very fragile but recently designed planar tweeters have the metal film printed on a strong lightweight material for reinforcement. SUVs are often taller than other passenger vehicles, thus limiting another driver's vision of traffic in front of an SUV, and contributing to possible accidents involving sudden stops. The advantage of the ribbon loudspeaker is that the ribbon has very little mass; as such, it can accelerate very quickly, yielding good high-frequency response (although its shape is far from ideal). The size and design of SUVs can often be a hazard to other drivers. The electrical signal is applied to the ribbon which vibrates creating the sound. Aftermarket offerings also exist for interested buyers. The ribbon loudspeaker consists of a thin metal-film ribbon suspended between two magnets. Unfortunately, those tend to be pricey options and only a fraction of SUVs have them installed.

The stiffness moves self resonances upward in frequency. This is still rather new technology and is not fool-proof. The dome is used because it is an easily manufactured stiff structure - as anyone who has attempted to crush an egg the long way can attest to. Quite a few manufacturers try to remedy the problem by offering rear-view cameras or simple sensors that sound the alarm if the car is about to hit something. Perhaps contrary to intuition, making the moving component in the form of a dome rather than an inverted cone does not help to direct sound evenly in all directions. There are numerous cases where SUV owners have accidentally backed over their children and pets, or hit cars going down the parking aisle. Because the wavelength of high-frequency sound is short (approximately 15 mm at 20 kHz), tweeters must have a physically small moving component or they will create a "beam" of sound rather than sending sound omnidirectionally (as is usually desired). While it's a non-issue on the road, this makes backing out of a stall or a driveway more difficult and dangerous.

This design is typically used for tweeters and sometimes for mid-range speakers. Young children and cars behind the SUV may be completely invisible. For high frequencies, a variation on the common dynamic loudspeaker design uses a small dome as the moving part instead of an inverted cone. The back view is particularly restricted. Amar Bose of MIT spent many years trying to reproduce this spherical wavefront by constructing a one-eighth sphere covered in small drivers that would be situated in the corner of a room, thus mimicking one-eighth of a spherical wavefront emanating from that corner; in practice this idea never became workable, but Bose's experience with combining multiple small drivers in one loudspeaker cabinet gave rise to the popular Bose speakers which use multiple four-inch drivers, either to direct sound rearwards to reflect it from a wall behind the speakers, for home use, or to provide high power capacity when aimed directly at the listeners, for professional use. Also the size and design of SUVs leads to a restricted driver's view of the area immediately surrounding the vehicle. Several approaches have attempted to remedy this by approximating the sphere. This is in part because the collision of an SUV with a pedestrian tends to impact the chest, while the collision of a car with a pedestrian tends to impact the knees.

A point source or a sphere that varies in size with the amplitude of the desired pressure wave would avoid this problem of beam-formation but is generally physically impossible or impractical. An SUV hitting a pedestrian is about twice as likely to kill as a car at equal speed. This is especially a problem for high frequencies where the loudspeaker may be physically large compared to the wavelength of the sound being reproduced. However it is obvious that this advantage is only relative to other vehicles, and that one higher vehicle, while affording a better view for its own driver, will tend to obscure the view for all other road users, thus decreasing general road safety, and leading to frustration in other drivers. One problem with loudspeakers is that the essentially-planar form of most loudspeakers creates a soundwave that is somewhat directional, that is, the intensity of the sound produced varies depending on the listener's angle relative to the central axis of the speaker. A perceived benefit for SUV drivers is their higher seating: they have a better overview on the road, and therefore can react sooner to crossing children or incidents ahead. are mainly due to advantageous interactions with a particular speaker-room combination. [3].

It has been theorized by some of the audiophile world that the perceived differences in sound between amplifier/loudspeaker combinations are in fact only differences in their interaction with their environment, rather than absolute differences in sound quality; and similarly, that any perceived differences in speaker cables, past a minimum set of specifications regarding resistance, inductance, capacitance, etc. SUV drivers are also statistically less likely to wear their seatbelts. This interaction affects the speaker's electromechanical behavior and thus the load it represents to the amplifier, making it difficult to predict the sound a given system will produce in its intended environment without listening tests. [1] These figures may be confounded by variables other than the vehicles' inherent safety, for example the documented tendency for SUVs to be driven more recklessly (most sensationally perhaps, the 1996 finding that SUV drivers are more likely to drive drunk [2]). A complication is the interaction of the speaker with the listening environment. In 2004, the National Highway Traffic Safety Administration released figures showing that drivers of SUVs were 11 percent more likely to die in an accident than people in cars. and optionally,. It is clear, for example, that a tank, while "safer" for its own driver, would not contribute to public safety if driven on the highway.

Speaker specifications generally include:. It is also documented that many SUVs, while slightly reducing risk for people inside the SUV, substantially increase risk for the people outside the SUV (in other vehicles or on foot). In general a higher quality speaker will have a higher sensitivity rating, larger and or heavier magnet, and a higher X_max. Big and Bad, Gladwell.com. As shown in this example, sometimes the speaker with the lower sensitivity rating outputs a far higher amount of acoustic watt output. This and the massive size and weight of SUVs may lead to consumers' false perception of safety (Gladwell, 2004). However at full power may achieve 160+ decibels at 20% to 40% "true" efficiency. That you can look down is psychologically a very powerful notion".

80 to 86 dB/(W·m) (sensitivity efficiency of 0.01%). Rapaille, a psychological consultant to automakers (as cited in Gladwell, 2004), many consumers feel safer in SUVs simply because their ride height makes "[their passengers] higher and dominate and look down (sic). A few top of the line woofers have a very low "sensitivity" rating i.e. C. A higher X_max indicates that the driver can move a larger volume of air as power increases. According to G. In closed or small environments (such as cars or bedrooms) it is far more important to have a speaker with a high X_max (cone eXcursion maximum) as opposed to high (dB/(W·m)) rating. SUV safety concerns are compounded by a perception among some consumers that SUVs are safer for their drivers than standard autos; this perception is generally incorrect, although SUVs might provide more safety in a few situations.

above 140 decibels. Modern SUVs are usually designed to prevent rollovers on flat surfaces. The ratio of the sound output to the mass of the cone/coil combination grows significantly at high sound pressure levels i.e. This was also dramatically demonstrated in one Fifth Gear show using a Range Rover. This is partly due to a very high magnetic field and partly to a high amplitude displacement (speaker cone pumping in and out). In recent years, Consumer Reports has found a few unacceptable SUVs due to their rollover risk. Current state-of-the-art loudspeakers can approach efficiencies of 70% or higher. The high center of gravity of SUVs makes them more prone to rollover accidents (especially if the vehicle leaves the road or in emergency manoeuvres) than lower vehicles.

True or absolute efficiency is the ratio of "desired" output power divided by total input power. In fact, the Jeep Cherokee/Liberty (1984+) and Grand Cherokee (1993+) have used unibody construction from the start, and have hardly sacrificed ruggedness or offroad prowess in the process. As an example, a simple cheerleader's horn makes more sound output in the direction it is pointed than the cheerleader could by herself, but the horn did not improve or increase the cheerleader's total efficiency. However, some SUVs have designs based on unibody construction: the Ford Escape/Mazda Tribute, Lexus RX 330 (Motor Trend), RX 400h, Hyundai Santa Fe, and Acura MDX are some examples. From a technical standpoint "sensitivity" is not the absolute reference of efficiency. Many SUVs, on the other hand, are constructed in the traditional manner of light trucks: body-on-frame, which when negligently designed can provide a comparatively lower level of safety. Large horn loudspeakers that used to be used in cinemas, were very efficient by today's hi-fi speaker standards. The majority of modern automobiles are constructed by a method called unibody or monocoque construction, whereby a steel body shell absorbs the impacts of collisions in crumple zones.

The better the matching, the higher the efficiency. Safety is one common point of criticism. This is especially difficult at lower frequencies. In previous years, this deduction reached $102,000 and was the subject of much criticism. The main reason for this low efficiency is the difficulty of achieving proper impedance matching between the acoustic impedance of the drive unit and that of the air. However, the cost of both SUVs and automobiles is fully deductible over future years using normal depreciation. The remainder is converted to heat. This provides a slight tax incentive for businesses to purchase an SUV.

Only about 1% of the electrical energy put into the speaker is converted to acoustic energy. Small-business owners may deduct $10,610 of the cost of a passenger automobile. Loudspeakers are very inefficient transducers. In the United States, the so-called "SUV subsidy" (Section 179 depreciation deduction) allows small-business owners to deduct up to $25,000 of the cost of a vehicle with a Gross vehicle weight rating of over 6000 lb (2722 kg) from their income tax calculation. This is called the "sensitivity" rating. The explosive growth in SUV ownership has attracted a large amount of criticism, mainly of the risks to other road users and the environment, but also on the basis that the perceived benefits to the vehicle owner are illusory or exaggerated. The efficiency is measured as dB/(W·m)—decibels output for an input of one nominal watt measured at one metre from the loudspeaker usually on the axis of the speaker. Therefore, most SUV's have electronics to prevent a roll over.

The sound pressure level (SPL) that a loudspeaker produces is measured in decibels (dBSPL). One reason for this was that SUVs are more than 16 times more likely to "roll over" in an accident, and this has become more publicized in recent years. In all cases, replacement or full repair of the driver are the only options. In fact, SUV drivers were more likely to perish in an accident with a smaller car than is the driver of the other vehicle. The latter two typically happen when the amplifier dumps a large DC current into the speaker - a condition typical of a failing (or failed) amplifier. The most common reason for SUV popularity cited by owners was once the incorrect assertion that they confer a major advantage in a collision with regular cars. Electrical damage occurs when the voice coil burns out. "Betting the farm" on SUV popularity has caused General Motors to consider bankruptcy as SUVs are no longer popular vehicles to buy new.

A large DC fed to the woofer may cause twisting or deformation of the voice coil such that it rubs against the pole-pieces or magnet. Gas prices have now increased, leading to lower resale values for SUVs and far lower numbers of SUVs being purchased in the mid 2000s. In rare cases, a very loud signal may cause the coupling between the parts of the woofer to simply give way. After accounting for inflation, gas prices in the 1990s were cheaper on average than in any decade since the invention of the automobile. Physical damage occurs if the signal causes the woofer's cone displacement to exceed the safe X_mech limits for prolonged periods. One argument for SUV popularity in past years was cheap gasoline. Woofers will usually take a lot of power before burning out or suffering damage to their moving systems. As such, newer SUVs have lower ground clearance and more comfortable suspensions.

Most woofers (and mid-ranges) can easily take up to 1.5 times or more power than what they are rated for - however this is dependent on the particular driver and the duration of the abuse or overload. Newer SUVs take into account the prevailing usage patterns where the SUV is not expected to ever see any significant offroad usage. A badly clipping amplifier may also damage the tweeter despite a crossover, since a clipped waveform generates high-frequency harmonics which can contain sufficient power to heat up the tweeter's voice coil. In time, the public's dislike of truck-like characteristics in SUVs brought about a more-refined current crop of SUVs. Thus, feeding a low frequency (or a DC) signal to a tweeter even though electrically it may be within the tweeter's specification may cause permanent damage to the tweeter. Still, SUVs are, in general, more expensive than sedans. Thus a tweeter rated for 50 W is meant to be used with a 50 W amplifier only if the signals below the tweeter's lower operating frequency are filtered out. Historically, their simple designs and often outdated technology (by passenger car standards) often made the vehicles cheaper to make than comparably-priced cars.

Tweeters are usually designed (and rated) keeping in mind that a typical music signal doesn't contain a lot of power or energy at the higher end of the audio spectrum. In the late 1990s and early 2000s, vehicle manufacturers sold the image of SUVs very effectively, with per-vehicle profits substantially higher than other automobiles. The tweeters are usually the first to go under circumstances of abuse, since they have the lightest voice coil made of thin wire which easily melts if the temperature rises excessively. Undoubtedly, though, some of their success is due to their supposed "powerful image", a substantial factor for many people who might more logically choose a more economical and cheaper car, van, station wagon, or hatchback. However they do have limits and exceeding them by a large factor almost always causes permanent damage. Critics argue that only a fraction of SUVs will be used for heavy duty work (and many SUVs have surprisingly low load capacities) that can't be done with a regular car. Loudspeakers are rugged devices and can take some amount of abuse. Additionally, most large SUVs have far greater towing capacities than conventional cars, and in the case of trailerable boats have superior abilities to launch and retrieve those boats from slippery boat ramps (and, indeed, from many places where no made ramp exists).

Some of the issues in speaker design are lobing, phase effects, off axis response and time coherence. Owners pointed to their large, comfortable cabins (which approach the passenger and equipment-carrying capabilities of minivans), safety, and the recreational possibilities of the vehicles. Speaker designers will use an anechoic chamber (essentially a room with soundproofing that inhibits any reverberation or echo) to ensure the speaker will perform the way it is intended to. SUVs became popular in US for a variety of reasons. Adjusting a design is done with instruments and with the ear. In the mid 2000s, their popularity has waned considerably. The nature of speaker design is considered both an art and science. SUVs were immensely popular in the late 1990s and early 2000s.

The inverse sound waves and external noise cancel each other out and produce near silence. Modified SUVs also take part in races, most famously in the Paris-Dakar Rally, and the Australian Safari. The headphones produce the inverse sound waves of the external noise. at least, many 4WD clubs have been formed for this purpose. A similar effect is used in sound-cancelling headphones. In Australia, China, Europe, South Africa and the U.S. The second most noticed will be an unsettling feeling. Some private SUV owners do indeed take their vehicles off the road to explore places otherwise unreachable by vehicle or for the sheer enjoyment of the driving.

The most prominent effect to the untrained ear will be a loss of bass response. These newer SUVs have more in common with modern mini-vans than older SUVs, as such the term SUV now follows more closely with Sport Utility Van than Sport Utility Vehicle. This won't cause silence because reflections from surfaces diminish the effect somewhat but resulting in a major loss of sound quality. Consequently, more modern SUVs often come laden with luxury features and some crossover SUVs, such as the BMW X5, the Acura MDX, and the Toyota RAV4, have adopted lower ride heights and car chassis to better reflect their typical use (overwhelmingly, for normal on-road driving). This type of wiring error creates inverse sound waves which cancel out (to a degree) the sound of the other speaker. However, in the last 25 years, and even more in the last decade, they have become popular with urban buyers. In this case, any motion one cone makes will be 180 degrees opposite the other. Descended from commercial and military vehicles such as the Jeep and Land Rover, they have been popular for many years with rural buyers due to their off-road abilities.

If both sets of wires for left and right (in a stereo setup) are not connected in phase, the speakers will be out of phase from each other. SUVs do look large, and their height inconveniences other drivers, and even though many SUVs are wider or longer than most other cars, they are not necessarily so. All speakers have two wires that must connected from the source of the signal (the amplifier or receiver) to the speaker's input terminals in correct polarity, or phase. SUV's are criticized in the Netherlands for being too large as well and some environmentalists are pushing local governments to deny SUV users parking spaces. The Tapered Quarter Wave Pipe (TQWP) is an example of a combination of transmission line and horn effects. In The Netherlands they are often called "PC Hooft-tractoren" after Amsterdam's most exclusive shopping street. This compromise is extremely attractive and used 90 percent of the time in bass horns. In Australia, particularly Victoria, they are referred to as "Toorak Tractors".

This reduces the theoretical output by 3, but it is still maybe 5 times the output of a simple speaker in a box (no horn). In New Zealand they are occasionally called "Fendalton tractors" or "Remuera tractors" after the higher priced suburbs in Christchurch and Auckland respectively. This means instead of using the perfect large size length of say 10ft, they cut it off at a length of say 3.3ft. In the UK they are occasionally known as jeeps or Land Rovers no matter what make they actually are, although the increasing prevalence of these vehicles in recent years has decreased this colloquial usage. To minimize the size, some bass horns are designed as a "modified" or "cut" horn. In southern England, SUVs, excluding farm vehicles such as Land Rovers, are often referred to in derogatory terms as "Soft-Roaders" or "Chelsea tractors", coined by London Mayor, Ken Livingstone. Despite this, they are used about 70 to 90 percent of the time in large stadiums or arenas. "Utility", or "Ute", refers to an automobile with a flatbed rear or pick-up, typically seating two passengers and is often used by tradesmen, and is typically not a 4WD vehicle.

Designs that use horn woofers occupy a large space, and are heavy. In Australia, the automotive industry and press have recently adopted the term SUV in place of four wheel drive in the description of vehicles and market segments. Some low frequency horns employ a folded horn design to conserve space. distinction between cars and "light trucks" is not used. For the bass or low-frequency region the size of the horn becomes exceedingly large and impractical (3ft x 2ft x 2ft, for example). They are classified as cars in countries such as the UK where the U.S. This type has a very high efficiency and reasonably small size for reproducing mid to high frequencies. Outside of North America and India these vehicles are known simply as four-wheel-drives often abbreviated to "4WD" or "4x4".

A horn (like a cheerleader horn) is an enclosure which has a flare or cone shaped structure attached to the front of the driver (speaker). In countries where fuel is more expensive, buyers often opt for diesel engines, which have better fuel efficiency (and diesel fuel itself is often much cheaper). The baffle dimensions are chosen to get the desired response, with larger dimensions giving a lower frequency before the front and rear waves combine and cancel. The design also allows for a large engine compartment, and many SUVs have large V-6 or V-8 engines. A rectangular cross-section is more common than a circular one since it is much easier to fabricate in folded form than a circular cross-section. In higher-end models, all four wheels can provide motion ("drive"), unlike the majority of automobiles in which only the front or rear wheels provide drive. The baffle may be folded in order to conserve space. Typical to a light truck platform, SUVs have higher seating than a station wagon and a suspension designed for giving ground clearance for off-road driving.

A dipole enclosure in its simplest form is a driver located on a flat baffle. In contrast, station wagons are typically wider than they are tall, and minivans are taller than they are wide. [4]. SUVs are typically taller, though, with a roughly square cross section. The payoff is an extended low end response and a characteristic sound that's appealing to many. SUVs were traditionally derived from light truck platforms, but have developed to have the general shape of a station wagon. Transmission lines tend to be larger than the other systems, due to the size and length of the line required by the design. .

The transmission line system is a waveguide system in which the guide reverses the phase of the driver's rear output, thereby reinforcing the frequencies near the driver's F_s. A new category, the crossover SUV uses car components for lighter weight and better economy. PR's do add considerable cost to the system, however. In more recent years, the term has also grown to encompass vehicles with similar size and style that are marketed as sport utility vehicles, but which do not actually incorporate substantial off-road features. Due to the lack of vent turbulence and vent pipe resonances, many prefer the sound of PR's to reflex ports. A sport utility vehicle (SUV) or off-roader, known in some countries as a four wheel drive, (often abbreviated to 4WD or 4x4 - pronounced "four-by-four") or soft roaders, is a type of passenger vehicle which combines the load-hauling and passenger-carrying capacity of a large station wagon or minivan with features designed for off-road driving. Passive radiators add a complication to vented systems which causes a notch in frequency response at the PR's free air resonant frequency and this causes a steeper rolloff below the drone's tuning frequency Fb and poorer transient response than standard vented loudspeakers. high rolling resistance due to all terrain tires (even worse if low pressure is needed offroad) and high vehicle mass driving the rolling resistance where μ_roll stands for the rolling resistance factor and m_vehicle for the vehicle mass.

Passive radiators are tuned by their mass (Mmp) and the way their compliance interacts with the compliance of the air in the box. wind). They are also used to eliminate port turbulence and reduce power compression caused by high velocity airflow in ports. high crossectional area causing very high drag losses especially when driven at high speed where F stands for the force, A_cross for the crossectional area of the vehicle, ρ_air for the density of the air and v_air for the relative velocity of the air (incl. Passive radiators are used primarily to tune small volumes to low frequencies, where a port would need to be very long. high parasitic masses (compared to the average load) causing high energy demand in transitional operation (in the cities) where P stands for power, m_vehicle for the vehicle mass, a for acceleration and v for the vehicle velocity. Sometimes a passive radiator (PR) or drone, similar to a speaker driver but without an electrically activated voice coil, is used instead of a reflex port.

This enclosure is considerably harder to design and tends to be driver-specific. If the enclosure on each side of the woofer has a port in it then the enclosure yields a 6^th order band-pass response. The dividing wall between the chambers has the driver mounted on it and the panel opposite to it (or the chamber into which the driver faces) has a port. In its simplest form it has two chambers.

A 4^th order bandpass is really just the same as a vented box where the contribution from the driver is trapped in a sealed box which modifies the resonance of the driver. This enclosure is the most common as it lends itself to small size and reasonable bass. Reflex ports are tuned by amount of mass within the vent, using appropriate diameter and length to reach this point. The interior of such enclosures are also often lined with fiberglass matting for absorption.

Other types of enclosures attempt to improve the low frequency response or overall efficiency of the loudspeaker by using various combinations of reflex ports or passive radiating elements to transmit the energy from the rear of the speaker to the listener; these enclosures may also be referred to as vented/ported enclosures, bass reflex, transmission lines (see below). The drawback of these speakers is their low efficiency, due to the loss of the power absorbed inside the cabinet. In this case, the true suspension of the driver's cone is the air trapped inside the box which acts as a spring with very close to ideal behavior rather than the mechanical suspension of the speaker driver, which for this application must be very weak, just strong enough to keep the cone centered in the absence of any signal. The box is typically designed with a very small rate of leakage so that internal and external pressures can slowly equilibrate over time, allowing the speaker to adjust to changes in barometric pressure or altitude.

The closed-box or 'acoustic suspension' enclosure, rather than using a large box to avoid the effect of the internal air pressure, uses a smaller, tightly sealed box. The box is usually filled loosely with foam, pillow stuffing, fiberglass, or other wadding, converting the speaker's thermodynamic properties from adiabatic to isothermal, and giving the effect of a larger cabinet. The box must be large enough that the internal pressure caused when the driver cone moves backwards into the cabinet does not rise high enough to affect this. The designer trades off bass response for flatness; the larger the resonant peak in the bass, the lower the speaker will seem to reproduce, but the more over-emphasized the resonant frequency will be.

The loudspeaker driver's mass and compliance, i.e. the stiffness of the suspension of the cone, determines the resonant frequency and damping properties of the system, which affect the low-frequency response of the speaker; the response falls off very sharply below the cabinet resonant frequency (Fcb). A variation on the 'open baffle' is to place the loudspeaker in a very large sealed box. The most common enclosure types are listed below. For the purposes of this type of analysis, each enclosure has a loudspeaker topology.

Enclosures used for woofer and subwoofer are applications that can be adequately modelled in the low frequency range (approximately 100–200 Hz and below) using acoustics and the lumped component model. The Acoustic Center of the driver, or physical position of each driver's voice coil, dictates the amount of rearward offset to time-align the drivers. Sometimes the differences in reaction time of the different size drivers is addressed by setting the smaller drivers further back, by leaning or stepping the front baffle, so that the resulting wavefront from all drivers is coherent when it reaches the listener. Diffraction problems are addressed in the shape of the enclosure; avoiding sharp corners on the front of the enclosure for instance.

Home experimenters have designed speakers built from concrete sewer pipes for similar reasons. The speaker manufacturer Wharfedale has addressed the problem of cabinet resonance by using two layers of wood with the space between filled with sand. Problems with resonance are usually reduced by increasing enclosure rigidity, added internal damping and increasing the enclosure mass. Enclosures play a significant role in the sound production, adding resonances, diffraction, and other unwanted effects.

However, for many purposes this is impractical and the enclosures must use other techniques to maximize the output of the loudspeaker (called loading). An 'open baffle' loudspeaker is an approximation to this - the transducer is mounted on a simple board of size comparable to the lowest wavelength to be reproduced. Thus the rear soundwaves cannot cancel the front soundwaves. The ideal mount for a loudspeaker would be a flat board of infinite size with infinite space behind it.

The major role of the enclosure is to prevent the out-of-phase sound waves from the rear of the speaker combining with the positive phase sound waves from the front of the speaker, which would result in interference patterns and cancellation causing the efficiency of the speaker to be compromised, particularly in the low frequencies where the wavelengths are large enough that interference will affect the entire listening area. A loudspeaker is commonly mounted in an enclosure (or cabinet). When used with speakers that do not reproduce low frequencies well, a subwoofer will often be configured to reproduce both the LFE channel and all other bass in the system, the latter being referred to as "bass management". This is because most full-range speakers are incapable of delivering the acoustic power required by the LFE in movies or in some cases, music.

When teamed with a modern surround sound receiver and full range speakers, they are typically driven with the specific LFE (low frequency effects) output channel (the ".1" in 5.1, 6.1, or 7.1 specifications) provided by the receiver. Amplified subwoofers frequently accept both speaker-level and line-level audio signals. Extended periods of high volume bass can cause items throughout a room to "walk" on a flat surface until they fall off. A subwoofer's powerful bass can often cause items in the room or even the structure of the room itself to vibrate or buzz.

Placing it in the corner of a room may produce louder bass sounds. It can instead be hidden out of sight. For the same reason, the subwoofer does not need a special placement in the sound field (for example, centered between the Left Front and Right Front speakers). Because of this phenomenon, it is usually satisfactory to provide just a single subwoofer no matter how many individual channels are being used for the full-spectrum sound.

Localization starts to happen above the 150 Hz point. The very long wavelength of the very low frequency bass sounds reproduced by the subwoofer usually makes it impossible for the listener to localize the source of these sounds. Subwoofers often contain integrated power amplifiers that may incorporate sophisticated feedback mechanisms to assure the least distortion of the reproduced bass acoustic waveform. Because the range of frequencies that must be reproduced is quite limited, the design of the subwoofer is usually quite simple, often consisting of a single, large, down-firing woofer enclosed in a cubical "bass-reflex" cabinet.

A typical subwoofer only reproduces sounds below 120 Hz (although some subwoofers allow a choice of the cross-over frequency). This speaker (and its enclosure) is referred to as a subwoofer. Modern speaker systems often include a single speaker dedicated to reproducing the very lowest bass frequencies. A subwoofer driver is a woofer optimised for the lowest range of the audio spectrum.

A whizzer is a small, light cone attached to the woofer's apex around the dust cap. These employ an additional cone called a whizzer to extend the high frequency response. A full-range speaker is designed to have as wide a frequency response as possible. A tweeter is a loudpeaker which is capable of reproducing the higher end of the audio spectrum, usually from about 1 kHz to 20 or perhaps 35 kHz.

Mid-ranges typically appear where large (>16 cm or 8") woofers are used for the bass end of the audio spectrum. These are used when the bass driver (or woofer) is incapable of covering the mid audio range. The distinction between woofers and mid-ranges is blurred however since many woofers can operate up to 3 kHz. A mid-range loudspeaker, also known as a squawker is designed to cover the middle of the audio spectrum, typically from about 200 Hz to about 4-5 kHz.

The frequency range varies widely according to design and hence while some woofers can cover the audio band from 50 Hz to 3 kHz, yet others may only work up to 1 kHz. A woofer is a loudspeaker capable of reproducing the bass frequencies. [3]. However a loudspeaker of say, a rated impedance of 8Ω/100W can easily overload an amp designed purely with a resistive load of 8Ω/100W as a target.

A typical amplifier is most usually quoted for a given power into a resistive load. It is a combination of resistive, capacitive, inductive as well as mechanical effects. A dynamic loudspeaker presents a complex load to the amplifier as opposed to a pure resistance. The weight and damping of the cone in a dynamic speaker should be appropriate for the characteristics of the rest of the driver and enclosure in order to produce accurate sound.

Despite marketing claims, lighter and more rigid cones do not always sound better. Tweeters are subject to a unique set of variables and parameters; their design and construction is extremely variable. Generally, larger and more powerful magnets are associated with higher quality speakers. The size and type of magnets can also differ.

Baskets must be designed in order to preserve rigidity and are typically cast or stamped metal, although injection-molded plastic baskets are becoming much more common in recent years. Driver cones may be constructed of a variety of materials, including paper, metal, various polypropylenes, and kevlar. When a multi-frequency signal is applied, the complex vibration results in reproduction of the applied signal as an audio signal. The coil and the permanent magnet interact with magnetic force which causes the coil and a semi-rigid cone (diaphragm) to vibrate and reproduce sound at the frequency of the applied electrical signal.

When an electrical signal is applied, a magnetic field is induced by the electric current in the coil which becomes an electromagnet. The parts are held together by a chassis or basket. A typical suspension system includes the 'spider', which is at the apex of the cone, often of 'concertina' form; and the 'surround', which is at the base of the cone. In addition to the magnet, voice coil, and cone, dynamic speakers usually also include a suspension system to provide lateral stability and make the speaker components return to a neutral point after moving.

One magnetic pole is outside the coil, whilst the other is inside the voice coil. The gap is also where the magnetic field is concentrated. The coil is oriented coaxially inside the gap made with a permanent magnet. A "gap" is a small circular hole, slot or groove which allows the voice coil and cone to move back and forth.

The traditional design is a semi-rigid paper fibre cone and a coil of fine wire (usually copper), called the voice coil attached to the apex of the cone. Additional improvements to loudspeaker technology occurred in the 1970s, with the introduction of higher temperature adhesives, improved permanent magnet materials, and improved thermal management. Polypropylene and aluminium are also used as diaphragm materials. For Example, Paper cones (or doped paper cones, where the paper is treated with a substance to improve its performance) are still in use today, and can provide good performance.

acoustic suspension) and changes in materials used in the actual loudspeaker, led to audible improvements. Developments in cabinet technology (e.g. The quality of loudspeaker systems until the 1950s was, to modern ears, very poor. This winding usually served a dual role, acting also as a choke coil filtering the power supply of the amplifier which the loudspeaker was connected to.

The coil of the electromagnet is called a field coil and is energized by direct current through a second pair of terminals. These first loudspeakers used electromagnets because large, powerful permanent magnets were not freely available at reasonable cost. Voigt produced the first effective full range unit in 1928, and he also developed what may have been the first system designed for the home, although using electromagnets rather than permanent magnets. There is some controversy in that an application was made earlier by the Briton Paul Voigt but not granted until later.

Kellogg. Rice and Edward W. The moving coil principle was patented in 1924 by two Americans, Chester W. [2].

The modern design of moving-coil loudspeaker was established by Oliver Lodge in England (1898). This was soon followed by an improved version from Ernst Siemens in Germany and England (1878). Alexander Bell patented the first loudspeaker as part of his telephone in 1876. However, the first documented ^[1] device that might fit this description was created in 1881.

Nikola Tesla is believed to have put electrically charged carbon dust in a cup-shaped device to create the first telephone loudspeaker. . The loudspeaker is the most variable element in an audio system, and is responsible for marked audible differences between systems. The term loudspeaker is used to refer to both the device itself, and a complete system consisting of one or more loudspeaker drivers (as the individual units are often called) in an enclosure.

A loudspeaker, or simply speaker, is an electromechanical transducer which converts an electrical signal into sound. In SDDS, 7.1 is the same as 5.1 but adding center-left and center-right speakers in the front of the listener for better audio positioning. 7.1 channel sound in home theater is identical to 6.1 except that it has left and right rear speakers. 6.1 channel sound is similar to 5.1 but there is an added center rear channel.

This is usually achieved by an amplifier setting of 'large' or 'small' defining the speaker type. This speaker can reproduce the bass frequency from all the main channels or may only do so for those speakers incapable of doing so. A subwoofer (which is counted as ".1" channel because of the narrow frequency band that it reproduces). Left and right surround speakers.

Left, center, and right front speakers. This requires: