Author by: John Eargle Language: en Publisher by: Springer Science & Business Media Format Available: PDF, ePub, Mobi Total Read: 37 Total Download: 685 File Size: 46,9 Mb Description: The second edition of Loudspeaker Handbook follows the same general outlines as the highly successful first edition and has been augmented and updated in many areas of technology. Most notable are the developments in large-scale, programmable line arrays, distributed mode loudspeakers, and ultrasonic-based audio transduction. Additionally, the core chapters on low frequency systems, system concepts, and horn systems have been expanded to include both more analytical material and a richer array of examples. Much of the success of the first edition has been due to its accessibility both to loudspeaker engineers and to lay technicians working in the field - a point of view the author maintains in the present work. A full understanding of the underlying technology requires a fairly rigorous engineering background through the second year of professional study. At the same time, the generous use of graphs, with their intuitive thrust, will be useful to all readers. Loudspeaker Handbook, Second Edition continues to be appropriate for use in courses at the undergraduate senior level, for graduate students, and for professionals in audio and acoustical engineering.

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Author by: John Borwick Language: en Publisher by: CRC Press Format Available: PDF, ePub, Mobi Total Read: 33 Total Download: 831 File Size: 43,5 Mb Description: Written by a team of experts, the Loudspeaker and Headphone Handbook provides a detailed technical reference of all aspects of loudspeakers and headphones: from theory and construction of transducer drive units and enclosures, to such practical matters as construction, applications in rooms, public address, sound reinforcement, studio monitoring and musical instruments. Loudspeaker measurements and subjective evaluation are treated in equal detail and headphones are discussed comprehensively. This third edition takes account of recent significant advances in technology, including: the latest computer-aided design systems digital audio processing new research procedures the full range of loudspeakers new user applications. Author by: David Havelock Language: en Publisher by: Springer Science & Business Media Format Available: PDF, ePub, Mobi Total Read: 31 Total Download: 506 File Size: 47,7 Mb Description: The Handbook of Signal Processing in Acoustics brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of the subject. It brings the key issues from both acoustics and signal processing into perspective and is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics. Author by: Gary Davis Language: en Publisher by: Hal Leonard Corporation Format Available: PDF, ePub, Mobi Total Read: 78 Total Download: 142 File Size: 50,5 Mb Description: (Yamaha Products).

Sound reinforcement is the use of audio amplification systems. This book is the first and only book of its kind to cover all aspects of designing and using such systems for public address and musical performance. The book features information on both the audio theory involved and the practical applications of that theory, explaining everything from microphones to loudspeakers.

This revised edition features almost 40 new pages and is even easier to follow with the addition of an index and a simplified page and chapter numbering system. New topics covered include: MIDI, Synchronization, and an Appendix on Logarithms. Author by: R.

Marston Language: en Publisher by: Newnes Format Available: PDF, ePub, Mobi Total Read: 48 Total Download: 331 File Size: 43,6 Mb Description: Newnes Circuits Manuals and Users' Handbooks by Ray Marston cover a wide range of electronics subjects in an easy-to-read and non-mathematical manner, presenting the reader with many practical applications and circuits. They are specifically written for the practising design engineer, technician, and the experimenter, as well as the electronics student and amateur. The ICs and other devices used in the practical circuits are modestly priced and readily available types, with universally recognized type numbers. Author by: Thomas Rossing Language: en Publisher by: Springer Science & Business Media Format Available: PDF, ePub, Mobi Total Read: 63 Total Download: 156 File Size: 41,6 Mb Description: This is an unparalleled modern handbook reflecting the richly interdisciplinary nature of acoustics edited by an acknowledged master in the field. The handbook reviews the most important areas of the subject, with emphasis on current research. The authors of the various chapters are all experts in their fields.

Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, including computer recognition and synthesis of speech, physiological acoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. An accompanying CD-ROM contains audio and video files. Author by: James P. Cowan Language: en Publisher by: John Wiley & Sons Format Available: PDF, ePub, Mobi Total Read: 52 Total Download: 471 File Size: 51,9 Mb Description: Because environmental acoustics has a complex mathematical basis, it is often difficult to determine whether acoustical recommendations are valid. Handbook of Environmental Acoustics simplifies this decision–making process and provides easy–to–follow explanations of acoustic terminology, noise control design, and regulatory noise issues. Author by: Malcolm J.

Crocker Language: en Publisher by: John Wiley & Sons Format Available: PDF, ePub, Mobi Total Read: 12 Total Download: 748 File Size: 52,6 Mb Description: Acoustical engineers, researchers, architects, and designers need a comprehensive, single-volume reference that provides quick and convenient access to important information, answers and questions on a broad spectrum of topics, and helps solve the toughest problems in acoustical design and engineering. The Handbook of Acoustics meets that need. It offers concise coverage of the science and engineering of acoustics and vibration. In more than 100 clearly written chapters, experts from around the world share their knowledge and expertise in topics ranging from basic aerodynamics and jet noise to acoustical signal processing, and from the interaction of fluid motion and sound to infrasound, ultrasonics, and quantum acoustics. Author by: John M.

Eargle Language: en Publisher by: Springer Science & Business Media Format Available: PDF, ePub, Mobi Total Read: 68 Total Download: 340 File Size: 47,9 Mb Description: John Eargle's 4th edition of The Handbook of Recording Engineering is the latest version of his long-time classic hands-on book for aspiring recording engineers. It follows the broad outline of its predecessors, but has been completely recast for the benefit of today's training in recording and its allied arts and sciences. Digital recording and signal processing are covered in detail, as are actual studio miking and production techniques -- including the developing field of surround sound. As always, the traditional topics of basic stereo, studio acoustics, analog tape recording, and the stereo LP are covered in greater detail than you are likely to find anywhere except in archival references. This book has been completely updated with numerous new topics added and outdated material removed. Many technical descriptions are now presented in Sidebars, leaving the primary text for more general descriptions. Handbook of Recording Engineering, Fourth Edition is for students preparing for careers in audio, recording, broadcast, and motion picture sound work.

It will also be useful as a handbook for professionals already in the audio workplace.

How a horn loudspeaker works. (A) (B) horn A horn loudspeaker is a or loudspeaker element which uses an to increase the overall efficiency of the driving element(s). A common form (right) consists of a which produces sound waves with a small metal diaphragm vibrated by an, attached to a horn, a flaring duct to conduct the sound waves to the open air. Another type is a driver mounted in a which is divided by internal partitions to form a zigzag flaring duct which functions as a horn; this type is called a folded horn speaker. The horn serves to improve the coupling efficiency between the and the air. The horn can be thought of as an 'acoustic ' that provides between the relatively diaphragm material and the less-dense air.

The result is greater acoustic output power from a given driver. The narrow part of the horn next to the driver is called the 'throat' and the large part farthest away from the driver is called the 'mouth'. The angular coverage () of the horn is determined by the shape and flare of the mouth. Unlike cone speakers, horn speakers usually have rectangular apertures, with the width tailored for proper horizontal coverage angle, and height tailored for proper vertical coverage angle.

A major problem of horn speakers is that the radiation pattern varies with frequency; high frequency sound tends to be emitted in narrow beams with poor off-axis performance. Significant improvements have been made, beginning with the ' horn invented in 1975.

The main advantage of horn loudspeakers is they are more efficient; they can typically produce 10 times (10 ) more sound power than a cone speaker from a given amplifier output. Therefore horns are widely used in,, and sound systems for large venues like theaters, auditoriums, and sports stadiums. Their disadvantage is that their is more uneven because of peaks, and horns have a cutoff frequency below which their response drops off. To achieve adequate response at bass frequencies horn speakers must be very large and cumbersome, so they are more often used for midrange and high frequencies. The first practical loudspeakers, introduced around the turn of the 20th century, were horn speakers.

Due to the development in recent decades of more efficient cone loudspeakers, which have a flatter frequency response, use of horn speakers in high fidelity audio systems has declined. Various horn prototypes in the lab of, 's chief horn designer. From about 1888 to 1925, a horn was used to concentrate sound waves in the process of recording onto, and another horn was used to amplify the recordings during playback. Acoustic horns convert large pressure variations with a small displacement area into a low pressure variation with a large displacement area and vice versa. It does this through the gradual, often increase of the cross sectional area of the horn.

The small cross-sectional area of the throat restricts the passage of air thus presenting a high to the driver. This allows the driver to develop a high pressure for a given displacement. Therefore the sound waves at the throat are of high pressure and low displacement. The tapered shape of the horn allows the sound waves to gradually decompress and increase in displacement until they reach the mouth where they are of a low pressure but large displacement.

A modern electrically driven horn loudspeaker works the same way, replacing the mechanically excited diaphragm with a dynamic or loudspeaker. Modern horn designs typically feature some form of conical, exponential or taper. Roughly speaking, the slower the flare rate, the deeper and lower frequencies the horn will reproduce for a given length of horn. For example, a horn area growth rate of 30% per foot will allow reproduction down to about 30; 10 times area per foot provides midrange reproduction; 100 times area per foot is used in high frequency horns. Modern high output horns also make the throat area of the horn smaller than the diaphragm area.

This is called the 'loading' or 'compression' ratio of the horn. The compression ratio is the diaphragm area divided by the throat area. Typically for bass and midrange frequency the compression ratio is from low compression (1.5 to 1) to normal compression (2 to 1) to high compression (3.5 to 1). High frequency compression drivers sometimes have compression ratios as high as 10 to 1.

The higher the compression the greater the horn's ability to properly couple the diaphragm to the air at the horn's mouth, increasing efficiency, until the compression ratio is so high that it actually begins to impede cone motion. At this point the maximum sound output power from the horn (at a given distortion) will be reduced. To demonstrate this at an extreme, place a cone face down on a rigid surface.

The compression ratio will be very high, however sound output from the back of the speaker will be quite low. Horn technology history. Francis Barraud's original photograph of looking into an cylinder phonograph The physics (and mathematics) of horn operation were developed for many years, reaching considerable sophistication before WWII. The most well known early horn loudspeakers were those on mechanical, where the record moved a heavy metal needle that excited vibrations in a small metal that acted as the driver for a horn.

A famous example was the horn through which the dog heard 'His Master's Voice'. The horn improves the loading and thus gets a better 'coupling' of energy from the diaphragm into the air, and the pressure variations therefore get smaller as the volume expands and the sound travels up the horn. This kind of mechanical impedance matching was absolutely necessary in the days of pre-electrical sound reproduction in order to achieve a usable sound level. A collapsible cone horn with removable flared bell. This horn was patented in 1901 for playback The is the oldest and simplest acoustic horn and, as the, is still used by cheerleaders and lifeguards as a passive amplifier of their voices. Because the conic section shape describes a portion of a perfect sphere of radiated sound, cones have no phase or amplitude distortion of the wavefront.

The acoustic loading provided by the cone does not extend the low frequency limit low enough for most modern purposes, with its output energy markedly less than later designs throughout the bottom two octaves of the cone's intended frequency range. A three-way loudspeaker from the late 1970s employing a different exponential horn at each bandpass The horn has an acoustic loading property that allows the speaker driver to remain evenly balanced in output level over its frequency range. The benefits of the design were first published by C.R. Slepian in 1924 for the (AIEE). A major drawback is that the exponential horn allows for a narrowing of the radiation pattern as frequency increases, making for high frequency 'beaming' on axis and dull sound off axis.

Another concern is that a throat of small diameter is needed for high efficiency at high frequencies but a larger throat is best for low frequencies. A common solution is to use two or more horns, each with the appropriate throat size, mouth size and flare rate for best performance in a selected frequency range, with sufficient overlap between the frequency ranges to provide a smooth transition between horns.

Another solution tried in the late 1930s by of was to use multiple exponential flare rates, either by connecting increasingly larger horns in series or by subdividing the interior of a single horn. Exponential horns continue to be used by some designers, and in some applications. Multicell horn models from a 1978 product catalog A number of symmetrical, narrow dispersion, usually exponential horns can be combined in an array driven by a single driver to produce multicell horns. Patented in 1936 by Edward C. Wente of, multicell horns have been used in loudspeakers since 1933 to address the problem of directivity at higher frequencies, and they provide excellent low frequency loading.

Their directional control begins to beam both vertically and horizontally in the middle of their target frequency range, narrowing further at high frequencies with level changes as great as 10 dB between lobes. Multicell horns are complex, difficult to fabricate and thus have a higher associated expense. They persisted in applications for many years because, even with their faults, they sounded relatively good. The revolutionary coaxial driver, the 601 and 604, used a multicell horn for its high frequency component from 1943 to 1998.

A model 2397 diffraction horn from 1978. The 2397 contained internal sectoral vanes which divided the throat into six exponential sections Radial horns have two surfaces based on an exponential flare rate, and two straight walls that determine the output pattern. The radial horn exhibits some of the beaming of the exponential horn. Altec sectoral horns were radial horns with vanes placed in the mouth of the horn for the stated purpose of pattern control. For ease in mounting to loudspeaker cabinets, flat front radial horns have been used, for instance by in their SQ 90 high-frequency horn.

's diffraction or 'Smith' horn was a variation on the radial design, using a very small vertical dimension at the mouth as a method of avoiding the mid-range horizontal beaming of radial horns that have a larger vertical dimension at the mouth. The diffraction horn has been popular in monitor designs and for near-field public address applications which benefit from its wide horizontal dispersion pattern. Counterintuitively, the narrow vertical dimension provided for an expansive vertical output pattern approaching 90° for frequencies of a wavelength equal to the narrow vertical dimension. A very small version of the diffraction horn was designed in 1991 into the JBL model 2405H Ultra-High Frequency Transducer, yielding a 90° x 35° output pattern at 20 kHz.

Tractrix The horn is very similar in many respects to the exponential horn and has gained adherents among horn enthusiasts and consumers. It uses a curve formula derived by assuming that a tangent to any point on the horn's inner curve will reach the central axis of the horn with a line segment of set length. At the mouth, the tangent line segment becomes perpendicular to the axis and describes the radius of the mouth. This horn concept was studied by Paul G.A.H. Voigt in the mid-1920s and patented in 1927.

The size of the tractrix horn is generated by specifying the desired low frequency 'cutoff' or limit which will determine the mouth diameter. Two incremental improvements over the exponential horn include slightly better support for low frequency extension and a somewhat broader high-frequency coverage pattern. Constant directivity. Don Keele's first constant directivity horn patent was assigned to in 1978 In May 1975, to address problems of beamwidth changing at different frequencies, of introduced a hybrid horn with an exponential expansion rate near the throat followed by a conical expansion section and ending with a rapidly flaring flange at the mouth. The flange at the mouth solved some remaining problems with lobing at higher frequencies.

Don Keele specified in one version of his design a wider horizontal flare for pattern control appropriate to public address purposes. Keele's paper set forth the relationships between mouth size, frequency and coverage angle, providing a basis for many future developments of horn design. One problem found with constant directivity horns is that the horizontal coverage pattern cannot be narrowed without making the vertical coverage pattern too small to be useful. Mantaray Subsequent to Keele's work and using his principles, and Mark S. Ureda of Altec designed a strikingly different hybrid horn displaying constant directivity traits, the horizontal diffraction or 'Mantaray' horn. Virtualbox Additions Windows 98 Download For Free.

The Mantaray separated desired vertical coverage pattern from horizontal, making it possible to design horns for a variety of coverage patterns. The Mantaray shape starts with a vertically oriented JBL-style diffraction horn leading into a conical waveguide (earliest designs) or a square or rectangular horn with four planar sides. For midrange beaming control, the outer mouth was expanded further with a short, flared flange in the Keele style, or with added planar sides of a greater flare angle. Low frequency efficiency was not as pronounced as the constant directivity design.

Unlike previous designs, the apparent apex, the focal point of pattern dispersion, was not the same for every frequency, making for an ellipsoidal wavefront rather than spherical. Because of this, the Mantaray could only be arrayed satisfactorily in one plane. Its abrupt breaks in flare rate caused diffraction, reflection and distortion components. A 1996 JBL model 2344A Bi-Radial 'butt-cheeks' horn with a 100° x 100° output pattern from 1 kHz to 12.5 kHz By 1980, Keele was at JBL where he took both his and Altec's designs a step further. He mated a JBL-style diffraction horn to a secondary horn consisting of exponentially curved sides derived by using two radial formulas. This resulted in a hybrid constant directivity horn that was free from the distortion components associated with abrupt angle changes. The market responded well to the design in products such as the JBL model 4430 studio monitor with its 100° x 100° model 2344 Bi-Radial high frequency horn often called 'butt-cheeks'.

The Bi-Radial design had problems with apparent apex and arrayability in the same manner as the Mantaray. Twin Bessel Ramsa, the division of, introduced a twin Bessel constant directivity horn shortly after the Mantaray appeared. The design was very similar to the Mantaray and the Bi-Radial but it used a dual series Bessel expansion formula to determine the flare rate of the secondary horn section.

CD horn characteristics Most popular constant directivity horns (also known as CD horns) suffer from non-spherical wavefronts, limitations in arrayability, distortion at high levels as well as reflections and distortions related to the transition from diffraction slot to secondary horn. They tend toward a narrowing of dispersion pattern at the higher frequencies whose wavelengths approach the width of the throat or the width of the diffraction slot. Because the CD horn's high frequencies are more spread out over its coverage pattern, they appear attenuated relative to other horns. The CD horn requires an boost of approximately 6 dB per octave with a filter knee centered between 2 and 4 kHz (depending on horn design) in order to sound neutral and balanced.

Most manufacturers of active electronic responded to this requirement by adding an optional CD EQ boost filter or high frequency shelf filter. For instance, such circuitry was provided via internal jumper links by BSS in their FDS-310 crossover and by in their AC 22S and AC 23B crossovers. Rane allowed for greater front panel control of two bandpasses ('hi-mid' and 'high') using CD horn equalization including sweepable frequency range on their AC 24 crossover. Further refinements of the filtering process are available in -based crossovers. Multiple entry horn. A three-way multiple entry horn in which each passband enters the same horn In 1996, Ralph D.

Heinz of received a patent for a which incorporated multiple drivers for two bandpasses, high and mid, whose sound waves all exited into a single horn but at differing distances depending on the bandpass. It was marketed as the 'CoEntrant' horn. The mid- and high-frequency drivers in the Renkus-Heinz ST/STX product line both exited through a 'Complex Conic' waveguide. In the late 1990s, Thomas J. 'Tom' Danley of Sound Physics Labs (also known as 'Servodrive'), began working on a three-way multiple entry horn, bringing the SPL-td1 to market in 2000. The design used seven drivers, with one high frequency driver at the horn's throat, four mid-frequency drivers near the throat and two low frequency drivers ported closer to the horn mouth.

In 2001, Tom Danley began developing the 'Unity' horn for, patenting the improvement in 2002. Following the 2003 release of Yorkville's Unity line, Danley formed Danley Sound Labs and developed a significant improvement over the SPL-td1 called the 'Synergy' horn, yielding substantially better phase and magnitude response along with smoother polar pattern. The synergy horn design promises greater power output achieved from a smaller. Because the design retains pattern control through its crossover regions and over a large range of its total bandwidth, and because the acoustic center of the design is near the rear of the enclosure, it is more easily combined in arrays for public address applications. Waveguide/Horns The term 'waveguide' is used to describe horns with low acoustic loading, such as conic, quadratic, oblate spheroidal or elliptic cylindrical horns. These are designed more to control the radiation pattern rather than to gain efficiency via improved acoustic loading. All horns have some pattern control, and all waveguides provide a degree of acoustic loading, so the difference between a waveguide and a horn is a matter of judgement.

Quadratic-Throat Waveguide In 1999, of filed for a patent on a hybrid horn he called Quadratic-Throat Waveguide. The horn was basically a simple conic section but its throat was curved in a circular arc to match the desired throat size for proper mating to the speaker driver. Instead of increasing the horn mouth size with a flare to control midrange beaming, a relatively thin layer of foam covering the mouth edge was found to suit the same end. The QT waveguide, when compared to popular CD horns, produced about 3-4 dB lower levels of second harmonic distortion across all frequencies, and an average of 9 dB lower levels of the more annoying third harmonic distortion.

Being without a diffraction slot, the QT waveguide was free from problems with apparent apex, making it arrayable as needed for public address purposes. Oblate Spheroid WaveGuide Oblate spheroid waveguide (OSWG) horn designs attempt to improve directivity pattern control, provide a lower frequency of directivity (the lower the better to match woofers and mid-woofers' directivity), and--as claimed by the inventor--they mitigate higher order modes (HOM), a form of linear phase/amplitude-distortion. A major contribution to said comb-filter effects, namely the practically limited hornlength is explicitly not addressed by the theory of OSWG. Realized specimen attempt constant directivity and a smooth transition between the compression driver and the horn.

OSWG designs are applied to the higher frequency range, above about 1 kHz. Applications Public address and concert use.

The reentrant (reflex) horn loudspeaker or bullhorn, a type of folded horn speaker used widely in. To reduce the size of the horn, the sound follows a zigzag path through exponentially expanding concentric ducts in the central projection (b, c), emerging from the outer horn (d). Invented in the 1940s. Horn loudspeakers are used in many audio applications.

The drivers in horn loudspeakers can be very small, even for bass where conventional loudspeakers would need to be very large for equivalent performance. Horn loudspeakers can be designed to reproduce a wide range of frequencies using a single, small driver; to some extent these can be designed without requiring a. Lowther, Fostex, and Goodmans are firms which have produced such designs. Horn loudspeakers can also be used to provide the very high sound pressure levels needed for and public address applications, although in these high sound pressure applications, high is sometimes compromised for the sake of the necessary efficiency, and also for the controlled dispersion characteristics which are generally required in most large volume spaces. 'Gunness Focusing', a new method of counteracting some of the horn distortions, especially in the time domain, was pioneered by while he was with (EAW).

EAW horn-loaded loudspeakers that have been processed with this proprietary system show reduced compression driver diaphragm/ time-smear distortion while retaining high output power and controlled dispersion. Vointa De Femeie Serial Online Episodul 1 on this page. Concert venues often use large arrays of horn loudspeakers for high-volume bass reproduction ('bass bins' or ), in order to provide bass that concertgoers can not only hear but feel.

Combining multiple horn loudspeakers in an array affords the same benefits as having a single horn with a greater mouth area: the low frequency cut-off extends lower as the horn mouth gets larger, and the array has the greater output power of multiple drivers. Commercial theaters Commercial cinema theaters often use horn-loaded loudspeakers for pattern control and increased sensitivity needed to fill a large room. Some examples of manufacturers of commercial theater speakers are:, EAW,,, and.

Audiophiles and home use Consumer audio employs horn loudspeakers for controlled (to limit audio from room surfaces such as walls, floor, and ceiling) and for greater speaker. High end audio companies such as Avantgarde, and currently manufacture high priced horn loudspeakers for the home. Horn loudspeakers can provide very high efficiencies, making them a good match for very low-powered, such as amps or other amplifiers. After WWII, some early hi-fi fans went so far as to build low frequency horns whose mouths took up much of a wall of the listening room.

The throats were sometimes outside on the lawn, or in the basement. With the coming of stereo in the 1960s, this approach was rarely seen. Many loudspeaker buyers and do-it-yourself loudspeaker fans sought smaller designs for aesthetic reasons. Some use horn loudspeakers for audio reproduction, while others eschew horn systems for their harmonic resonances, finding in them an unpleasant form of. Since there are a variety of horn designs (of differing length, material, and taper, as well as different drivers) it is, to some extent, impossible to give such blanket characterizations to horn loudspeakers.Audiophiles using low power amplifiers, sometimes in the five to twenty-five watt range, may find the typically high efficiency of horn loudspeakers an especially attractive feature because it makes it possible to reach playable music levels.

Conversely, the high sensitivity can also make any background noise present at the amplifier outputs noticeably worse at the distances of a typical living room. Film soundtracks have great where peak levels are 20 dB greater than average levels.

The higher sensitivity aids in achieving sound levels at the listening position with typical ~100 watts-per-channel receiver/amplifiers used in. See also • • • Notes.