131-469: The LS3/5A (each element pronounced separately, without the stroke) is a small studio monitor loudspeaker originated by the BBC for use by outside broadcast vans to ensure quality of their broadcasts. The speaker concept set out transparent and natural sound as the goal, and the achievement of the result is widely acknowledged. The BBC granted licences to a small number of British firms, who first manufactured
262-475: A polymerisation process. About 80 years later it was realized that heating of styrol starts a chain reaction that produces macromolecules , following the thesis of German organic chemist Hermann Staudinger (1881–1965). This eventually led to the substance receiving its present name, polystyrene. The company I. G. Farben began manufacturing polystyrene in Ludwigshafen , about 1931, hoping it would be
393-508: A "V2" to the designation when the product was launched in 2005 in an act of transparency, even though the broadcaster has endorsed it. Falcon Acoustics was granted a licence by the BBC for the 15 ohm version of the LS3/5a in 2013 and commenced production in 2014 using drive units produced in-house by Falcon Acoustics. The Falcon F B110 bass unit is a re-engineered version using the same components of
524-462: A "blowing agent", a material that enables the beads to be expanded. Pentane is commonly used as the blowing agent. The beads are added to a continuously agitated reactor with the blowing agent, among other additives, and the blowing agent seeps into pores within each bead. The beads are then expanded using steam. EPS is used for food containers , molded sheets for building insulation , and packing material either as solid blocks formed to accommodate
655-456: A 305mm bass cone made with new thermoplastics led to development and deployment of the LS5/5 and LS5/6 monitors that occupied only 60% volume of its predecessor. As recording became less and less "live" and multi-tracking and overdubbing became the norm, the studio monitor became far more crucial to the recording process. When there was no original performance outside what existed on the tape,
786-500: A BBC white paper published in January 1963, the authors explored two-channel stereophony, and remarked that it was at a disadvantage compared with multi-channel stereophony that was already available in cinemas in that "the full intended effects is apparent only to observers located within a restricted area in front of the loudspeakers". The authors expressed reservations about dispersion and directionality in 2-channel systems, noting that
917-470: A Harbeth-made 5-inch woofer and a 0.75-inch tweeter". After a long history of repairing and servicing LS3/5a's from within both the professional and amateur arenas, Stirling Broadcast became involved in the manufacture of LS3/5a loudspeakers after purchasing and reselling the bankrupt Rogers stock as NOS. Once an LS3/5a License had been obtained from the BBC, Stirling Broadcast commissioned the manufacture of new T27 and B110 drive units from KEF and reintroduced
1048-458: A LS3/5A-sized cabinet and the same B110 driver from KEF. Linn acquired a hundred pairs of cabinets from the supplier of the bankrupt Chartwell, and used them for the very first Kans. The Kan, however, used a Scanspeak D2008 tweeter, subsequently followed by a re-badged OEM D20-LP-1 tweeter from Hiquphon in May 1984. Linn installed a very simple crossover into the box that transformed it into "one of
1179-563: A US patent for polystyrene foam as an insulation product in 1935 (USA patent number 2,023,204). PS foams also exhibit good damping properties, therefore it is used widely in packaging. The trademark Styrofoam by Dow Chemical Company is informally used (mainly US & Canada) for all foamed polystyrene products, although strictly it should only be used for "extruded closed-cell" polystyrene foams made by Dow Chemicals. Foams are also used for non-weight-bearing architectural structures (such as ornamental pillars ). Expanded polystyrene (EPS)
1310-466: A chain of polystyrene, giving a molar mass of 100,000–400,000 g/mol. Each carbon of the backbone has tetrahedral geometry , and those carbons that have a phenyl group (benzene ring) attached are stereogenic . If the backbone were to be laid as a flat elongated zig-zag chain, each phenyl group would be tilted forward or backward compared to the plane of the chain. The relative stereochemical relationship of consecutive phenyl groups determines
1441-440: A chequered corporate history. Audible differences could result from the mounting screws, grille fabric, or the origin of the wool. Rogers Audio was the earliest licensee, but went out of business before producing a single unit. The Rogers name was bought by Swisstone, who started manufacturing the 3/5A under licence in 1975. Rogers' production accounted for the majority, of around 43,000 pairs by 1988, and 50,000 pairs in total. Of
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#17327908438481572-468: A damping coating has been applied and given a synthetic rubber roll surround. The crossover has three settings of relative high frequency level, in steps of 0.5dB. Each crossover is tuned to the specific pairs of drive units. While Stirling's revision deviates technically from the specification, the company took steps to research and test to ensure the LS3/5A sound was preserved, "warts and all". Stirling added
1703-737: A few high-end studios, but with increasing costs of manufacture, they became rare. The once dominant JBL fell gradually into disfavour. One of the most striking trends was the growth of soft-dome monitors. These operated without horn-loaded drivers. Horns, while having advantages in transient response and efficiency, tend to be hard to listen to over long periods. The lack of distortion of high-end dome midrange & tweeters made them easy to work with all day (and night). Typical soft-dome systems were made by Roger Quested, ATC, Neil Grant and PMC and were actively driven by racks of active crossovers and amplifiers. Other monitor and studio designers like Tom Hidley, Phil Newall and Sam Toyoshima continued research into
1834-468: A grey/black color which distinguishes it from standard EPS. Several EPS producers have produced a variety of these increased thermal resistance EPS usage for this product in the UK and EU. Water vapor diffusion resistance ( μ ) of EPS is around 30–70. ICC-ES ( International Code Council Evaluation Service) requires EPS boards used in building construction meet ASTM C578 requirements. One of these requirements
1965-482: A linear phase response helps impulse response remain true to source without encountering "smearing". An unqualified reference to a monitor often refers to a near-field (compact or close-field) design. This is a speaker small enough to sit on a stand or desk in proximity to the listener, so that most of the sound that the listener hears is coming directly from the speaker, rather than reflecting off walls and ceilings (and thus picking up coloration and reverberation from
2096-672: A metallocene catalyst for the polymerisation reaction. Polystyrene is relatively chemically inert. While it is waterproof and resistant to breakdown by many acids and bases, it is easily attacked by many organic solvents (e.g. it dissolves quickly when exposed to acetone ), chlorinated solvents, and aromatic hydrocarbon solvents. Because of its resilience and inertness, it is used for fabricating many objects of commerce. Like other organic compounds, polystyrene burns to give carbon dioxide and water vapor , in addition to other thermal degradation by-products. Polystyrene, being an aromatic hydrocarbon , typically combusts incompletely as indicated by
2227-551: A modern LS3/5a in its truest form. The KEF B110 and KEF T27 have been faithfully recreated as the Falcon B110, and Falcon T27 using newly sourced original raw materials down to the smallest detail. Paired with Falcon's original transformer-style BBC specced crossovers, Falcon has created some of the truest LS3/5a speakers on today's market. In 1979, Linn Products created the Kan – a non-BBC specification bookshelf speaker that used
2358-559: A number of technical advantages. The interface between speaker and amplifier can be optimized, possibly offering greater control and precision, and advances in amplifier design have reduced the size and weight of the electronics significantly. The result has been that passive monitors have become far less common than powered monitors in project and home studios. In the 2000s, there was a trend to focus on "translation". Engineers tended to choose monitors less for their accuracy than for their ability to "translate" – to make recordings sound good on
2489-476: A request for a prototype in under a week because it resembled an experimental loudspeaker that the department had already developed for some preliminary acoustic scaling tests. The speaker had to be voiced by ear an octave at a time, because scale test results were inapplicable to a model of this size. Engineers took measurements; comparisons were performed against the LS5/8 – a large "Grade I monitor" already in use at
2620-553: A resonance of the bass drivers. Martin Colloms notes in Hi-Fi Critic that: "Hardly any component in either enclosure or driver may be substituted without the blend suffering audible disturbance. This is because the 3/5A sets such a high standard for tonal balance that errors which would pass unnoticed in an ordinary speaker are readily exposed". The BBC then licensed the product to a small number of private sector companies. In
2751-536: A review in Stereophile , John Atkinson remarked on how it was "virtually unknown for a speaker to be still available, virtually unchanged, 14 years after [its introduction]". J. Gordon Holt indicates in Stereophile that most of the cost lay inside the case, having been spent on a complex equaliser and phase-corrected crossover . However, Holt's colleague, John Atkinson, notes that the cabinet alone "costs
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#17327908438482882-566: A similar overall frequency response characteristic". In 1979, KEF released the Reference 101, a speaker that used the T27 (SP1032) with the B110B (SP1057) in a 6.7-litre cabinet "with a crossover of similar complexity to the LS3/5A". Martin Colloms said it possessed an almost perfectly flat frequency response, but that "it neither sounded as lifelike, nor did it really better the musical performance of
3013-722: A smoke-developed index of less than 450. ICC-ES requires the use of a 15-minute thermal barrier when EPS boards are used inside of a building. According to the EPS-IA ICF organization, the typical density of EPS used for insulated concrete forms ( expanded polystyrene concrete ) is 1.35 to 1.80 pounds per cubic foot (21.6 to 28.8 kg/m ). This is either Type II or Type IX EPS according to ASTM C578. EPS blocks or boards used in building construction are commonly cut using hot wires. Extruded polystyrene foam (XPS) consists of closed cells. It offers improved surface roughness, higher stiffness and reduced thermal conductivity. The density range
3144-566: A split via a channel system of gates and runners. EPS is colloquially called "styrofoam" in the Anglosphere , an genericization of Dow Chemical's brand of extruded polystyrene . Sheets of EPS are commonly packaged as rigid panels (common in Europe is a size of 100 cm x 50 cm, usually depending on an intended type of connection and glue techniques, it is, in fact, 99.5 cm x 49.5 cm or 98 cm x 48 cm; less common
3275-496: A sprayed-on coating is necessary to prevent saturation. Oriented polystyrene (OPS) is produced by stretching extruded PS film, improving visibility through the material by reducing haziness and increasing stiffness. This is often used in packaging where the manufacturer would like the consumer to see the enclosed product. Some benefits to OPS are that it is less expensive to produce than other clear plastics such as polypropylene (PP), (PET), and high-impact polystyrene (HIPS), and it
3406-513: A suitable replacement for die-cast zinc in many applications. Success was achieved when they developed a reactor vessel that extruded polystyrene through a heated tube and cutter, producing polystyrene in pellet form. Ray McIntire (1918–1996), a chemical engineer of Dow Chemical, rediscovered a process first patented in early 1930s by Swedish inventor Carl Munters . According to the Science History Institute, "Dow bought
3537-470: A twelve-inch mid-bass driver. Most studios, however, also used more modest monitoring devices to check how recordings would sound through car speakers and cheap home systems. A favourite "grot-box" monitor employed in this way was the Auratone 5C, a crude single-driver device that gave a reasonable facsimile of typical lo-fi sound. However, a backlash against the behemoth monitor was soon to take place. With
3668-431: A variety of playback systems, from stock car radios and standard boom boxes to esoteric audiophile systems. As the mix engineer Chris Lord-Alge has noted: But it is uncertain just what tools aid translation. Some producers argue that accuracy is still the best guarantee. If a producer or audio engineer is listening to recorded tracks and mixing tracks using a "flattering" monitor speaker, they may miss subtle problems in
3799-497: Is 120 x 60 cm; size 4 by 8 ft (1.2 by 2.4 m) or 2 by 8 ft (0.61 by 2.44 m) in the United States). Common thicknesses are from 10 mm to 500 mm. Many customizations, additives, and thin additional external layers on one or both sides are often added to help with various properties. An example of this is lamination with cement board to form a structural insulated panel . Thermal conductivity
3930-427: Is a 110 mm speaker with a doped Bextrene (a proprietary type of polystyrene copolymer) cone and a neoprene surround. The KEF T27 SP1032 has a 19 mm mylar dome fitted and is with a perforated protection grille. The loudspeaker has an internal volume of approximately 5 litres. The speaker cabinet ( loudspeaker enclosure ) measuring 31 by 19 by 16 centimetres (12.2 in × 7.5 in × 6.3 in),
4061-430: Is a compact studio monitor designed for listening at close distances (3 to 5 feet (0.9 to 1.5 m)), so, in theory, the effects of poor room acoustics are greatly reduced.) The 4310 was small enough to be placed on the recording console and listened to from much closer distances than the traditional large wall-(or "soffit") mounted main monitors. As a result, studio-acoustic problems were minimized. Smaller studios found
LS3/5A - Misplaced Pages Continue
4192-481: Is a distinct compound). By 1845 Jamaican-born chemist John Buddle Blyth and German chemist August Wilhelm von Hofmann showed that the same transformation of styrol took place in the absence of oxygen. They called the product "meta styrol"; analysis showed that it was chemically identical to Simon's Styroloxyd. In 1866 Marcellin Berthelot correctly identified the formation of meta styrol/Styroloxyd from styrol as
4323-524: Is a rigid and tough, closed-cell foam with a normal density range of 11 to 32 kg/m . It is usually white and made of pre-expanded polystyrene beads. The manufacturing process for EPS conventionally begins with the creation of small polystyrene beads. Styrene monomers (and potentially other additives) are suspended in water, where they undergo free-radical addition polymerization. The polystyrene beads formed by this mechanism may have an average diameter of around 200 μm. The beads are then permeated with
4454-449: Is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene . Polystyrene can be solid or foamed . General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to air and water vapor and has a relatively low melting point. Polystyrene is one of the most widely used plastics , with the scale of its production being several million tonnes per year. Polystyrene
4585-450: Is about 28–34 kg/m . Extruded polystyrene material is also used in crafts and model building, in particular architectural models. Because of the extrusion manufacturing process, XPS does not require facers to maintain its thermal or physical property performance. Thus, it makes a more uniform substitute for corrugated cardboard . Thermal conductivity varies between 0.029 and 0.039 W/(m·K) depending on bearing strength/density and
4716-437: Is commonly injection molded , vacuum formed , or extruded, while expanded polystyrene is either extruded or molded in a special process. Polystyrene copolymers are also produced; these contain one or more other monomers in addition to styrene. In recent years the expanded polystyrene composites with cellulose and starch have also been produced. Polystyrene is used in some polymer-bonded explosives (PBX). Polystyrene (PS)
4847-569: Is crucial. Among audio engineers , the term monitor implies that the speaker is designed to produce relatively flat (linear) phase and frequency responses . In other words, it exhibits minimal emphasis or de-emphasis of particular frequencies, the loudspeaker gives an accurate reproduction of the tonal qualities of the source audio ("uncolored" and "transparent" are synonyms), and there will be no relative phase shift of particular frequencies—meaning no distortion in sound-stage perspective for stereo recordings. Beyond stereo sound-stage requirements,
4978-478: Is derived from BBC naming convention: the "LS3" designation meant it was a loudspeaker intended for outside broadcasting , as opposed to the "LS5" loudspeaker, intended for studio monitoring. The number after the stroke is the model number, the LS3/5 is "number 5" outside-broadcasting loudspeaker. The letter that follows denotes alterations to the original specification, of which there was only one in this instance after
5109-489: Is exploited for extrusion (as in Styrofoam ) and also for molding and vacuum forming , since it can be cast into molds with fine detail. The temperatures behavior can be controlled by photocrosslinking. Under ASTM standards, polystyrene is regarded as not biodegradable . It is accumulating as a form of litter in the outside environment , particularly along shores and waterways, especially in its foam form, and in
5240-468: Is generally considered to be non-biodegradable. However, certain organisms are able to degrade it, albeit very slowly. In 2015, researchers discovered that mealworms , the larvae form of the darkling beetle Tenebrio molitor , could digest and subsist healthily on a diet of EPS. About 100 mealworms could consume between 34 and 39 milligrams of this white foam in a day. The droppings of mealworm were found to be safe for use as soil for crops. In 2016, it
5371-555: Is ideally suited to the reproduction of program having a limited dynamic-range requirement, for example chamber music; he said that the LS3/5A "has never boogied and never will; it's just too polite ever to cut the mustard on rock, or even straightahead jazz ". A total of 11 companies were ever granted licences by the BBC to manufacture the model, a maximum of 3 at any given time. The product proved highly challenging to manufacture, if for no other reason than tight specifications and consistency of parts, and many of these companies would have
LS3/5A - Misplaced Pages Continue
5502-410: Is initiated with free radicals . Ziegler–Natta polymerization can produce an ordered syndiotactic polystyrene with the phenyl groups positioned on alternating sides of the hydrocarbon backbone. This form is highly crystalline with a T m (melting point) of 270 °C (518 °F). Syndiotactic polystyrene resin is currently produced under the trade name XAREC by Idemitsu corporation, who use
5633-468: Is made using 12 mm (0.47 in) birch plywood strengthened at every joint with beech braces, and heavily damped . Although there was no specification for the wood of the original LS3/5 cabinets, the BBC closely specified wood types in defining the LS3/5A due to concerns that other hard woods – specifically Parana pine , with which the BBC conducted tests – would cause noticeable colouration (i.e. detract from sonic neutrality) due to interaction with
5764-560: Is measured according to EN 12667. Typical values range from 0.032 to 0.038 W/(m⋅K) depending on the density of the EPS board. The value of 0.038 W/(m⋅K) was obtained at 15 kg/m while the value of 0.032 W/(m⋅K) was obtained at 40 kg/m according to the datasheet of K-710 from StyroChem Finland. Adding fillers (graphites, aluminum, or carbons) has recently allowed the thermal conductivity of EPS to reach around 0.030–0.034 W/(m⋅K) (as low as 0.029 W/(m⋅K)) and as such has
5895-548: Is naturally transparent , but can be colored with colorants. Uses include protective packaging (such as packing peanuts and optical disc jewel cases ), containers, lids, bottles, trays, tumblers, disposable cutlery , in the making of models, and as an alternative material for phonograph records . As a thermoplastic polymer, polystyrene is in a solid (glassy) state at room temperature but flows if heated above about 100 °C, its glass transition temperature . It becomes rigid again when cooled. This temperature behaviour
6026-412: Is not produced commercially. [REDACTED] The only commercially important form of polystyrene is atactic , in which the phenyl groups are randomly distributed on both sides of the polymer chain. This random positioning prevents the chains from aligning with sufficient regularity to achieve any crystallinity . The plastic has a glass transition temperature T g of ~90 °C. Polymerization
6157-732: Is often done to introduce polar groups. Much of modern biomedical research relies on the use of such products; they, therefore, play a critical role in pharmaceutical research. Thin sheets of polystyrene are used in polystyrene film capacitors as it forms a very stable dielectric , but has largely fallen out of use in favor of polyester . Polystyrene foams are 95–98% air. Polystyrene foams are good thermal insulators and are therefore often used as building insulation materials, such as in insulating concrete forms and structural insulated panel building systems. Grey polystyrene foam, incorporating graphite , has superior insulation properties. Carl Munters and John Gudbrand Tandberg of Sweden received
6288-404: Is that the limiting oxygen index of EPS as measured by ASTM D2863 be greater than 24 volume %. Typical EPS has an oxygen index of around 18 volume %; thus, a flame retardant is added to styrene or polystyrene during the formation of EPS. The boards containing a flame retardant when tested in a tunnel using test method UL 723 or ASTM E84 will have a flame spread index of less than 25 and
6419-523: Is the Classic 3/5. Preceding the 3/5A, KEF's Cresta (1967), KEFKIT4 (1969), Cresta II (1970), Coda (1971) were all 2-way loudspeakers that used the B110/T27 combination. KEF released its CS1A constructor kit (1981) to tap the home-build market. According to the product brochure, the kit includes "the same KEF drive units originally specified for the LS3/5A with a somewhat simplified dividing network giving
6550-723: Is used for producing disposable plastic cutlery and dinnerware , CD "jewel" cases , smoke detector housings, license plate frames, plastic model assembly kits, and many other objects where a rigid, economical plastic is desired. Production methods include thermoforming ( vacuum forming ) and injection molding . Polystyrene Petri dishes and other laboratory containers such as test tubes and microplates play an important role in biomedical research and science. For these uses, articles are almost always made by injection molding, and often sterilized post-molding, either by irradiation or by treatment with ethylene oxide . Post-mold surface modification, usually with oxygen -rich plasmas ,
6681-401: The sooty flame. The process of depolymerizing polystyrene into its monomer , styrene , is called pyrolysis . This involves using high heat and pressure to break down the chemical bonds between each styrene compound. Pyrolysis usually goes up to 430 °C. The high energy cost of doing this has made commercial recycling of polystyrene back into styrene monomer difficult. Polystyrene
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#17327908438486812-428: The tacticity , which affects various physical properties of the material. In polystyrene, tacticity describes the extent to which the phenyl group is uniformly aligned (arranged at one side) in the polymer chain. Tacticity has a strong effect on the properties of the plastic. Standard polystyrene is atactic. The diastereomer where all of the phenyl groups are on the same side is called isotactic polystyrene, which
6943-438: The "face-to-face listening arrangement" was not able to give an acceptable presentation for a centrally-located observer in a domestic setting. The paper concluded: The achievement of suitable directional characteristics within the aesthetic and economic limitations applying to domestic equipment will however require a much greater research effort than either the corporation or the radio industry have so far been able to devote to
7074-667: The 100,000 pairs ballpark. Professional audio companies such as Genelec , Neumann (formerly Klein + Hummel), Quested , and M & K sell almost exclusively to recording studios and record producers , who comprise key players in the professional monitor market. Most of the consumer audio manufacturers confine themselves to supplying speakers for home hi-fi systems. Companies that straddle both worlds, like Amphion Loudspeakers , ADAM , Dynaudio , Focal/JM Labs , JBL, PMC , surrounTec and Tannoy tend to clearly differentiate their monitor and hi-fi lines. Bextrene Polystyrene ( PS ) / ˌ p ɒ l i ˈ s t aɪ r iː n /
7205-922: The 15 ohm LS3/5a is held by Falcon Acoustics Despite not being a "commercial product" at the outset, the LS3/5A was commercially successful in its twenty-something-year life, from 1975 until approximately 2000, when the availability of KEF drive units came to an end. The speaker has amassed an "enthusiastic, focused, and loyal [...] following, and none so large or vocal", according to Paul Seydor in The Absolute Sound . Estimates of their sales differ, possibly due to scope and cut-off: when it ceased production in 1998, "some 100,000 pairs were in circulation, with 3000 pairs sold in its last year alone", according to Seydor; in 2001, Ken Kessler similarly estimated in Hi-fi News that 100,000 pairs had been produced. In 2007, Martin Colloms reported "more than 60,000 pairs of
7336-561: The 1980s. While its sound-quality has often been derided, even by those who monitor through it, the NS-10 continues in use to this day and many more successful recordings have been produced with its aid over the past twenty five years than with any other monitor. By the mid-1980s the near-field monitor had become a permanent fixture. The larger studios still had large soffit-mounted main monitors but producers and engineers spent most of their time working with near-fields. Common large monitors of
7467-458: The 4310 ideal and that monitor and its successor, the 4311, became studio fixtures throughout the 1970s. Ironically, the 4310 had been designed to replicate the sonic idiosyncrasies of the Altec 604 but in a smaller package to cater for the technical needs of the time. The 4311 was so popular with professionals that JBL introduced a domestic version for the burgeoning home-audio market. This speaker,
7598-431: The Altec 604 but was a more accurate and powerful speaker and it quickly made inroads against the industry standard. However, it was the more compact 4310 that revolutionized monitoring by introducing the idea of close or "nearfield" monitoring. (The sound field very close to a sound source is called the "near-field." By "very close" is meant in the predominantly direct, rather than reflected, sound field. A near-field speaker
7729-419: The BBC authorised licensees to manufacture models capable of being bi-wired , but stipulated that the performance in single-wired mode must meet the original specification. KEF started making the bi-wire crossover, designated SP2195, available in 1991. Upon obtaining a BBC licence to produce legacy 11-ohm LS3/5A, Stirling Broadcast commissioned KEF to produce new T27 and B110 drive units. Stirling had to rethink
7860-413: The BBC broadcasting unit was about to order another batch of the monitor, it was found that the supplier had modified the drive units, meaning the LS3/5 design had to be fundamentally revised. The BBC's Designs Department was called upon to adapt the product in light of the supply changes. Modifications were made to adapt to the new drive units and deal with the altered resonance pattern, and the LS3/5 became
7991-576: The BBC required monitors to sound balanced, be neutral in tone, and lack colouration. Monitor usage in the industry was highly conservative, with almost monopolistic reliance on industry "standards", in spite of the sonic failings of these aging designs. The Altec 604 had a notoriously ragged frequency response but almost all U.S. studios continued to use it because virtually every producer and engineer knew its sound intimately and were practiced at listening through its sonic limitations. Recording through unfamiliar monitors, no matter how technically advanced,
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#17327908438488122-511: The BBC specification. Crossovers are close tolerance pair matched versions of the original BBC LS3/5a crossover design [4] using tapped transformers for high frequency adjustments. [25] Falcon also manufacture the Q7 which, whilst using the same Falcon B110 and T27 drive units as used in the Falcon LS3/5a, has a slightly modified LS3/5a "style" enclosure. The height (309mm) and width (190mm) of
8253-537: The JBL L-100, (or "Century") was a massive success and became the biggest-selling hi-fi speaker ever within a few years. By 1975, JBL overtook Altec as the monitor of choice for most studios. The major studios continued to use huge designs mounted on the wall which were able to produce prodigious SPL's and amounts of bass. This trend reached its zenith with The Who 's use of a dozen JBL 4350 monitors, each capable of 125 dB and containing two fifteen-inch woofers and
8384-681: The L-100, was used in a large number of homes, while the Yamaha NS-10 served both domestically and professionally during the 1980s. Despite not being a "commercial product" at the outset, the BBC licensed production of the LS3/5A monitor, which it used internally. It was commercially successful in its twenty-something-year life, from 1975 until approximately 1998. The diminutive BBC speaker has amassed an "enthusiastic, focused, and ... loyal following", according to Paul Seydor in The Absolute Sound . Estimates of their sales differ, but are generally in
8515-540: The LS3/5, thus the "A". For its outside broadcasting monitoring, the BBC required a small studio monitor suitable for near-field monitoring of the frequency range from 400 Hz to about 20 kHz. The principal constraints were space and situations where using headphones is unsatisfactory, such as in mobile broadcasting vans. There were no commercial constraints. The BBC Research Department, then situated at Kingswood Warren, were responsible for development work, and commenced scaling tests in 1968. They were able to answer
8646-417: The LS3/5A from various licensees sold in significant numbers in its life of over a quarter of a century. Sales estimates range from 60,000 to 100,000 pairs. In the tail end of the 1990s, due to the parts being discontinued, the 3/5 had technically reached the end of the road. Some licensees continued to make small numbers of speakers, for a while, using re-manufactured parts. However, Stirling Broadcast, one of
8777-423: The LS3/5A. The BBC then licensed the product to a small number of private sector companies. Production began in 1975. In 1987, as a result of reassessment of the product due to consistency issues in the manufacture of the mid–bass driver, the drivers were modified and the crossover changed. The overall impedance of the crossover fell to 11 ohms from the original 15 ohms. The various official versions of
8908-454: The LS3/5A. This company, founded in Sussex in the 1960s by Spencer Hughes (a BBC electroacoustic engineer) and his wife Dorothy (hence the brandname) and later owned by Philip Swift, is known for building high-end loudspeakers. Spendor built the LS3/5A and started with a S3/5, which was developed by Spencer's son Derek, in 1998. This type was two times modified, since 2019 the current type
9039-523: The LS3/5a to the market. After KEF stopped manufacturing the LS3/5a speaker units, the LS3/5a could no longer be reproduced in its original form. In 2018 Maarten van Druten (moviemaker an audiophile from the Netherlands) designed together with LS3/5a Yahoo group member Bert a L3/5a DIY kit based on the Rogers LS3/5a version but with enhanced, more modern parts. Leon Huijgen (Liiondias) designed
9170-479: The LS5/8 – a large "Grade I monitor" already in use at the time – and with live sources, the BBC Research Department developed the LS3/5, which became the famous LS3/5A that was used from 1975 to much of the 1990s and beyond by the BBC and audiophiles alike. In the late 1960s JBL introduced two monitors which helped secure them pre-eminence in the industry. The 4320 was a direct competitor to
9301-602: The Pacific Ocean. Polystyrene was discovered in 1839 by Eduard Simon , an apothecary from Berlin. From storax , the resin of the Oriental sweetgum tree Liquidambar orientalis , he distilled an oily substance, that he named styrol, now called styrene . Several days later, Simon found that it had thickened into a jelly, now known to have been a polymer , that he dubbed styrol oxide ("Styroloxyd") because he presumed that it had resulted from oxidation ( styrene oxide
9432-1048: The United States, a position it maintained in its various incarnations (the 604 went through eleven model-changes) over the next 25 years. It was common in US studios throughout the 1950s and 60s and remained in continuous production until 1998. In the UK, Tannoy introduced its own coaxial design, the Dual Concentric, and this assumed the same reference role in Europe as the Altec 604 held in the US. The British Broadcasting Corporation researchers conducted evaluations on as many speakers as they could obtain in around 1948, but found commercial loudspeaker makers had little to offer that met their requirements. The BBC needed speakers that worked well with program material within real professional and domestic settings environments, and not just fulfil technical measurements such as frequency-response, distortion, monitors in anechoic chambers. Above all,
9563-467: The advent of punk , new wave , indie , and lo-fi , a reaction to high-tech recording and large corporate-style studios set in and do-it-yourself recording methods became the vogue. Smaller, less expensive, recording studios needed smaller, less expensive monitors and the Yamaha NS-10 , a design introduced in 1978 ironically for the home audio market, became the monitor of choice for many studios in
9694-416: The average value is ~0.035 W/(m·K). Water vapor diffusion resistance (μ) of XPS is around 80–250. Commonly extruded polystyrene foam materials include: Although it is a closed-cell foam, both expanded and extruded polystyrene are not entirely waterproof or vapor proof. In expanded polystyrene there are interstitial gaps between the expanded closed-cell pellets that form an open network of channels between
9825-694: The bonded pellets, and this network of gaps can become filled with liquid water. If the water freezes into ice, it expands and can cause polystyrene pellets to break off from the foam. Extruded polystyrene is also permeable by water molecules and can not be considered a vapor barrier. Water-logging commonly occurs over a long period in polystyrene foams that are constantly exposed to high humidity or are continuously immersed in water, such as in hot tub covers, in floating docks, as supplemental flotation under boat seats, and for below-grade exterior building insulation constantly exposed to groundwater. Typically an exterior vapor barrier such as impermeable plastic sheeting or
9956-559: The broadcasting unit was about to order another batch of the monitor, it was found that KEF had discontinued the B110 (A6362) and the T27 (A6340) in favour of the B110 (SP1003) and T27 (SP1032) specification, and was already using them in the Coda, one of their own-brand commercial loudspeakers. Thus the design had to be revised because these new units had different impedances, technical characteristics and altered resonance patterns.[2][4] The tweeter
10087-499: The cabinet has the same dimensions as the LS3/5s but has an "extended" depth (230mm). This results in an optimal Q=0.7 and provides the speaker with extended bass response (60Hz-20kHz +/- 3dB). Founded in 2014, Falcon Acoustics is a joint effort between Malcolm Jones and Jerry Bloomfield. Jones, a member of the original LS3/5a design team and designer of the very drivers found in the first LS3/5a speakers, set out with Bloomfield to create
10218-501: The changes, saw its overall impedance fall to 11 ohms from the original 15 ohms. KEF also manufactured and supplied the crossover with the drive units in kits where the pairs have been electrically matched by computer to ensure balanced performance. Martin Colloms had implied in Hi-fi News in August 1988 that the BBC had taken a pragmatic decision to revise the design, to ensure that targeted production levels could be maintained. In 1990,
10349-418: The characteristics of every type of system available; technical faults must not be apparent to even a minority of listeners while remaining undetected by the operating staff. It is further argued that, because of technical progress in the science of sound transmission, equipment in the studio originating the programme should have a higher standard of performance than the equipment employed in reproducing it, since
10480-407: The design principle or cost, has a completely flat frequency response; all speakers color the sound to some degree. Monitor speakers are assumed to be as free as possible from coloration . While no rigid distinction exists between consumer speakers and studio monitors, manufacturers usually accent the difference in their marketing material. Generally, studio monitors are physically robust, to cope with
10611-409: The earlier versions. The accuracy and stability of its stereo imaging and its clean midrange reproduction are also appreciated qualities. J. Gordon Holt suggests that the quality was "comparable to that from Quad Electrostatics , at far lower cost and with added bonuses of slightly smoother high end, better stereo imaging, a broader listening area". John Atkinson suggests in Stereophile that the LS3/5A
10742-455: The early years of the recording industry in the 1920s and 1930s, studio monitors were used primarily to check for noise interference and obvious technical problems rather than for making artistic evaluations of the performance and recording. Musicians were recorded live and the producer judged the performance on this basis, relying on simple tried-and-true microphone techniques to ensure that it had been adequately captured; playback through monitors
10873-414: The external High End crossover The result is non-compromise pro audio LS3/5a that everyone is allowed to build. Studio monitor Studio monitors are loudspeakers in speaker enclosures specifically designed for professional audio production applications, such as recording studios , filmmaking , television studios , radio studios and project or home studios, where accurate audio reproduction
11004-453: The fastest and most involving wall mount miniatures ever", according to Martin Colloms. Jim Rogers, who set up J R Loudspeakers Ltd after the collapse of Rogers Audio, released the JR149 in 1977 using the same drive units as the LS3/5A in a cylindrical aluminium cabinet. A review of the JR149 in the May 1977 Hi-Fi News and Record Review found that the "general quality was very comparable" to
11135-582: The former has a longer life. In fact, most professional audio production studios have several sets of monitors spanning the range of playback systems in the market. This may include a sampling of large, expensive speakers as may be used in movie theatres, hi-fi style speakers, car speakers, portable music systems, PC speakers and consumer-grade headphones. Amplification: Studio monitors may be " active " (including one or more internal power amplifier(s)), or passive (requiring an external power amplifier ). Active models are usually bi-amplified , which means that
11266-430: The gut of superworms that contain encoded enzymes associated with the degradation of polystyrene and the breakdown product styrene. The bacterium Pseudomonas putida is capable of converting styrene oil into the biodegradable plastic PHA . This may someday be of use in the effective disposing of polystyrene foam. It is worthy to note the polystyrene must undergo pyrolysis to turn into styrene oil. Polystyrene
11397-415: The high volumes and physical knocks that may happen in the studio, and are used for listening at shorter distances (e.g., near field) than hi-fi speakers, though nothing precludes them from being used in a home-sized environment. In one prominent recording magazine, Sound on Sound , the number of self-amplified (active) studio monitor reviews significantly outweighs the number of passive monitor reviews over
11528-448: The high volumes and sudden sound bursts that may happen in the studio when playing back unmastered mixes. Broadcasting and recording organisations employ audio engineers who use loudspeakers to assess the aesthetic merits of the programme and to tailor the balance by audio mixing and mastering to achieve the desired result. Loudspeakers are also required at various points in the audio processing chain to enable engineers to ensure that
11659-534: The input sound signal is divided into two parts by an active crossover for low and high frequency components. Both parts are amplified using separate low- and high-frequency amplifiers, and then the low-frequency part is routed to a woofer and the high-frequency part is routed to a tweeter or horn . Bi-amplification is done so that a cleaner overall sound reproduction can be obtained, since signals are easier to process before power amplification. Consumer loudspeakers may or may not have these various design goals. In
11790-471: The item being protected or as loose-fill "peanuts" cushioning fragile items inside boxes. EPS also has been widely used in automotive and road safety applications such as motorcycle helmets and road barriers on automobile race tracks . A significant portion of all EPS products are manufactured through injection molding. Mold tools tend to be manufactured from steels (which can be hardened and plated), and aluminum alloys. The molds are controlled through
11921-460: The last batch of licensees, completely redesigned the product based on the audio signature of the original, and launched the LS3/5A v2 with the full endorsement of the broadcaster in early 2006. In 2014, production of the 15 ohm version of the LS3/5a with a full BBC Licence was re-commenced by Falcon Acoustics [25] using re-engineered versions of the original drive units and the original design BBC crossover [4] all produced in-house. The product name
12052-690: The manufacturer the same as the retail price of a typical massmarket [ sic ] speaker". Only specific speaker drivers manufactured to strict tolerances may be used. There were other measures to control diffraction and ensure tonal neutrality. The circuitry provides equalisation in both high and low frequency sections. The 13-element crossover includes an inductor for the treble section with seven positions that allows adjustment to match level of mid to treble sensitivities. The design also specifies high quality screened air-gap inductors and film capacitors. David Prakel in Hi-Fi Answers suggests it
12183-414: The mic'ing or recording quality that a more precise monitor would expose. Other producers feel that monitors should mimic home audio and car speakers, as this is what most consumers listen to music on. Still more believe that monitors need to be relentlessly unflattering, so that the producer and engineer must work hard to make recordings sound good. No speaker, monitor or hi-fi sound system, regardless of
12314-445: The mistake of replacing the 604 with the 605A Duplex, a design widely regarded as inferior to its predecessor. There was a backlash from some record companies and studios and this allowed Altec's competitor, JBL (a company originally started by 604 designer James B. Lansing), to make inroads into the pro monitor market. Capitol Records replaced their Altecs with JBL D50 Monitors and a few years later their UK affiliate, EMI , also made
12445-467: The molecules consist of thousands of atoms, the cumulative attractive force between the molecules is large. When heated (or deformed at a rapid rate, due to a combination of viscoelastic and thermal insulation properties), the chains can take on a higher degree of confirmation and slide past each other. This intermolecular weakness (versus the high intramolecular strength due to the hydrocarbon backbone) confers flexibility and elasticity. The ability of
12576-465: The monitor became the touchstone of all engineering and production decisions. As a result, accuracy and transparency became paramount and the conservatism evident in the retention of the 604 as the standard for over twenty years began to give way to fresh technological development. Despite this, the 604 continued to be widely used - mainly because many engineers and producers were so familiar with their sonic signature that they were reluctant to change. In
12707-601: The move to JBL's. Although Altec re-introduced the 604 as the "E" version Super Duplex in response to the criticism, they now had a major industry rival to contend with. Over the next decade most of the developments in studio monitor design originated from JBL. As the public broadcaster in the UK, the BBC had the determinant role in defining industry standards. Its renowned research departments invested considerable resources in determining studio monitor suited to their different broadcasting needs, and also created their own models from first principles. A 1958 research paper identified
12838-446: The normal condition and avoidable departures from this state, while justified upon occasion, should not be allowed to become a permanent feature of the system. In designing a loudspeaker, the BBC established the compromise that had to be established between size, weight and cost considerations. Two-way designs were preferred due to the inherently simpler crossover network, but were subject to the limitations of speaker driver technology at
12969-504: The original KEF B110 SP1003 with a doped Bextrene cone and a neoprene surround. The Falcon F T27 tweeter again uses the same components as the original KEF T27 SP1032 and has a 19 mm mylar dome fitted. Both Falcon units were designed by Malcolm Jones, who, while employed at KEF between 1962 and 1974, was responsible for the design of the KEF B110 and T27 units originally used in the LS3/5 and LS3/5a. Both units are graded/selected to meet
13100-414: The original LS3/5As were made". John Atkinson noted that it had sold in excess of 60,000 up to 1988, of which Rogers represented two-thirds. Atkinson notes in 2007 that the sound of the speaker had not dated whilst many other speakers of the 1960s and 70s had. He guessed that LS3/5A remained competitive due to the exhaustive considerations and top engineering talent that went into its design; maybe some luck
13231-590: The other main manufacturers, Spendor produced about 11,000 pairs, and Audiomaster 10,000. Dudley Harwood, the BBC engineer instrumental in the creation of the 3/5A, started Harbeth and obtained a licence in 1977, but the company produced no LS3/5As for a decade. Eventually, Harbeth accounted for 7,000 pairs. KEF, who obtained its licence in 1993 (and at which point there were 4 concurrent manufacturer licensees), claims approximately 4,000 pairs were made from 1994 to 1998. Other licensees included Chartwell, RAM, Goodmans, Graham Audio and Stirling Broadcast.A current licence for
13362-457: The past two decades indicating that studio monitors are predominantly self-amplified, although not exclusively so. Hi-fi speakers usually require external amplification. Monitors are used by almost all professional producers and audio engineers. The claimed advantage of studio monitors is that the production translates better to other sound systems. In the 1970s, the JBL 4311's domestic equivalent,
13493-434: The polymerization, the carbon-carbon π bond of the vinyl group is broken and a new carbon-carbon σ bond is formed, attaching to the carbon of another styrene monomer to the chain. Since only one kind of monomer is used in its preparation, it is a homopolymer. The newly formed σ bond is stronger than the π bond that was broken, thus it is difficult to depolymerize polystyrene. About a few thousand monomers typically comprise
13624-526: The problems of cinema sound. Stereophonic sound was in its infancy, having been pioneered in Britain by an engineer who worked for EMI . Designing monitors for recording studios was not a major priority. The first high-quality loudspeaker developed expressly as a studio monitor was the Altec Lansing Duplex 604 in 1944. This innovative driver has historically been regarded as growing out of
13755-434: The product in 1975. The product underwent a change in 1987 due to consistency issues in manufacturing, and again in around 2003 when original parts from KEF ran out. Upwards of 60,000 pairs of the speaker have been sold. Reviewers have recognised its enormous importance as a bookshelf design. The LS3/5A is a commercially produced loudspeaker driven by the need of the BBC to monitor and assess broadcast programme quality. It
13886-431: The product when KEF finally ceased manufacturing the drive units in about 2000. Working with drivers from SEAS and Scanspeak, Derek Hughes developed for Stirling a new crossover that enabled the new proprietary drivers to mimic the response of the original KEF drivers they replaced. Specifically, the T27 was replaced by a 19 mm doped fabric dome tweeter. The mid–bass unit is a formed polypropylene co-polymer cone to which
14017-634: The programme is reasonably free from technical defects, such as audible distortion or background noise. The engineer may mix programming that will sound pleasing on the widest range of playback systems used by regular listeners (i.e. high-end audio , low-quality radios in clock radios and " boom boxes ", in club PA systems , in a car stereo or a home stereo). While some broadcasters like the BBC generally believe in using monitors of "the highest practicable standard of performance", some audio engineers argue that monitoring should be carried out with loudspeakers of mediocre technical quality to be representative of
14148-676: The raw material for molding parts or extruding sheets. BASF and Stastny applied for a patent that was issued in 1949. The molding process was demonstrated at the Kunststoff Messe 1952 in Düsseldorf. Products were named Styropor. The crystal structure of isotactic polystyrene was reported by Giulio Natta . In 1954, the Koppers Company in Pittsburgh , Pennsylvania, developed expanded polystyrene (EPS) foam under
14279-467: The regular systems end-users are likely to be listening with; or that some technical defects are apparent only with high-grade reproducing equipment and therefore can be ignored. However, as a public broadcaster dealing with a lot of live material, the BBC holds the view that studio monitors should be "as free as possible from avoidable defects". It is argued that real life low-grade sound systems are so different that it would be impossible to compensate for
14410-423: The rights to Munters's method and began producing a lightweight, water-resistant, and buoyant material that seemed perfectly suited for building docks and watercraft and for insulating homes, offices, and chicken sheds." In 1944, Styrofoam was patented. Before 1949, chemical engineer Fritz Stastny (1908–1985) developed pre-expanded PS beads by incorporating aliphatic hydrocarbons, such as pentane. These beads are
14541-413: The room). Monitor speakers may include more than one type of driver (e.g., a tweeter and a woofer ) or, for monitoring low-frequency sounds, such as bass drum , additional subwoofer cabinets may be used. There are studio monitors designed for mid-field or far-field use as well. These are larger monitors with approximately 12 inch or larger woofers, suited to the bigger studio environment. They extend
14672-485: The sound goal, in a monaural system: It is assumed that the ideal to be aimed at in the design of a sound reproducing system is realism, i.e. that the listener should be able to imagine himself to be in the presence of the original source of sound. There is, of course, scope for legitimate experiment in the processing of the reproduced signals in an endeavour to improve on nature, however, realism, or as near an approach to it as may be possible, ought surely to be regarded as
14803-544: The speaker/room interface and led developments in room design, trapping, absorption and diffusion to create a consistent and neutral monitoring environment. The main post-NS-10 trend has been the almost universal acceptance of powered monitors where the speaker enclosure contains the driving amplifiers. Passive monitors require outboard power amplifiers to drive them as well as speaker wire to connect them. Powered monitors, by contrast, are comparatively more convenient and streamlined single units, which in addition, marketeers claim
14934-515: The standard 3/5a". In 2012, Kef released the LS50 which claimed to be "An innovative concept inspired by the legendary LS3/5a." In 2012, Harbeth released the P3ESR. CNET contributor Steve Guttenberg commented that: "Harbeth's terrific P3ESR is a contemporary equivalent of the LS3/5A. The 12-inch-high speaker feels remarkably solid, and the lovely (real) wood veneer is impeccable. The front baffle hosts
15065-434: The subject. To complement its larger two-way monitors for studio use, the BBC developed a small speaker for near-field monitoring of the frequency range from 400 Hz to about 20 kHz for its outside broadcasting monitoring. The principal constraints were space and situations where using headphones is unsatisfactory, such as in mobile broadcasting vans. Based on scaling tests done in 1968, and detailed audio work against
15196-430: The subjective impression that the speaker is more bass-rich. It has a gently rising frequency response above 5kHz, leading reviewers to notice the sound being a little bright at the treble registers, or that the speakers "reproduce the high-end roughness of solid-state amplifiers mercilessly" thus suggested partnering with valve amplification would be advantageous. A slight nasal quality in the midrange has also been noted in
15327-458: The system to be readily deformed above its glass transition temperature allows polystyrene (and thermoplastic polymers in general) to be readily softened and molded upon heating. Extruded polystyrene is about as strong as an unalloyed aluminium but much more flexible and much less dense (1.05 g/cm for polystyrene vs. 2.70 g/cm for aluminium). Polystyrene is an addition polymer that results when styrene monomers polymerize (interconnect). In
15458-469: The time – there were few high-frequency units available at the time that functioned down to 1.5 kHz, meaning that the woofer must operate in a predictable manner up to about 2 kHz. The BBC developed a two-way studio monitor in 1959, the LS5/1, using a 58mm Celestion tweeter and 380mm Goodmans bass unit, but continually had problems with consistency of the bass units. The successful testing of
15589-406: The time were Eastlake / Westlake monitors with twin 15" bass units, a wooden midrange horn and a horn-loaded tweeter. The UREI 813 was also popular. Based on the almost ageless Altec 604 with a Time-Align passive crossover network developed by Ed Long , it included delay circuitry to align the acoustic centers of the low and high-frequency components. Fostex "Laboratory Series" monitors were used in
15720-479: The time were up to 6dB higher. KEF underwent a program to improve consistency of both drive-unit and the associated crossover, taking care not to alter frequency characteristics or tonal balances. KEF specially redesigned the B110, creating the B110 SP1228 where the surround changed from neoprene to a vinyl compound. KEF also designed a new crossover, designated SP2128. The crossover, also redesigned to accommodate
15851-465: The time – and with live sources. In 1970 engineers came up with the LS3/5, built using the KEF B110 (A6362) and the KEF T27 (A6340) drive units, and a 9-ohm crossover filter . Estimated development costs of the order of £100,000 were said to have been incurred at the time. Approximately 20 units of the LS3/5 were produced in-house. The BBC had initiated tendering to have the LS3/5 made under licence. As
15982-523: The trade name Dylite. In 1960, Dart Container , the largest manufacturer of foam cups, shipped their first order. In chemical terms, polystyrene is a long chain hydrocarbon wherein alternating carbon centers are attached to phenyl groups (a derivative of benzene ). Polystyrene's chemical formula is (C 8 H 8 ) n ; it contains the chemical elements carbon and hydrogen . The material's properties are determined by short-range van der Waals attractions between polymer chains. Since
16113-435: The width of the sweet spot, allowing "accurate stereo imaging for multiple persons". They tend to be used in film scoring environments, where simulation of larger sized areas like theaters is important. Also, studio monitors are made in a more physically robust manner than home hi-fi loudspeakers; whereas home hi-fi loudspeakers often only have to reproduce compressed commercial recordings, studio monitors have to cope with
16244-473: The work of James Bullough Lansing who had previously supplied the drivers for the Shearer Horn in 1936, a speaker that had rapidly become the industry standard in motion-picture sound. He had also designed the smaller Iconic and this was widely employed at the time as a motion-picture studio monitor. The 604 was a relatively compact coaxial design and within a few years it became the industry standard in
16375-412: Was a costlier speaker to build than imagined because tight specifications meant a high failure rate in production – the BBC had specified "the finest, most expensive ingredients and representing an investment of hours of skilled labour". Similar to sealed-box speakers of similar size, the 3/5A has little or no low bass, but the design reinforced its lower register by a boost at around 160 Hz, giving
16506-478: Was also reported that superworms ( Zophobas morio ) may eat expanded polystyrene (EPS). A group of high school students in Ateneo de Manila University found that compared to Tenebrio molitor larvae, Zophobas morio larvae may consume greater amounts of EPS over longer periods of time. In 2022 scientists identified several bacterial genera, including Pseudomonas , Rhodococcus and Corynebacterium , in
16637-408: Was considered potentially fragile because it now had an exposed dome, so a suitable protection grille was found to cover and protect the dome. The tweeter was also surrounded by a thick felt rectangle to prevent interference pattern effects being created by the edge of the cabinet. The crossover also had to undergo change, and the LS3/5 became the LS3/5A in the early summer of 1974. The KEF B110 SP1003
16768-541: Was derived from the LS3/5, which was conceived and developed by the BBC Engineering Department in the early 1970s, when it was under the stewardship of Dudley Harwood. Having found no commercially produced small loudspeaker that met the requirement for naturalness and sonic neutrality, the BBC specifically set out to design a speaker to achieve natural overall sound quality and good dynamic range for monitoring broadcasts in tightly confined spaces. As
16899-422: Was hazardous because engineers unfamiliar with their sonic signatures could make poor production decisions and it was financially unviable to give production staff expensive studio time to familiarize themselves with new monitors. As a result, pretty well every U.S. studio had a set of 604's and every European studio a Tannoy Dual Concentric or two. However, in 1959, at the height of its industry dominance, Altec made
17030-468: Was involved. Art Dudley commented in Stereophile on the LS3/5A's "towering significance" as a bookshelf design. It had become apparent in around 1987 that a number of units already in the field were not up to specification. In particular, it was becoming increasingly difficult to obtain KEF drivers of acceptable tolerances, especially the woofer. Measurements of the 1–1.5 kHz peak of some units produced at
17161-516: Was used simply to check that no obvious technical flaws had spoiled the original recording. As a result, early monitors tended to be basic loudspeaker cabinets. The state-of-the-art loudspeakers of the era were massive horn-loaded systems which were mostly used in cinemas. High-end loudspeaker design grew out of the demands of the motion picture industry and most of the early loudspeaker pioneers worked in Los Angeles where they attempted to solve
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