sub complete dedicated reproduction low pitched audio frequencies known bass typical frequency range consumer products professional live sound approved systems intended augment low frequency range covering higher frequency bands mounted enclosure wood capable air pressure resisting come variety designs including bass port passive enclosure infinite horn loaded designs representing unique respect efficiency size cost passive driver enclosure powered external active include built developed 1960s add bass response home stereo systems came greater popular consciousness 1970s introduction movies earthquake produced loud low frequency sounds large advent compact cassette compact disc 1980s easy reproduction deep loud bass longer limited ability record stylus track groove producers add low frequency content recordings 1990s dvds increasingly recorded surround sound processes included low frequency effects channel heard home theater systems 1990s increasingly popular home stereo systems custom car audio installations systems 2000s universal sound reinforcement systems concert venues history september received patent numbered specifically designed augment low frequency range modern stereo systems able reproduce distortion free low frequencies cycles second specific objective invention provide portable sound provide high fidelity reproduction low frequency sound waves giving indication portion room marketed trade early 60s mid-1970s utilized recording artists era notably bassist bassist speaker technology utilized select theaters reproduce low pitch frequencies blockbuster movie earthquake late 1960s favorably reviewed publications including news early enclosure home studio use separate bass speaker designed prototype physicist airline pilot garage design second winding custom inch driver provide control information offered sale expensive complete listed stereo review found outside investment reorganized infinity reviewed positively magazine winter issue infinity reviewed highly magazine developed late 1960s president los_angeles business partner owned high end audio store los_angeles told store high end speakers complained lack bass response designed powered reproduce frequencies low speakers convey infinity range speaker system developed 1960s cover lower frequency range handle adequately use recording session mixing dan album logic recording engineer arranged bring prototype design modifications years 1970s 1980s engineer record producer served consultant golden ears design crossover network partition frequency spectrum attempt reproduce frequencies high effective range main speakers need handle frequencies low effective range received great deal publicity movie earthquake released initially installed theaters system large driven racks triggered control tones printed audio tracks film positioned audience film screen placed rear audience platform powerful noise energy range generated level sound pressure level abbreviated new low frequency entertainment method helped film box office success systems assembled installed systems select theaters films use effect include naval battle epic midway speakers exotic popular different sizes capabilities sound output owners rpm singles loud deep bass limited ability record stylus track groove solved problem reel reel tape players capable delivering accurate naturally deep bass acoustic sources synthetic bass found nature popular introduction compact cassette possible add low frequency content recordings satisfy larger number consumers home grew popularity easy add existing speaker easy position hide construction features enclosure design use speaker drivers typically diameter uncommon use larger drivers single prototype large fabricated smaller end spectrum drivers small depending design enclosure desired sound pressure level lowest frequency targeted level permitted distortion common driver sizes sound reinforcement models respectively largest available sound reinforcement drivers commonly seen efficiency speaker driver given formula parameters deep low frequency extension common goal small box volumes considered desirable low efficiency constraints require considerable power individual drivers example sealed speaker box box volume achieve given proportional formula formula decrease box volume decrease efficiency sub similarly speaker proportional formula efficiency proportional small improvements low frequency extension driver box volume result significant reductions efficiency reasons typically inefficient converting electrical energy sound energy combination factors accounts higher power output requirement greater power handling drivers enclosure variations bass designs increase efficiency driver enclosure system helping reduce power requirement designed number enclosure approaches bass acoustic suspension infinite horn loaded tapped horn transmission line enclosure type advantages efficiency increase bass extension cabinet size distortion cost typically constructed mounting cabinet medium density oriented strand board aluminum stiff materials high air pressure produce cabinet require internal distribute resulting forces smallest typically designed systems largest common concert sound reinforcement systems dance club sound systems example large concert enclosure 1980s era bass cube system drivers example uses bass horn loads driver foot long folded horn folded horn type typically produce deeper range greater efficiency driver enclosure lacks horn experimental fixed installation horns constructed brick concrete produce long horn allows deep sub bass extension output level increased increasing cone surface area increasing cone excursion large drivers require large drivers large unfortunately high excursion high power levels tends produce distortion inherent mechanical magnetic effects electro dynamic drivers common sort conflict goals fully resolved designs necessarily efficiency system directly proportional cabinet volume cube frequency applies frequency range frequency response frequency response specification speaker describes range frequencies musical tones speaker reproduce measured typical frequency range professional concert sound system typically operate approved systems operate vary terms range pitches reproduce depending number factors size cabinet construction design enclosure driver specifications frequency response depend wholly relevance accompanying value measurements taken wider tolerance wider frequency response example system discontinued system designed movie theaters frequency response measured boundary narrower frequency response measured boundary vary regard sound pressure levels distortion levels produce range abyss example reproduce pitches pitch lowest notes huge pipe organ foot pipes abyss lowest frequency maximum limit distortion meters means person choosing needs consider lowest pitch sub reproduce active include dedicated cabinet include user allows boosted reduced output particular frequencies vary simple boost switch fully meant detailed speaker room correction systems supplied microphone measure room response automatic correct combination location room response minimize effects room modes improve low frequency performance passive driver enclosure include incorporate internal passive filter frequency determined factory generally party power taking active earlier signal chain box packages come passive cabinet multi channel high end home theater systems use passive format popular professional sound industry adjust room response system designers active include degree compensate known performance issues desired low end roll rate addition include low pass filter prevents higher frequencies reaching driver example listener main speakers usable filter set works typical filters involve overlap frequency ranges steep filter generally desired crossover section include high pass filter prevents driver attempting reproduce frequencies safe capabilities systems use attempt correct room frequency response irregularities unable achieve flat frequency response listening locations resonance standing wave patterns low frequencies nearly rooms careful positioning room help frequency response multiple manage general response arranged room modes evenly single allowing effective phase control changing relative phase respect speakers help minimize unwanted destructive acoustic interference frequency region covered main speakers help frequencies create problems frequency response generally provided adjustment phase control circuits simple reversal switch complex continuously variable circuits continuously variable phase control circuits common found electronics projects phase controls allow listener change arrival time sound waves relative frequencies main speakers crossover point similar effect achieved delay control home theater receivers phase control found actually switch allows users reverse relative audio signal given type control allows phase source signal degrees phase phase changed moving closer listening position practical active use feedback mechanism based cone movement signal sent voice feedback signal derived comparison input signal versus actual motion cone usual source feedback signal turns voice attached cone based placed cone advantage implemented design reduced distortion making smaller enclosure sizes possible primary cost complexity controlled primary mechanism sound reproduction avoids normal voice combination favor high speed belt driven design increases output power reduces distortion virtually loss output results increase voice voice called power compression feature allows high power operation extended periods time nominated drive design model applications home audio use bass capability main speakers allows smaller sacrificing low frequency capability necessarily provide superior bass performance comparison large conventional ordinary music recordings typical lack low frequency content sources recordings substantial low frequency content conventional ill equipped handle help especially high levels music pipe organs meter bass pipes large bass drums symphony orchestra recordings electronic music extremely low synth bass parts bass tests bass songs frequencies sufficiently low easily localized humans stereo audio systems feature channel single placed center affecting perceived sound stage sound produced difficult intention system use small main speakers stereo surround sound movie tracks hide furniture table augment existing speaker save having handle destroying low frequencies high levels effect possible restricted low frequencies usually taken localization possible restricted lower maximum frequencies higher upper limits easily localized making single impractical users add high levels low bass desired original recording case house music enthusiasts package includes satellite speakers purchased separately built cabinet conventional speaker system instance floor standing tower speakers include driver lower portion cabinet physical separation satellite speakers allows placement location sub bass frequencies particularly sensitive room location room modes best position likely satellite speakers located greatest efficiency best room air volume placed corner room far large room openings closer listener possible low bass frequencies long little difference information reaching listener left right ears readily localized low frequency information sent sound tracks carefully mixed single channel possible cancellation low frequencies bass information channel phase physically separate satellite arrangement popularized speaker systems audio series low cost home theater box systems advertise integration simplicity particularly low cost home theater box systems boom boxes inclusion little marketing device unlikely small built compact plastic cabinet better bass performance designed conventional typically larger speakers cabinet mere use term guarantee good extended bass performance better termed bass drivers small produce deep bass poorly designed systems leave higher meaning handles frequencies ear use sound source localization introducing undesirable localization effect usually poor crossover designs choices high crossover point insufficient crossover slope computer home theater systems localization comes port noise typically large amounts distortion design home sold individually usually include crossover assist integration existing system car audio automobiles suited hidden approach space limitations passenger compartments possible circumstances fit large drivers doors installed trunk seat space car audio enthusiasts compete produce high sound pressure levels confines vehicle cabin dangerously high wars drawn attention general competitions sound quality gained equivalent popularity cars able play normal music drive normally designed solely competition non competition capable generating high levels cars small volume typical car interior high sound levels cause hearing loss exposed extended period time 2000s car audio manufacturers produced non circular shapes manufacturers including sony shapes typically carry sort distortion penalties situations limited mounting space provide greater cone area assuming constant greater maximum output important factor square sub round sub argument effects enclosure sealed enclosure maximum displacement determined formula stands volume displacement linear excursion speaker capable cone area sub parameters measured found driver specifications cinema sound introduction movie theater owners began installing permanent systems track channel film sound format introduced channels stereo reproduction low frequencies introduced dedicated cinema model tuned starting certification cinema sound experience parameters good audio watching films including requirements performance levels isolation outside sounds noise interfere listening experience helped provide guidelines cinema owners wanted individual cinema neighbors making isolation difficult specific cinema models appeared early 1990s digital channel film sound format incorporated single channel point surround sound boston based blames complaints modern movies loud says possible loud relatively bass movie sound levels limited distortion capable systems low frequency high levels sound reinforcement professional audio rock concerts performances festivals similar events capable high output levels low distortion reflected design attention given recent years applications sound reinforcement public address systems dance club systems concert systems consumer applications home use considerably demanding smaller listening space lower levels universal professional sound applications live concert sound churches theme parks movie theatres certified standard include high capability professional applications require designed high sound levels multiple drivers respectively drivers small occasionally generally horn loaded number concert depends number factors including size venue indoors outdoors low frequency content band sound desired volume concert design construction direct versus horn loaded small bar use single direct inch sub cabinet large dance club row twin inch largest stadium venues large number example tour uses double box perimeter central circular stage placed underneath ring shaped stage central main stage main speakers flown ceiling venue chain flying points attachment points built professional flown stacked ground near stage inch typical concert system consumer medium density oriented strand board plastic dense material professional built materials commonly construct permanent installations density relatively high concern permanent installation thick birch faced oak touring typically built thick void free baltic birch finland estonia russia greater strength frequently transported naturally baltic birch coated carpet thick paint spray truck greater touring typically designed features facilitate moving enclosure wheels bar handle handles protective speaker direct style metal plastic protection protect finish slid hardware facilitate corners flying stage rigging 2000s small mid size designed bands live sound use applications powered integrated power models typically built crossover models metal reinforced hole speaker stand mounted range range system professional concert sound system design incorporated seamlessly main speakers stereo range system active crossover system receives signal main stereo mixing console mix bus frequencies desired balance main sound system stereo stereo channel derived crossover stereo mix depending crossover model fed instead incorporated range system concert supplied signal separate mix bus mixing console auxiliary sends configuration called fed observed significantly reduce low frequency build concert sound system stage number picking low frequencies having different phase relationships low frequencies fed method greatly reduces number sources feeding include instruments desired low frequency information sources kick drum bass guitar keys signal sent makes greater clarity low punch fed stereo desired auxiliary mix buses directional bass thumb pattern end fire placed enclosure nearest listener delayed order low frequency energy focused audience area stage low frequencies people outside event space variety techniques developed concert sound turn naturally radiation directional pattern techniques include setting vertical array combinations delay setting delay shaded system vertical array rigging vertical array focuses low frequencies forward greater lesser extent depending physical length array longer directional effect lower frequencies pronounced vertical dimension yielding radiation pattern wide tall helps reduce low frequency sound bouncing ceiling indoors assists external noise complaints outdoors rear delay array array pattern horizontally takes channels processing change required physical space method called array pattern directional methods method enclosure orientation stage delays maximum cancellation target frequency stage implemented reversing physically positioning enclosure face method reduces forward output relative tight packed flat fronted array solve problems unwanted low frequency energy coming stage compared end fire array method axis energy pattern control audience predictable cancellation effect spans range slightly octave second method rear delay array combines end fire reversal positioned drivers spaced quarter apart rear enclosure inverted delayed maximum cancellation stage target frequency method output power directed audience compared directional methods end fire array end fire method called forward steered places drivers rows destructive interference reduce emissions sides rear separate positioned quarter target frequency frequency wanted stage desired audience row delayed row related speed sound air typically arrival time sound energy near simultaneous audience perspective canceled large degree offset sound wave arrival times target frequency achieve rear forward sound summed line technique end fire came widespread use european live concert sound end fire array trades output power requires output power tight packed flat fronted array sixteen rows stages ultra music festival reduce low frequency interference neighboring stages physical size end fire array concert venues able implement output pattern suffers axis shaped adjusting frequency response row delay shaded array long line placed horizontally edge stage delayed center fire prior ones flanking fire prior neighbors continuing fashion reached outside ends row method helps counteract extreme horizontal pattern seen horizontal array delay virtually array directional enclosure enclosure designs rely drivers facing sides rear order achieve degree end fire drivers positioned single enclosure houses driver bass instrument rare cases sound reinforcement bass instrument electric bass players synth bass players bands mid size venues bars standard bass guitar speaker keyboard provide sufficient sound pressure levels onstage monitoring regular electric bass low lowest note standard bass guitar designed range goes cases performers wish extended sub bass response available standard instrument speaker use electric add huge guitar mainly add immense mainly extension sub operated lower volume main bass bass guitar players use include performers play extended range include low string play styles powerful sub bass response important sound funk latin gospel etc bass players perform stadium size venues large outdoor venues keyboard players use stage monitoring include electric organ players use bass pedal keyboards low synth bass players play sub bass parts low keyboard instruments onstage synthesizers produce lowest pitches unlike traditional electric piano electric organ lowest notes low low respectively synth fixed lowest octave synth player add lower octaves patch pressing octave button produce pitches limits human hearing concert sound manufacturers suggest bass instrument suggests concert series square foot enclosure inch drivers bass instrument performers use concert sound onstage monitoring like powerful sub bass sound onstage sound engineers find use large drivers onstage instrument monitoring problematic interfere sub bass sound bass bass felt sub bass augmented unlike typical driver produces vibrations produce low frequency vibrations designed felt individuals touching indirectly piece furniture wooden floor recently emerged device class called variously bass butt throne attached seat instance drummer throne gamer chair car seat home theater seating vibrations driver transmitted body ear manner similar bone connect like normal attached large flat surface instance floor platform create large low frequency area transmission low frequencies feet efficient seat advantage low frequencies allow listening environment filled loud low frequency waves helps concert drummer monitor kick drum performance stage powerful low frequency waves monitor having monitor bass enables drummer lower sound pressure levels exposed performance home cinema use bass help user avoid disturbing nearby apartments rooms powerful sound effects explosion sounds war simulated earthquake adventure film heard critics argue felt vibrations disconnected experience claim music satisfying butt sound effects critics claimed bass loud sound effects distract listener world record claims varying measures base claims said world largest lowest model completed march georgia military request project waves distance designed reproduce continuous wave generate distance meters music measured horn mouth generate constant wave tone hours day seven days week extremely low distortion flat frequency response built container feet long feet square container doors swing open reveal tapped horn driven long throw inch speaker drivers powered manufacturer claims foot sheets construction wrote double thickness sheets convenience diesel generator housed enclosure supply electricity external power unavailable constant tone output capability designer wrote target meters essentially fictional burst peak nonsense pro sound like death signal car sound contests annual convention march barred making loud demonstrations power concerns damaging building instead single electrical circuit safety visitors allowed step inside horn acoustic powered reproduced low level waves royal device custom installation claimed world biggest custom installation italy primarily bricks concrete sound material consisting embedded foundation listening room horn loaded floor mouth square meters horn length meters cavity meter floor listening room driven inch drivers millimeters voice designers assert floor mouths horns additionally loaded vertical wooden horn expansion room ceiling create power wave listening position inch single inch diameter driver designed help driver intended break sound pressure level records mounted road vehicle calculated able achieve built driven motors connected somewhat like engine cone diameter inches held place inch surround inch peak peak stroke created way air displacement cubic inches capable generating waves motor speeds response audio signal play music driver mounted owned powerful applied reinforcement damaged vehicle helped project driver called thunder million unfinished vehicle entered competition complaint lodged computer control motor instead controller leads touched hope motor speed set correctly drive shaft broke positive stroke created interior pressure wave concept design inch shown public heaviest production intended use automobiles audio features inch diameter cone known upwards sent dual voice moving weighs pounds aluminum heat sink featured television ride
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