CA2002034A1 - Acoustic box for sound transduction - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

An acoustic speaker enclosure including two sound areas separated by a wall to provide medium or medium high and high units. A first area is divided into two chambers approximately equal in size by a sound screen. A speaker or transducer is mounted in a rear chamber and a suitable horn is mounted in a front chamber independant of the rear speaker in such a way that the part of the chamber between the screen and the horn constitutes a pneumatic stabilizer of the membrane of the speaker in the rear chamber and balancing the compression to improve response at low or sub low frequencies. The chamber defined by the horn constitutes an acoustic transformer to increase response in the low frequency range. In the other sound area a biconical horn is mounted with a front part at the entrance of the sound area. The biconical speaker includes a sealed bell at its inner end for phase correction.

Description

ACOIJSTIC l~OX FOl~ SOUNV 'l'l~ANSI)UCTlON ~"" ~``; `

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I)ESCI~II''I`lON

PURrOSE OF TIIE INVENTI()N

This invention is rererred lo an ncour?lic coml~lcx ror sou~ rnlls(luclioll, a box wllere lwo ` ;
independent areas arc adjus~e(l, onc of lllem ns a low solll)(l ul~ mcnlls, ror low rreguencies, ;~
and the oiher one for medium-hi~ll rre~u~llcics or mc(lilllll nl~ rrcgucllci~, imn~al1s~ wilh , i the characterislic that in lhe rirsl casc lhe nte.l is d~vi(lcd intO l~o l-nr~s or chnlllbers sel~araled by a sounder screen where il is adjuslcll lllc lrnl-s(lllccl, I cin~ Ihis one l-laccd in one of the chambers, while the olher one incorl~ores? Ihc nsscml71y Or a hobbill. ~ he SCCOlld casc, i~ means, the medium-high unil or medium and hi~ll il incorl)orcs n biC(!lliCnl bOhl-ill WlliC~ iS comple~ed~
with a dirfuser and a sealed bell ~hal works ns challll-cr Or lhc lrans(l-lccr, I eing a(ljusle(l inside of it.
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BACKGROUN~OFTIIEINVENl'lON ``"` `~ ~ n``

Sound transduclion is lhe rhlal slngc Or lhc cllnill Or l hellolllellolls Ihnl slarls whell an analo~ or digital activ~ted magnelic tape, a disc rccor(lG(I hllo ~roo~cs, or an ol)lically recorded base, is ` - ` ; ``~`
exploted by ils corresponded rea(ler, hl such a wny lhal lhc rcadcr cmils clcclricnlly inlerprelcd signals to be later filtraled, lrealed and aml)li[icd~ l y me.llls Or lhc corr~spolldell~ ~ransducer, in order to be converled inlo a new sound.

Electroacouslic tranducers or sl)enkcls, arc bnscd on a mol-il l-ol-l-in associnlcd ~o ~he corr~s- `; ~ ``
pondent magnet and lo a membrnlle or cone, all assambled on n slll)l~or~ s~ruc~ure.

The menlioned mobil bobbin rcceiYcs ~hc clcclricnl sound si~nill, ~cncrn~illg a variable magnelic rleld that produces repulsions in resl~ccl lo lhc rickl gcncrnlcd hy lllc lixc(l magllet, alld sinse ~his `"
one is joinled lo lhe frame, while lhc bol l-in is jointcd lo Ihe mcllll)ralle or cone~ and also this cone is fixed to tlle rrame, il resulls Ihnl Ihc sllir~s Or ~hc mellliOIlCd bobbill .lrc ~rallsla~ed in~o molions of the membrane or cOIlc"lll(l consecuclllly il Ls r)rodllce(l Ihe corresl)ondcll~ sound when the air masses are shined. ,~

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- 21)0203A

In olher nspects, i~ mus~ be laken in accoulll llult ~l~c mosl impol lanl (lualily ora soull(l lransdllcer is ~hal it must produce a sound ll~c mosl silllilal pnssiblc soun(l ~o Ille onc gcncralcd in ll~e source, and consecuenlly reproducin~ is SOlm(l Will~OIII inlr(!(lllcin~ any dislol lion raclor.

In this way, it has been demonslralc(l llull willl a sole spcakcr il is inll-ossil-lc lo cover all lhe range of audible frecuencie~s, and consccllcnlly il mllsl l-c resorlc(l lo I-i~ dialllclcr speakers ror lhe low rrequencies, known as woorers~ wl~ilc lor l~igl~cr rrcqucncicS il is cmployc(l spcakers Or smaller dismeler, known as Iweelcrs Also it must be taken in accounl ~hal a spcakct emils SoUn(lS inlo Iwo OppO~Cit direCIiallS, OllC Or them considered as rear and ~hc olher onc as lronlal, I-cin~ l)roduce(l in l-elwcen ll~e air volumes contained belween the ~wo parls sollle mixl~lrcs Ihal inlcrrers Illc vil-ralions There is no doubt ~hat solulion lo avoid lhis ploblclll woul(l COllSi~CI in S(`parale bolh parls by a sounder screen, in such a way lhal each onc Or lhc ~encralc(l w avcc woul(l ~o lo dirrerenl sidcs Or it. This screen, denominaled inRnile screen~ is iml~ossil-le lo I e carric(l oul in Ille praclice, and consecuen~ly i~ is resoned ~o ~lle classic acouslic box whcrc il is lricd lo climillalc lllc rear wave Onc o~ ~he charac~eris~ics of ~he acouslic l)0X is Ihe one rclalcd 10 IhC air conlailled inside Or il, because, since it is sealed, ~he movcmenl Or lllc correspolldclll spcaker mellll rane produces a compression of the internal air, bcing lllis onc nc~ ,il lc ir it is cn~ wl~ilc ill tlle contrary case, the mentioned compression Or ~he air will arlecl llle me~ rallc; il mcalls, il will always exist a minimum box volume where al a lower levcl il will l)e nol ol-lainc(l a ~ood rcpro(luclio Consecuently, it is evident thal one or lhe problcllls lo hc solved hl ll1C .ICOUSl;C l-oxes is ils size, and another problem is ~he phases, in SIICIl a way lhal llle dirrcrcnt wavclcngllls will arrive compensated to the lis~eners, pre~sen~ing a pllasc COlllbill.lliOIl very simil.lr lo Ihe original sound wilh the highest possible direclivily.

These problems change according lo lhe acous~ic coml)lcx~ forlllcd by lwo or more lransducers, each one alocaled in ils acoustic bo~, so ir i~ is .lsed oll~doors or illdools i~ will cllall~e accordillg lo the place, depending on ~he acous~ic con(liliollill~ and il will incrc.lsc accor(lill~ ~o llle acouslic power used it each case When they are proffesional acouslic complexes ror places sucll as discollle(llles, audiloriums or outdoors, it is undertood lhat lhe~se acouslic l-oxe~s musl havc a big size and wci~ht, somclhing that complicates bolh lhe transpor~ and lhe assallll)ly.
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'20021~4 '.', DESCRII'TION OF'I'IIE INVEN'I'ION
`:.:' The acoustic box for soun(l Irans(luclioll, cal ricd oul accol ~ling ~o ~llc objeclion or llle inventioll, has been conceived lo solve thesc l~roblclns, orl`elillg sucll a slrllcllllc llull ror silllililr power it presenls a 50% smaller v(~lume lluilll lllosc aclllally cxisilill~ in lhc malkct an(l a 2(~% lower weight, and consecuently lhis iacouslic box~ ~Yilh il sinlilar sizc lo olllcr classical ones~ gives a higher power, a more planc rcsp(!llsc iall(l ialso olrcrs a lowcr dislol~ioll iall(l il consnallt direc~vily, and all lhis as a consccucncc or a bcllcl disll il~ulioll Or lllc sollll(l sl)ccll lllll as il is hcre explaine(l In a more specirlc way, ~he acouslic l)ox conslilllcs a h(lllow l o~ly Ihal il is (IcYkle(l in~o ~wo areas or unils, one of lhem denonlina~e(l lo~v unil an(l ~l~c olhcr onc (lcnolllill<lle(l mediulll-higll or medium and high unit ::
The low unit de~ermines an area dcvi(lc(l inlo lwo parls or cllalllbcn~, as a consecllellce ot an intermediale sounder screen, incorl)ol ing ll~c r ear cl~ambcr a horll, wllicll ils inlerllal moulh is equal or smaller to lhe one of Ihc mcllll)l anc corrcsl~oll(lclll lo Illc Irans(lllcer adjusled on the referred sounder screen, trans(lllccr Illal il is l)lace(l insi(le lllc olhcr challlber By olher part, ~be ; ~ -mouth of the rererred lransdllcer is also eqllal or smaller lo lhc cxlcrnal one of llle horn This disposilion and physical slruclurc or lhe mellliolle(l coml)nllcllls allow~s a~pneumatic stabili-zation of lhe lransducer meml ranc, balancillg the rear wci~hl an(l giving a beller raised work in ;~
lhe exlreme low or sub-low, conslillllillg also all acouslic lriallsrormcr ~l~al increases lhe capacily in lhe low ones in alignemenl in respccl lo lllc final responsc The pneurnalic slabilizer, consliluled by lhe p arl or lhc chaml)cr Ihal il is belween lhe sounder ~;
screen and lhe horn, allows the reduclion or llle lolal volumc of lhe arca willlolll producin~ any acoustic short-circuil, il means, hllllohilizalion Or lhc lrans(lllccr mcllll)rallc . .
Referred lo lhe medium-higll uniL or mcdium and lligb, lhis one inclll(les a horll, prererably biconical, where lhe lwo parts Or Ws horn are joine(l hy ils smaller l ase The parl of horn considered as lhe inlcrllal onc is cxlcn(lc(l l~crill~clrically in a wing which -~
conslitutes a support-mean for a biconicfll dilrllser iall(l ror a scialc(l I-cll lhal works as ia chamber of lhe lransducer which il is adjusled on llle r ercrrcd Willg of tllC inlcrllal part o~ lhe horn 'i , . . ~.
This incorporated biconical ditfuser WOI ks as il l)hasc corrcclor an(l collaborales in the dislribulion '~
Or lhe polenlial in a verlical way ~ ~

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20020~4 . . .

DESCR11'TION OF TIIE DRAWIN(l~

To complete this description and in or(ler lo hcll) lo a hcller un-lcl sntlll(lillg Or lhc characterislics of lhe invenlion, it is joined lo lllis dcscriplivc l-rochul c~ as a wl1ole pal l, a sole slleel Or plalls, where as an illustrative an(l non-liltlilalivc cllaractcr, il luls bccn rcl)resclllc(l a lransversal sccfion of the acouslic box with the componcllls llmt rornls il.

PREFERRED REALIZAT10N OF 'I`IIE INVEN l`lON ~ ~:

As it can be seen in lhe figurc, it is observe(l how llle acousfic l-ox or llle invelllioll incltlde~s lwo areas 1 and 2, tolally independcnt an(l scpal aled l!y all in lerllle(lia te wall 3, areas tl~al conslilules the corrrespondent units Or low and medium-iligll or me(lillm an(l higll.

The area 1, or low unit, is devided inlO two challlbers 4 an(l 5, apro~imalely all(l prereral ly equal, by means oE a sounder screen 6, being lllis OllC c(luippe(l wi~h Ille correspoll(lcll(l hollow lo adjust the transducer 7, which ofrers a rcar coml)ressioll wci~hl showll hy llle arrows 8 in lhe chamber 4, while in the rear part il incorporcs a horll 9 ~lml coul(l be paral)olic~ conical~ e~pollelllial or hyperbolic, that do not congeniate wi~ llc trans(lllccr 7, beill~ lllis one adjuslcu in lhe arca 1, as it is shown in the rlgure.

The mentioned horn 9, presenls an in~crnal molllll t(), lhal musl bc c(lual or smallcr lo the membrane moulh of the lranducer 7, while lhc m()ulllll or lhis lasl onc mu.sl l-c cqual Or smaller to the external mouth 11 Or Ihe hom 9.

As a consecuence oE the adjusting of lhis horn 9, in lhc chaml-cr S il is also (Iclemlined two sub-chambers, one of lhem in the horn 9 and Ihc screen 6 an(l ~l~e Onc rcrerred wilh 5' and lhat ` ~:
corresponds to the hole determh~ed by lhe l~orn 9, in such a way lllal lhc gcneral chamber 5 is the addition of the menfione(l inlernal challll-el all(l Or lllc exlernal clualllbcr or rercrcnce 12 Or the horn.

The horn determined between this horll 9 an(i lhe soun(ler screen 6 conslilu~es a pneumafic stabilizer of the transducer membralle 7, balancillg ~he rear wcigllt 8 an(l incorporing a better shape in the extreme low or sub-low, while llle parl Or lhe challlbcr 5` or llle correspondel1t lo lhe horn 9 constituîes an acouslic transrormcl lhal elcvalcs lhe capacily in lhe low ones~ in alignament in respect to the final response.

200Z034 ~ ~ ~

In this way, the berore mcllliollcd l~ncllllla~ic slnl~ilizer allnws ~llc r e(luclioll oï ~ olal volumc of the area, wilhout produchl6 acouslic shol l-cil cuil~ il mcalls, inlllol-ilizalioll Or the mcmbrane of the lransducer 7. ` "
~ : ' In relnlion wilh ~he arca 2 or mc(liulll~ ll Or mc(li~ an(l hi~ll tlllil, illSidC Or il, i~ is de~ermille(l ~ `
n chamber I2, and in il, il is a(ljtlslc(l fl hiCOlliC.ll h01 n COll~CIinllc(l hy lWO parls 13 alld 14, johle(i `- `
by its smaller bases, wilh lhe char.lclel islic lhnl lhc pal l of Illc hol n 1~ is Illc Onc Ihat it is adjuste(l ` "`
to lhe mounlh of the arca 2"all(1 lo do il, Ihis pnrl 14 of Illc h(-lll, lucscllls ils rear l~or(ler ~ ` `
bordered according lo lhe refcrcllce 15, showll in Ihc refcrrc(l fi~urc~ .

The inletnal part oE lhe horn 13, is cxlell(lcd hl R Will~ lf~, cnnslilulillg a scal ror lhe transducer 17 and a support ror the bicollical dirrtlser 18, scparalillg Ihe hi~er p3rl of il l y a central chailI `
lhat by means oE lhe cmergillg an(l radial hlallclles is joillcd lo Ihc win~ Ifi, also supporling a `
sealed bell I9 lhat works as a challlhcr of Ihc ~rialls(ltlccr 17.
. .i , ~, According to this structure, the bicollical dirrtlscr 18 works as pllasc correclor all(l joinly wi~h part of the area 13, dislributes lhe polenlial hl a verlicall way in Ihe narrowlless Ihal rorms the biconical 13-14 o~ this horn. This diffuscr Ig mtlsl he as ncar as pc)ssil)lc lo ~hc p islon of lhe lransducer 17 without obstructing the maximum movcmclll of il. ` -The rear weight of lhe menlioned Iralls(ltlccr l7 kccps conlahlcd hl Ihe challIl)er 20 formed by the sealed bell I9, consliluling a synlollizc(l arca, while lhe frolll wei~h~ keeps distribllled in benefil oE direclivily and of lhc major prcscllcc hl rcsl)ecl lo thc ~olal spectrllm by llle diffuser ` `
and its horn. ; `
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In a maximum reduclion of the chnllll)cr 4 corrcspoll(lell~ lo lhc Rrsl unil or area 1, in respecl lo the addition oE the olher lwo cllaml)crs or this arca 1, il is rorsecn hollows or whIdows hI lhe same `
inlermediale wall 3 that separalcs l)olh arcas or ullils.

Il is nol considered as necessary lo do a lon~er dcscril)lioll hl ordcr lo hc un(lersloo(l by a perso skilled in this area and lo underslan(l Ihc advalllages of il.
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'rhe malerials, shape, size and disposilioll Or llle elcmellls COtlkl I)C varic(l, if il me.llls no suslanlive alleration oE lhe invenlion.
: . :, The terms used in the descriplinn of lhis brocllulc musl he lakcll hl lhe ~idcst possihleway and `~` `
in a non limilalive way.

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Claims (3)

1. An acoustic box for sound transduction, including two sound areas 1 and 2 separated by the correspondent wall 3, forming the are 1 the correspondent low unit, while the are 2 constitutes the medium-high unit or medium and high unit, and incorporing in both areas the respective transductor to convert the correspondent signals into sound, essentially it is characterized because the are 1 is diveded into two chambers 4 and 5, aproximately equal, by means of a sounder screen 6, where it is assambled to correspondent transducer 7, being be foreseen that in the rear chamber 5 the assambly of a horn 9 duly adjusted, which it is independent of the tranducer 7, in such a way that the part of the chamber placed between the screen 6 and the surface 9, constitutes a pneumatic stabilizer of the membrane of the transducer 7, balancing the rear compression weight 8, and giving a better raised work in the extreme of low or sub-low, while the chamber determined by the horn constitutes an acoustic transformer that increases the capacity in the low ones in alignation in respect to the final response; with the characteristic that the area 2 that constitutes the unit of medium-high or medium and high incorpores a biconical horn formed by two parts 13 and 14 joined by its smaller bases in such a way that the front part of the horn 14 is frontly extended in a seized way 15, through which it is assambled on the entrance of the correspondent area 2, while the part 13 is extended in a wing 16 which contitutes a fixing mean of a biconical diffuser 18, of the transducer 17 and of a sealed bell 19, all this in such a way that the biconical diffuser 18 acts as a corrector of the phases and as a mean to distribute the potential in a vertical way.

2. An acoustic box for sound transduction according to claim 1, characterized because the internal mouth 10 of the horn 9 correspondent to the first area 1 has a diameter equal or smaller to the mouth correspondent to the membrane of the transducer 7, and this last one is equal or smaller to the external mouth 11 pertening to the mentioned horn 9.

3. An acoustic box for sound transduction, according to claim 1, characterized because the biconical diffuser 18 of the second area presents its bigger joining bases separated by a central chain from which derives branches to vinculate the complex to the correspondent wing 16 of the internal part 13 correspondent to the biconical horn, being forseen that the chamber 20, that forms the sealed bell 17, determines the mean to content the rear weight of the transducer 17, forming also a syntonized area, while the frontal weight of the mentioned transducer 17 keeps distributed in benefit of directivity.