GB2212696A - A loudspaker system - Google Patents

Description

2'2''/- 'D 'I u A A SYSTEM 1.

The invention- re-lates to a system with, at 'east twe I-v sound -.eproduction, 4 n the Gua 1 j - 1 Z l 2 0 - 0 1 7 o r h -- gIn a u a 1 i -1. y r e n -- -- d; u -- t i c- n, -1) u,;; s -; D e ak: e r ded w- -th --we - -oro7. ore ioud's-neakers.

ystems are U_ ' or m The applcat ion sne----a'--Jze.-J A--.--vers al jows: for the 4 G opt J ma" - zed c ccnvers- ---- all over -he a,,db'-e r-.nge. The -crocessed sgna- must, --- - - 5 two or mere -frequency Passive le intc cudspeaker systems are 1known whch sa' --v4-,si-on I i s carried out by means o- a uass.--,,e el---o+,--dnl-c ci-.c,,,,i--., so called crossover. The,,J-sa,lv-nj-aRes c-' passive '-,--uds-oean--er systems result th-e The fr-equency -A---,enc-,'ence c--0 the at-fects cc-,n the c----e division into the -es-.ec'Uve --ass",.nands c-' th-e signal 1 f aiDr,l ed and the overal- ---ec,ienc-7 chara.--t;-z7--s4,--c of 2s moreo c., v e he louds-oea,-er system. wh- -ably -nlluenced bv -oroduc-"on --c-'--p- nces of in'avou --- L, -- -oarts of 'he crossover. Sc, -'o-example, c! cores, by of co-'s W4t. -Magnet- ona- nc.n-,'-.nea- 14 on s a d d 41 U - - -s-Uort-- - -- ced. T h e air-core ccoils affect th-e function of the crossover b. m u tu a -c 1 i - -so au cou Mzs and are a7 ite ex-,--=ns4-ve. T ',- e e ' e c t r le he -.cn,z -,erm. coff the of oudspeaker systems due to theJr -nR and their agei '- h accuracy of ca-cac.Lt-i -is Renertsill- fficient. 3o.

7 insia -'-he impedance and characteristic sensitivity of all t he loudspeakers used in a systern must be of a-1- 4mately 'he same val-e. -ap-es can crox- j -1 d'-sadvant 2 t 4 - c -the part-ly removed, but i 1 _s alWays t 1 ! - c4 -Y of the c- of t -ossover and 7 2 imen er-- - in hi esu -1-s -Rher 11 ' S 1 O- z - 4 -1 n + -her d- ---Slu------ A.not isadvan-la,7e:

-one dam-oi_nz of the basic resonances of the mmiddle-t C i 2 1 oudspeakers and tweeters, which is caused by of the out-ryl.,,-t immedance t--- at -freauencies outsidle the transmission bands:

of the corresponding passbands.

,'s 'eads to n.'- e st.

Mereased - U modulation di -rt on and lc de t - -J - - 0 charact,e---s-,-'cs of ---- the trans--en'l - - u.:,' s -c e e -- s -- s t e _m s.

A" S-, 4n thei com- catei ----cssove--s, 271 - case of more own which 15) whole systemn.

Active Iouds-oeaker systems are known, which 1, - - i -res-oec-'.-ve 7-oudsneake--s se-carately.

h e y al so eM-O" GY a -- t i Ve f 11 t e r s t o i d e the s i Rnal i _nt o 111- e corres-oonding frequency bands and all the speak-ers, ters usua",-. form, -,owe-- and active: - - f1 - l=c t - t,oRe- --er the necessary -, on--= const - on --ve louds-oeaker s have 1 u n 41 t 'The act- ystems --"o not he A4 "ems, however, t sadvan-tages of the passive syst Ihey ver-, ex-Dens, ve, due to the h- gher number eni t, -- - - - of -jower employed.

: c- 4,z remove e -,)ur-oose o Ihis invent- - --,o '-he -7,'--sa;.van+ 0-0e - - cu s - U - ages and to o: - a ' - eaker system ar- and -p-ss-7e crossover, te -uts wh-cn a' 'east -,wc are ---e connec-ced.

T.n this system the in-ou+ o-^ -" U -;,he corresponding attenuation-correcting means 4- connected to the inpull, of each 1-ouds-oealr-er, the -s of the said attenua- t combined oulliDut.4-on-co-rrec means being connected -,c -,he second of the comnarison amollifier. To the first in-out of the com-carison am-p-lifier the Jinput -1-ermJna' Js connected t' - 1 - - - 1 Uhe out-u+ of the sa4d am-clifier be4-.-R connected to c,- 1 C, 2, c,- -Z,-' -,--he -oass- ve crossover.

m lo the out-out- of the com-car, son am--, --- er the input of.' an adJ i ti ona! U--- - ------ - h -enuation-correcting means may be con-rected e att out-out of which is connected to the second of t he comnarison he 'ouds-oeaker system to the inven-t--n ach-leves, by means of neRa.,--,e feedback, a of values of charc--c-.-,r-Jst--'c sensitivity and impedance. Th e -s are undesirei properts-ies of crosscve-. component ir sufl i c i -- nt lly su -D -1ressed' and lower accuracy of the' vallues is necessary..-k' s -, t h e c o n t- r ibu t i o n t o -ICh e unwanted transient behaviour of -he crossover employed is suppressed, and w4--.h scT-,e -.ypes of crossovers, even the dampling of the basic --esonances of middletone --ouds-eaEers and tweeters is im-nroved.

tl - 1, n-ol-oyi-nR only one power. am-' - 'i er per baf e, the 11 P -, 1, - - - - - - - I'louds-peaker system is advantageous 'r-,m economic ppoint of view as well.

An exam-c-le of a -'l-ouds-oeaKer system a c c -- r d -- n g t o e 1_ n vention will now be deseribed, by way of examu7e, with reference to the accompanying Al --- ings, in wh- d_agrammat-c -.-!-mw-- -ch:

7---;gure I -- gures shows the over-all system, an, - ves 2 and ---J'-----ist:.ate twe alternat.

comi)ar o --F' - 'U i - -4-son amplifier emuloyed.

According to Figure 1 the input terminal 1 is connected to the first input 2 of a comparison 3, the output -4 of which is connected to 1 L - o- 0 a crossove-- E.

n -Du output 7 of the massive crossover 6 the first "' - t h e f r s t 1 louds-ceaker 9 is connecte,:,, -4,--',ie second loudspeaker beinR connected to the second out,-,ut P Of t'll-e -oassive crossover 5. 'he 4--Dut o' '4-s' louds-neaker 9 is -_ -.---- L - U - L - '11 of a '4rst attenuation- connected to the in-out 1 1 cor-,ec.t,-4n-? t-4-pole 12. The 4 Of the second 11 n 0 1 ' l; 5 -he - ' o f a Louds-oeaker 10 is connected to t -.n-out '- -1-ir,o',- 1 5.

sec=l a-i.uenu----,4uion-correc+v-LnR 4- -- 7 -0 of t-he --0,;.rst a-.--Uen.L,.a--4-on-correct-no 0 'Ll 'I -oo'-e ar.' lhe oa--u- secon,,' ats -, e nu a-t i -- -- - c c r r e -- t 4_ n R t -- in c -- e ', ' -- --- c c n n e c t e,-, 'I o lhe secon,:' -:-rjut 2C) of cc=-car4-s--n The ou-,-,,- the comrar4son am--4-04c- -z -'s a-ten,oa+.-; on-correcting --ri tole 8 the out-out 1 0 of t l ' I w ri -- c -,). J. s c o nn e c tu t, o th e s ec o n d 4_ n -c u t o -f t h e com-arison am-c--if--,e-- k L S i p- a -na -D-D c -'.-'.,e -n-1-, -'-erm-na- 1 is th passive crossover Ey means of e 5 of tulne crossover - frequency bands and bwo -- -oud'speakers 9 and;0D.

-'ol-iA-s-.eker 9 v'taRe on the inuut o- o 0 by the secon,,;.

Jn.'-c sent to the innutIs o he -7 the st is atenuated b.

12 and to the -om-car-4so-. 5. Th e 2 ' ' s r e alk- e the secon, ou.

and to the seccnd i---.lat 2.2 of the By the application of negatve feedback, 4 es o Uhe ma-or4-'uy of undesired proper±-- bct.-- -1,11,e 1; - -passive crossover and ampliffier 3 is suppressed and - - L --lgher reproduction quality of the louds-oeaker system 1 i 1 i j 1 i i 1 r, -; 1 - s achieved. Bly the choice cf- c-i" the -, - ' - 1. - attenuation on one off the respective attenuating- corrects-ing tripoles 12,11.S, the -,om-,ensa+lon o-- Iifferences in cha.-9.cter iv---,y and/or stic sensit.

ma n-; -,oud- J ce g tude off tlne Lm-pedan.

- 4 s-oea.'...:ers 0,113 with.out addlitional 'losses is possib By em-o'-lovJnR a+utienua+uon-co-rec.u-Lng tripoles 12,1j with adjustable attenuation, the output Dower radiated, in the respective tra.-sm.--ssJ-cn ban-;s may be - the complem.entary controlled without losses. E -1 Il' !-nt,enua-,--or.-correc,4-n,3- tripc-le e, an n e -a a -1 1 v e f e ed b. a ck- i s i n 'U r o du c e,-, i - ' e f -- e cu e n c Y region above the udio Iband, -,hus securing the high- J_. - -_ of the com-.P--- -4s on ampl e, ---equenCY Stal'J"tY he com-carison amnlifier 3 --,se'-- -s s",.ow-.--n Figure 2 as a non-J-,nver+.-i-ng one, and J.-- as an nve---,ng one.

The '-ouds-.ea'-,--er ssystem to th.e invention is intended '-o7 sound 1 e.

21-1 reDroduction, in zarticular in the s-chere of consumer e" ectronics. Eowever, it- is su--;+,a",-,--!e and convenient for pro-_fessionall applications as well.

r, - A 'loudspeaker system provided a c. ra-i s-n am-ol e- hRv -,R rs' an, a sec or d two nz)ut and a -oassive crossover, to which- at.eas-l 11 are connected, w- erei---- to the input of each loudsneaker an in-out of a res-oec+.4.7e means is connec-led, combined out-outs of which are connected to the second -- rst i i--ou-1- of -'Lhe comDari-son -n-ou-- U ---0 whi ch an i-out term -,a" i - connecte,-7 to the out-cut of which the '-n-ou. of -.he -ass4-7e c--ossoirer is j cc--.ne--+.e..J. _ o ud s al c e r s ys t- e -- a c c 1 n- n c a c- ---; --- m- - t-he - -cut o" 'he compa7ison = t -U to the of a ai,-.enua-'.--Lon-co--"rec-.--ng means, Ithe output of wh--'c'-- LS of connected to the second i-nnu-.'1 I-1- A "o,,ids-Dea'----e- a-cor^-7n,2 to ' or 9 c=structed, ar-ranged and ada-o'.ed to ocerate substuantially as 'nerein desc--4-"'.,ed refeereence to, as shown in, the accompanying d--aw--ngs.

, 5: j- r RmMat i c Published 1989 atThe Patent Office, State House, 66,71 High Holborn, London WClR4TP. Further copies nikybe obtainedfrorn The Patentoffice. Sales Branch. St MaiT Cray, OrpingtoL, Kent BR5 3RL printed by M-uItiplex techniques ltd. St. Ma:7 Cray. Kent, Con. V87 1