當(dang)會議系統音響設備故障時，該(gai)如(ru)何是好(hao)?現(xian)在(zai)，小編就為(wei)大家(jia)簡單的介紹(shao)一下，會議系統(tong)音響設備在(zai)發生(sheng)故障的時候(hou)，該(gai)如(ru)何去判斷和(he)排(pai)除。

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一、會議系統音響無聲故障的判斷與排除

1、檢查(cha)所(suo)有設(she)備是(shi)(shi)否(fou)都(dou)已開啟(qi)，各(ge)設(she)備的音(yin)量控(kong)制鈕是(shi)(shi)否(fou)都(dou)已調到合(he)適位置(zhi)，調音(yin)臺上各(ge)通道路徑開關(guan)是(shi)(shi)否(fou)已選通，檢查(cha)各(ge)連接(jie)線是(shi)(shi)否(fou)已連接(jie)正確、可靠(kao)。

2、如(ru)還無(wu)(wu)聲(sheng)(sheng)則(ze)(ze)(ze)(ze)需逐級(ji)檢(jian)(jian)(jian)查(cha)(cha)，可(ke)以從(cong)(cong)后(hou)向(xiang)前(qian)逐級(ji)檢(jian)(jian)(jian)查(cha)(cha)，也可(ke)從(cong)(cong)前(qian)向(xiang)后(hou)逐級(ji)檢(jian)(jian)(jian)查(cha)(cha)。從(cong)(cong)前(qian)向(xiang)后(hou)查(cha)(cha)時，首(shou)先用(yong)(yong)(yong)監聽耳(er)機(ji)檢(jian)(jian)(jian)查(cha)(cha)信號(hao)是(shi)(shi)否(fou)已進人調音臺，然(ran)后(hou)可(ke)以用(yong)(yong)(yong)電壓表、萬用(yong)(yong)(yong)表逐級(ji)檢(jian)(jian)(jian)查(cha)(cha)，直(zhi)至查(cha)(cha)出(chu)無(wu)(wu)聲(sheng)(sheng)的(de)一級(ji)并(bing)判斷是(shi)(shi)設(she)備(bei)(bei)無(wu)(wu)輸出(chu)，還是(shi)(shi)連線有問題(ti)。如(ru)確屬(shu)設(she)備(bei)(bei)故(gu)(gu)(gu)障(zhang)，則(ze)(ze)(ze)(ze)應更(geng)換(huan)備(bei)(bei)用(yong)(yong)(yong)設(she)備(bei)(bei)以救急(ji);如(ru)果(guo)屬(shu)于(yu)周(zhou)邊(bian)設(she)備(bei)(bei)出(chu)現(xian)故(gu)(gu)(gu)障(zhang)，在沒有備(bei)(bei)用(yong)(yong)(yong)設(she)備(bei)(bei)的(de)情(qing)況下，可(ke)以直(zhi)接(jie)將(jiang)出(chu)故(gu)(gu)(gu)障(zhang)的(de)周(zhou)邊(bian)設(she)備(bei)(bei)跳(tiao)過(guo)。例(li)如(ru)均(jun)衡器出(chu)現(xian)故(gu)(gu)(gu)障(zhang)了(le)，則(ze)(ze)(ze)(ze)可(ke)以將(jiang)輸人到均(jun)衡器的(de)輸人線插頭拔出(chu)來加到后(hou)一級(ji)設(she)備(bei)(bei)的(de)輸人插座(zuo);如(ru)果(guo)是(shi)(shi)調音臺的(de)某一輸人通道(dao)(dao)出(chu)現(xian)故(gu)(gu)(gu)障(zhang)，則(ze)(ze)(ze)(ze)可(ke)以換(huan)一路輸人通道(dao)(dao).直(zhi)到活動(dong)結束后(hou)再更(geng)換(huan)設(she)備(bei)(bei);如(ru)屬(shu)連接(jie)線有問題(ti)，則(ze)(ze)(ze)(ze)在急(ji)用(yong)(yong)(yong)時先換(huan)備(bei)(bei)用(yong)(yong)(yong)線，然(ran)后(hou)有空時再修(xiu)理(li)設(she)備(bei)(bei)和連接(jie)線。對于(yu)設(she)備(bei)(bei)，如(ru)自己不熟(shu)悉設(she)備(bei)(bei)內部(bu)結構、原(yuan)理(li)時不要輕易動(dong)手(shou)修(xiu)理(li)，以免小故(gu)(gu)(gu)障(zhang)變成大(da)故(gu)(gu)(gu)障(zhang)當用(yong)(yong)(yong)電容麥克風時，還應檢(jian)(jian)(jian)查(cha)(cha)幻像電源是(shi)(shi)否(fou)加上。

二、會議音響系統中哼聲大的判斷與排除

哼(heng)(heng)(heng)聲(sheng)往(wang)往(wang)是(shi)由于(yu)(yu)接(jie)地(di)(di)(di)(di)(di)(di)不(bu)良或(huo)不(bu)對，系(xi)統的(de)設(she)備不(bu)在(zai)同一路電(dian)(dian)網上，地(di)(di)(di)(di)(di)(di)電(dian)(dian)位嚴重(zhong)相差引(yin)起的(de)，而連(lian)接(jie)線(xian)的(de)屏(ping)蔽層脫焊或(huo)屏(ping)蔽線(xian)接(jie)得不(bu)對而形成(cheng)地(di)(di)(di)(di)(di)(di)電(dian)(dian)流回(hui)路，也會(hui)(hui)引(yin)起哼(heng)(heng)(heng)聲(sheng)大(da)。所以應著重(zhong)檢(jian)查這些方(fang)(fang)面，必要(yao)時應加隔(ge)離(li)用音頻變(bian)壓器，以便把(ba)前后級設(she)備間(jian)的(de)“地(di)(di)(di)(di)(di)(di)”斷開，而信號(hao)仍(reng)然暢(chang)通(tong)。尤其(qi)是(shi)在(zai)兩個系(xi)統之(zhi)間(jian)相連(lian)接(jie)時，往(wang)往(wang)會(hui)(hui)由于(yu)(yu)兩個系(xi)統不(bu)用同一電(dian)(dian)源(yuan)而引(yin)起兩個系(xi)統之(zhi)間(jian)的(de)地(di)(di)(di)(di)(di)(di)電(dian)(dian)位不(bu)同，有時甚至(zhi)非常(chang)嚴重(zhong)，從(cong)而產(chan)生明顯的(de)哼(heng)(heng)(heng)聲(sheng)。對這種(zhong)原因引(yin)起的(de)非常(chang)容(rong)易判斷，只要(yao)將(jiang)(jiang)兩個系(xi)統之(zhi)間(jian)的(de)連(lian)接(jie)信號(hao)線(xian)插(cha)頭從(cong)一個系(xi)統拔掉，哼(heng)(heng)(heng)聲(sheng)馬上會(hui)(hui)消失。如(ru)果確認哼(heng)(heng)(heng)聲(sheng)是(shi)由于(yu)(yu)兩個系(xi)統電(dian)(dian)源(yuan)的(de)地(di)(di)(di)(di)(di)(di)電(dian)(dian)位不(bu)同引(yin)起的(de)，則可以采取將(jiang)(jiang)兩個系(xi)統的(de)“地(di)(di)(di)(di)(di)(di)”隔(ge)離(li)的(de)方(fang)(fang)法，通(tong)常(chang)用加隔(ge)離(li)用音頻變(bian)壓器來(lai)達到目的(de)對隔(ge)離(li)用音頻變(bian)壓器的(de)技術要(yao)求是(shi):

①一、二次繞組用同樣規格的導線繞制，圈數(shu)比為1：1;

②輸人阻抗(kang)和(he)輸出阻抗(kang)均(jun)為600Ω;

③諧波失真不大于10%;

④頻率響應在40Hz~16kHz范圍(wei)內優于士0.5dB;

⑤功率最好不小(xiao)于100mW。

三、會議音響系統中削波失棄的判斷與排除

首先檢查各設(she)(she)(she)(she)備(bei)(bei)上的(de)(de)削波(bo)指(zhi)示燈是(shi)(shi)否亮(liang)著，如并未發現削波(bo)指(zhi)示燈連續亮(liang)，則(ze)(ze)可以(yi)選(xuan)擇系統靠中間(jian)的(de)(de)一臺(tai)設(she)(she)(she)(she)備(bei)(bei)把音(yin)量降低幾個dB.以(yi)判(pan)(pan)斷是(shi)(shi)該(gai)設(she)(she)(she)(she)備(bei)(bei)的(de)(de)前(qian)面(mian)已(yi)有削波(bo)失(shi)真，還是(shi)(shi)在該(gai)設(she)(she)(she)(she)備(bei)(bei)后面(mian)才(cai)產(chan)生(sheng)的(de)(de)削波(bo)失(shi)真。如此(ci)經過幾次調節(jie)音(yin)量控(kong)制(zhi)器，即可判(pan)(pan)斷削波(bo)來自哪一級。一般來說，確(que)實是(shi)(shi)信(xin)號過強(qiang)引起(qi)的(de)(de)削波(bo)，則(ze)(ze)應在前(qian)級設(she)(she)(she)(she)備(bei)(bei)上就將音(yin)量電(dian)平降下來，如屬設(she)(she)(she)(she)備(bei)(bei)故障(zhang)(如設(she)(she)(she)(she)備(bei)(bei)內(nei)的(de)(de)工作電(dian)源不正常或負反饋通路開路等(deng))則(ze)(ze)必(bi)須更(geng)換設(she)(she)(she)(she)備(bei)(bei)。

四、會議音響系統中聲音小的判斷與排除

在對各臺設(she)備(bei)的操(cao)作都符合規范的情(qing)況(kuang)下，聲(sheng)(sheng)音(yin)(yin)小(xiao)往(wang)往(wang)是連(lian)(lian)(lian)接(jie)線(xian)問(wen)題(ti)居多(duo)。如連(lian)(lian)(lian)接(jie)線(xian)短(duan)路，插(cha)頭、插(cha)座配合不好，連(lian)(lian)(lian)線(xian)虛(xu)焊等(deng)，在判(pan)定連(lian)(lian)(lian)接(jie)線(xian)沒有(you)問(wen)題(ti)后再懷疑設(she)備(bei)，檢查是那一臺設(she)備(bei)有(you)了(le)故障，然后再更換設(she)備(bei)。如聲(sheng)(sheng)音(yin)(yin)小(xiao)還伴隨聲(sheng)(sheng)場(chang)嚴重不均(jun)勻則應考(kao)慮揚聲(sheng)(sheng)器(qi)的相(xiang)位(wei)是否(fou)接(jie)錯。

五、會議音響系統中干擾噪聲

有時在一些地區的擴聲系統中可以聽到廣播電臺的聲音，或者其他干擾聲。例如來自雷達、高頻熱合機、電焊機等的(de)(de)(de)(de)干(gan)擾聲(sheng)，統(tong)(tong)(tong)稱為噪聲(sheng)。有時一套(tao)擴聲(sheng)系(xi)統(tong)(tong)(tong)安裝完，調(diao)(diao)(diao)試時可(ke)能聽到(dao)音(yin)(yin)(yin)(yin)箱(xiang)中發出(chu)間(jian)隙性(xing)雜(za)音(yin)(yin)(yin)(yin)，甚(shen)至出(chu)現廣(guang)播電(dian)(dian)(dian)(dian)(dian)(dian)臺的(de)(de)(de)(de)播音(yin)(yin)(yin)(yin)聲(sheng)，這(zhe)些聲(sheng)音(yin)(yin)(yin)(yin)往往是(shi)由于空間(jian)有較強的(de)(de)(de)(de)(被(bei)調(diao)(diao)(diao)制(zhi)的(de)(de)(de)(de))高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)波(bo)，擴聲(sheng)系(xi)統(tong)(tong)(tong)接(jie)收到(dao)這(zhe)些被(bei)調(diao)(diao)(diao)制(zhi)的(de)(de)(de)(de)高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)場后產生(sheng)高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)感應電(dian)(dian)(dian)(dian)(dian)(dian)動勢—高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)電(dian)(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)，然后這(zhe)個(ge)高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)電(dian)(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)通過擴聲(sheng)系(xi)統(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中的(de)(de)(de)(de)例如晶體二極(ji)管、晶體三極(ji)管、場效(xiao)應管、集成電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)等非線(xian)性(xing)元器件構成的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)對高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)電(dian)(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)進行解調(diao)(diao)(diao)，將寄生(sheng)于高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)信(xin)(xin)(xin)號(hao)中的(de)(de)(de)(de)音(yin)(yin)(yin)(yin)頻(pin)(pin)調(diao)(diao)(diao)制(zhi)信(xin)(xin)(xin)號(hao)解調(diao)(diao)(diao)出(chu)來(lai)(lai)，這(zhe)里高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)信(xin)(xin)(xin)號(hao)相當于被(bei)調(diao)(diao)(diao)制(zhi)的(de)(de)(de)(de)載波(bo)信(xin)(xin)(xin)號(hao)，而寄生(sheng)于這(zhe)些高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)信(xin)(xin)(xin)號(hao)中的(de)(de)(de)(de)音(yin)(yin)(yin)(yin)頻(pin)(pin)信(xin)(xin)(xin)號(hao)相當于調(diao)(diao)(diao)制(zhi)波(bo)信(xin)(xin)(xin)號(hao)，如果我(wo)們的(de)(de)(de)(de)擴聲(sheng)系(xi)統(tong)(tong)(tong)設計不是(shi)很到(dao)位(wei)，則可(ke)能將射頻(pin)(pin)無(wu)線(xian)電(dian)(dian)(dian)(dian)(dian)(dian)高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)干(gan)擾信(xin)(xin)(xin)號(hao)通過連接(jie)線(xian)較多地(di)接(jie)收進來(lai)(lai)，然后由于擴聲(sheng)設備電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de)(de)(de)非線(xian)性(xing)，將這(zhe)些高(gao)(gao)(gao)(gao)(gao)頻(pin)(pin)無(wu)線(xian)電(dian)(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)進行解調(diao)(diao)(diao)，從而產生(sheng)可(ke)感覺到(dao)的(de)(de)(de)(de)音(yin)(yin)(yin)(yin)頻(pin)(pin)干(gan)擾信(xin)(xin)(xin)號(hao)，最后在揚聲(sheng)器系(xi)統(tong)(tong)(tong)中播放出(chu)來(lai)(lai)。

解(jie)決這(zhe)個問題的(de)(de)(de)(de)首要(yao)方法(fa)是(shi)在系(xi)統設(she)計(ji)時注意(yi)采(cai)用平衡(heng)連(lian)接，到(dao)功率(lv)放大器輸(shu)(shu)入端(duan)為(wei)止的(de)(de)(de)(de)所有(you)(you)音頻(pin)(pin)(pin)線都(dou)應該采(cai)用屏蔽性能良(liang)好的(de)(de)(de)(de)音頻(pin)(pin)(pin)電纜，并且連(lian)接線的(de)(de)(de)(de)長度不要(yao)太長，接地良(liang)好。在這(zhe)些措施都(dou)到(dao)位的(de)(de)(de)(de)情況下，還有(you)(you)干擾信號(hao)出現時，則應該考(kao)(kao)慮加入射(she)頻(pin)(pin)(pin)濾(lv)波(bo)器，目前很多周邊設(she)備的(de)(de)(de)(de)信號(hao)輸(shu)(shu)入端(duan)加有(you)(you)射(she)頻(pin)(pin)(pin)濾(lv)波(bo)器電路(lu)，能對射(she)頻(pin)(pin)(pin)信號(hao)進行抑(yi)制，但是(shi)調音臺(tai)等設(she)備的(de)(de)(de)(de)輸(shu)(shu)入端(duan)沒有(you)(you)設(she)置射(she)頻(pin)(pin)(pin)濾(lv)波(bo)器電路(lu)。考(kao)(kao)慮到(dao)廣播調頻(pin)(pin)(pin)中波(bo)的(de)(de)(de)(de)最低(di)載波(bo)頻(pin)(pin)(pin)率(lv)是(shi)535kHz，所以(yi)(yi)建議射(she)頻(pin)(pin)(pin)低(di)通濾(lv)波(bo)器的(de)(de)(de)(de)-3dB頻(pin)(pin)(pin)率(lv)選(xuan)在400kHz，這(zhe)樣比音頻(pin)(pin)(pin)最高(gao)頻(pin)(pin)(pin)率(lv)20kHz高(gao)了20倍(bei)，不至于(yu)影響音頻(pin)(pin)(pin)信號(hao)的(de)(de)(de)(de)傳(chuan)輸(shu)(shu)，當然比40kHz頻(pin)(pin)(pin)率(lv)再低(di)一些也(ye)不是(shi)不可(ke)以(yi)(yi)，但是(shi)起(qi)碼要(yao)在200kHz以(yi)(yi)上。可(ke)以(yi)(yi)用RC構(gou)成阻容低(di)通濾(lv)波(bo)器，也(ye)可(ke)以(yi)(yi)用LC構(gou)成濾(lv)波(bo)器，將低(di)通濾(lv)波(bo)器接在調音臺(tai)的(de)(de)(de)(de)輸(shu)(shu)入端(duan)，尤其是(shi)小信號(hao)音源與調音臺(tai)相連(lian)接的(de)(de)(de)(de)輸(shu)(shu)入口(kou)。