當會議系統(tong)音響設(she)備故障(zhang)(zhang)時(shi),該如何是(shi)好?現在,小編就為(wei)大(da)家簡單的介紹(shao)一下,會(hui)議系統(tong)音響設(she)備在發生(sheng)故障(zhang)(zhang)的時(shi)候,該如何去(qu)判(pan)斷和排除。
一、會議系統音響無聲故障的判斷與排除
1、檢查所有設(she)備是否(fou)(fou)都(dou)已(yi)開啟,各(ge)設(she)備的音量控制鈕是否(fou)(fou)都(dou)已(yi)調到合(he)適位置,調音臺上各(ge)通(tong)道路徑(jing)開關是否(fou)(fou)已(yi)選通(tong),檢查各(ge)連接(jie)線(xian)是否(fou)(fou)已(yi)連接(jie)正確、可靠(kao)。
2、如還無聲則需逐級檢(jian)查(cha)(cha),可(ke)(ke)以(yi)從后(hou)向前(qian)逐級檢(jian)查(cha)(cha),也可(ke)(ke)從前(qian)向后(hou)逐級檢(jian)查(cha)(cha)。從前(qian)向后(hou)查(cha)(cha)時,首先(xian)用(yong)(yong)監聽耳(er)機檢(jian)查(cha)(cha)信號是否已進人(ren)調音(yin)臺(tai),然后(hou)可(ke)(ke)以(yi)用(yong)(yong)電(dian)壓表、萬用(yong)(yong)表逐級檢(jian)查(cha)(cha),直(zhi)至查(cha)(cha)出(chu)(chu)無聲的一級并(bing)判斷(duan)是設(she)(she)備(bei)(bei)(bei)無輸(shu)出(chu)(chu),還是連(lian)(lian)線(xian)有(you)問題。如確屬(shu)(shu)(shu)設(she)(she)備(bei)(bei)(bei)故(gu)障(zhang),則應更換(huan)備(bei)(bei)(bei)用(yong)(yong)設(she)(she)備(bei)(bei)(bei)以(yi)救(jiu)急(ji);如果屬(shu)(shu)(shu)于(yu)周邊(bian)設(she)(she)備(bei)(bei)(bei)出(chu)(chu)現(xian)故(gu)障(zhang),在(zai)沒有(you)備(bei)(bei)(bei)用(yong)(yong)設(she)(she)備(bei)(bei)(bei)的情況(kuang)下(xia),可(ke)(ke)以(yi)直(zhi)接(jie)將(jiang)出(chu)(chu)故(gu)障(zhang)的周邊(bian)設(she)(she)備(bei)(bei)(bei)跳(tiao)過。例如均衡器(qi)出(chu)(chu)現(xian)故(gu)障(zhang)了,則可(ke)(ke)以(yi)將(jiang)輸(shu)人(ren)到(dao)均衡器(qi)的輸(shu)人(ren)線(xian)插頭(tou)拔出(chu)(chu)來(lai)加到(dao)后(hou)一級設(she)(she)備(bei)(bei)(bei)的輸(shu)人(ren)插座;如果是調音(yin)臺(tai)的某一輸(shu)人(ren)通道出(chu)(chu)現(xian)故(gu)障(zhang),則可(ke)(ke)以(yi)換(huan)一路輸(shu)人(ren)通道.直(zhi)到(dao)活動(dong)結束(shu)后(hou)再更換(huan)設(she)(she)備(bei)(bei)(bei);如屬(shu)(shu)(shu)連(lian)(lian)接(jie)線(xian)有(you)問題,則在(zai)急(ji)用(yong)(yong)時先(xian)換(huan)備(bei)(bei)(bei)用(yong)(yong)線(xian),然后(hou)有(you)空時再修理(li)設(she)(she)備(bei)(bei)(bei)和連(lian)(lian)接(jie)線(xian)。對(dui)于(yu)設(she)(she)備(bei)(bei)(bei),如自己不熟悉設(she)(she)備(bei)(bei)(bei)內部結構、原理(li)時不要輕易動(dong)手(shou)修理(li),以(yi)免(mian)小故(gu)障(zhang)變(bian)成大故(gu)障(zhang)當用(yong)(yong)電(dian)容麥克風時,還應檢(jian)查(cha)(cha)幻像電(dian)源是否加上。
二、會議音響系統中哼聲大的判斷與排除
哼(heng)聲(sheng)往(wang)往(wang)是(shi)由(you)于接地(di)(di)不良或(huo)不對(dui),系(xi)(xi)統的(de)(de)(de)(de)(de)設(she)備不在同一(yi)(yi)路電(dian)(dian)網(wang)上,地(di)(di)電(dian)(dian)位(wei)嚴重相差引(yin)(yin)(yin)起的(de)(de)(de)(de)(de),而(er)連(lian)接線(xian)的(de)(de)(de)(de)(de)屏蔽層脫焊或(huo)屏蔽線(xian)接得不對(dui)而(er)形(xing)成(cheng)地(di)(di)電(dian)(dian)流回路,也會引(yin)(yin)(yin)起哼(heng)聲(sheng)大。所以(yi)應著重檢(jian)查這些方(fang)面,必要時(shi)(shi)(shi)應加隔(ge)離用(yong)(yong)音(yin)頻(pin)變(bian)壓器(qi),以(yi)便把前(qian)后級設(she)備間的(de)(de)(de)(de)(de)“地(di)(di)”斷開,而(er)信(xin)號仍然暢(chang)通(tong)。尤(you)其是(shi)在兩(liang)個系(xi)(xi)統之間相連(lian)接時(shi)(shi)(shi),往(wang)往(wang)會由(you)于兩(liang)個系(xi)(xi)統不用(yong)(yong)同一(yi)(yi)電(dian)(dian)源(yuan)而(er)引(yin)(yin)(yin)起兩(liang)個系(xi)(xi)統之間的(de)(de)(de)(de)(de)地(di)(di)電(dian)(dian)位(wei)不同,有時(shi)(shi)(shi)甚(shen)至非常嚴重,從而(er)產生明顯的(de)(de)(de)(de)(de)哼(heng)聲(sheng)。對(dui)這種原因引(yin)(yin)(yin)起的(de)(de)(de)(de)(de)非常容易(yi)判斷,只要將兩(liang)個系(xi)(xi)統之間的(de)(de)(de)(de)(de)連(lian)接信(xin)號線(xian)插(cha)頭從一(yi)(yi)個系(xi)(xi)統拔掉,哼(heng)聲(sheng)馬上會消失。如果確認哼(heng)聲(sheng)是(shi)由(you)于兩(liang)個系(xi)(xi)統電(dian)(dian)源(yuan)的(de)(de)(de)(de)(de)地(di)(di)電(dian)(dian)位(wei)不同引(yin)(yin)(yin)起的(de)(de)(de)(de)(de),則可(ke)以(yi)采取將兩(liang)個系(xi)(xi)統的(de)(de)(de)(de)(de)“地(di)(di)”隔(ge)離的(de)(de)(de)(de)(de)方(fang)法,通(tong)常用(yong)(yong)加隔(ge)離用(yong)(yong)音(yin)頻(pin)變(bian)壓器(qi)來(lai)達到目的(de)(de)(de)(de)(de)對(dui)隔(ge)離用(yong)(yong)音(yin)頻(pin)變(bian)壓器(qi)的(de)(de)(de)(de)(de)技術要求是(shi):
①一(yi)、二次繞組用同樣(yang)規格的導線繞制,圈數比為1:1;
②輸人阻(zu)抗和(he)輸出阻(zu)抗均為600Ω;
③諧波(bo)失(shi)真(zhen)不大于10%;
④頻率響應在(zai)40Hz~16kHz范圍內優于士0.5dB;
⑤功(gong)率(lv)最好(hao)不小于(yu)100mW。
三、會議音響系統中削波失棄的判斷與排除
首先(xian)檢查各設(she)(she)(she)備(bei)(bei)上的削(xue)波(bo)指示燈(deng)是(shi)否(fou)亮著,如并未發現削(xue)波(bo)指示燈(deng)連續亮,則可以選擇系(xi)統靠(kao)中間的一(yi)(yi)臺設(she)(she)(she)備(bei)(bei)把音量降低(di)幾個dB.以判斷(duan)是(shi)該設(she)(she)(she)備(bei)(bei)的前面已有削(xue)波(bo)失真(zhen),還是(shi)在該設(she)(she)(she)備(bei)(bei)后面才產生的削(xue)波(bo)失真(zhen)。如此經過(guo)幾次調節音量控制器,即可判斷(duan)削(xue)波(bo)來自哪一(yi)(yi)級(ji)(ji)。一(yi)(yi)般來說,確實是(shi)信(xin)號過(guo)強(qiang)引起(qi)的削(xue)波(bo),則應在前級(ji)(ji)設(she)(she)(she)備(bei)(bei)上就(jiu)將音量電平降下來,如屬(shu)設(she)(she)(she)備(bei)(bei)故(gu)障(如設(she)(she)(she)備(bei)(bei)內的工作電源(yuan)不正常或(huo)負反饋(kui)通路(lu)開(kai)路(lu)等)則必須更換(huan)設(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(dui)各(ge)臺(tai)設(she)(she)備的操(cao)作都符(fu)合(he)規范的情況下,聲(sheng)音(yin)小往往是連(lian)接(jie)(jie)線(xian)問(wen)題居(ju)多(duo)。如(ru)連(lian)接(jie)(jie)線(xian)短路,插頭、插座配合(he)不好(hao),連(lian)線(xian)虛(xu)焊等(deng),在判定連(lian)接(jie)(jie)線(xian)沒有(you)問(wen)題后再(zai)懷疑(yi)設(she)(she)備,檢(jian)查是那一臺(tai)設(she)(she)備有(you)了(le)故障,然后再(zai)更換(huan)設(she)(she)備。如(ru)聲(sheng)音(yin)小還伴隨聲(sheng)場嚴重不均勻則(ze)應考慮揚聲(sheng)器(qi)的相位是否接(jie)(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)干(gan)擾(rao)聲(sheng)(sheng)(sheng),統(tong)稱為(wei)噪聲(sheng)(sheng)(sheng)。有時(shi)一套擴(kuo)聲(sheng)(sheng)(sheng)系統(tong)安裝完(wan),調試時(shi)可(ke)能聽到音(yin)箱中發出間(jian)隙性(xing)雜音(yin),甚(shen)至(zhi)出現(xian)廣播電(dian)(dian)(dian)(dian)(dian)臺的(de)(de)(de)播音(yin)聲(sheng)(sheng)(sheng),這(zhe)些(xie)(xie)聲(sheng)(sheng)(sheng)音(yin)往(wang)往(wang)是由于(yu)空間(jian)有較強的(de)(de)(de)(被(bei)調制的(de)(de)(de))高頻(pin)(pin)(pin)(pin)電(dian)(dian)(dian)(dian)(dian)磁波(bo),擴(kuo)聲(sheng)(sheng)(sheng)系統(tong)接收到這(zhe)些(xie)(xie)被(bei)調制的(de)(de)(de)高頻(pin)(pin)(pin)(pin)電(dian)(dian)(dian)(dian)(dian)磁場后產生(sheng)高頻(pin)(pin)(pin)(pin)感應電(dian)(dian)(dian)(dian)(dian)動勢—高頻(pin)(pin)(pin)(pin)電(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)(hao),然(ran)(ran)后這(zhe)個高頻(pin)(pin)(pin)(pin)電(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)(hao)通過擴(kuo)聲(sheng)(sheng)(sheng)系統(tong)電(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)路中的(de)(de)(de)例如晶(jing)體二極管、晶(jing)體三極管、場效應管、集成電(dian)(dian)(dian)(dian)(dian)路等非線(xian)性(xing)元器(qi)件構成的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)路對高頻(pin)(pin)(pin)(pin)電(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)(hao)進行解(jie)調,將(jiang)寄(ji)生(sheng)于(yu)高頻(pin)(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)(hao)中的(de)(de)(de)音(yin)頻(pin)(pin)(pin)(pin)調制信(xin)(xin)(xin)號(hao)(hao)解(jie)調出來(lai),這(zhe)里高頻(pin)(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)(hao)相當于(yu)被(bei)調制的(de)(de)(de)載波(bo)信(xin)(xin)(xin)號(hao)(hao),而(er)寄(ji)生(sheng)于(yu)這(zhe)些(xie)(xie)高頻(pin)(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)(hao)中的(de)(de)(de)音(yin)頻(pin)(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)(hao)相當于(yu)調制波(bo)信(xin)(xin)(xin)號(hao)(hao),如果(guo)我們的(de)(de)(de)擴(kuo)聲(sheng)(sheng)(sheng)系統(tong)設(she)計不是很到位,則(ze)可(ke)能將(jiang)射頻(pin)(pin)(pin)(pin)無(wu)線(xian)電(dian)(dian)(dian)(dian)(dian)高頻(pin)(pin)(pin)(pin)干(gan)擾(rao)信(xin)(xin)(xin)號(hao)(hao)通過連接線(xian)較多地(di)接收進來(lai),然(ran)(ran)后由于(yu)擴(kuo)聲(sheng)(sheng)(sheng)設(she)備電(dian)(dian)(dian)(dian)(dian)路的(de)(de)(de)非線(xian)性(xing),將(jiang)這(zhe)些(xie)(xie)高頻(pin)(pin)(pin)(pin)無(wu)線(xian)電(dian)(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)(hao)進行解(jie)調,從而(er)產生(sheng)可(ke)感覺到的(de)(de)(de)音(yin)頻(pin)(pin)(pin)(pin)干(gan)擾(rao)信(xin)(xin)(xin)號(hao)(hao),最(zui)后在揚聲(sheng)(sheng)(sheng)器(qi)系統(tong)中播放出來(lai)。
解(jie)決這(zhe)個問題的(de)首要方(fang)法是(shi)在系(xi)統設(she)(she)計時注意采(cai)用平衡連接,到(dao)功率(lv)放大(da)器(qi)輸(shu)(shu)(shu)入(ru)(ru)端(duan)為止的(de)所有(you)音(yin)(yin)(yin)(yin)頻(pin)(pin)(pin)線(xian)都應該采(cai)用屏蔽性能(neng)良好(hao)的(de)音(yin)(yin)(yin)(yin)頻(pin)(pin)(pin)電纜,并且(qie)連接線(xian)的(de)長(chang)度不(bu)(bu)要太長(chang),接地(di)良好(hao)。在這(zhe)些措施(shi)都到(dao)位(wei)的(de)情況下,還有(you)干(gan)擾信(xin)(xin)(xin)(xin)號出現時,則(ze)應該考(kao)慮加入(ru)(ru)射頻(pin)(pin)(pin)濾(lv)(lv)(lv)波(bo)器(qi),目前很多周邊設(she)(she)備(bei)的(de)信(xin)(xin)(xin)(xin)號輸(shu)(shu)(shu)入(ru)(ru)端(duan)加有(you)射頻(pin)(pin)(pin)濾(lv)(lv)(lv)波(bo)器(qi)電路(lu),能(neng)對射頻(pin)(pin)(pin)信(xin)(xin)(xin)(xin)號進(jin)行抑(yi)制(zhi),但是(shi)調音(yin)(yin)(yin)(yin)臺(tai)等設(she)(she)備(bei)的(de)輸(shu)(shu)(shu)入(ru)(ru)端(duan)沒有(you)設(she)(she)置射頻(pin)(pin)(pin)濾(lv)(lv)(lv)波(bo)器(qi)電路(lu)。考(kao)慮到(dao)廣播調頻(pin)(pin)(pin)中波(bo)的(de)最低(di)(di)載(zai)波(bo)頻(pin)(pin)(pin)率(lv)是(shi)535kHz,所以(yi)建議射頻(pin)(pin)(pin)低(di)(di)通濾(lv)(lv)(lv)波(bo)器(qi)的(de)-3dB頻(pin)(pin)(pin)率(lv)選在400kHz,這(zhe)樣比(bi)音(yin)(yin)(yin)(yin)頻(pin)(pin)(pin)最高(gao)(gao)頻(pin)(pin)(pin)率(lv)20kHz高(gao)(gao)了(le)20倍,不(bu)(bu)至(zhi)于(yu)影響音(yin)(yin)(yin)(yin)頻(pin)(pin)(pin)信(xin)(xin)(xin)(xin)號的(de)傳輸(shu)(shu)(shu),當然比(bi)40kHz頻(pin)(pin)(pin)率(lv)再低(di)(di)一些也不(bu)(bu)是(shi)不(bu)(bu)可(ke)以(yi),但是(shi)起碼要在200kHz以(yi)上。可(ke)以(yi)用RC構成阻容低(di)(di)通濾(lv)(lv)(lv)波(bo)器(qi),也可(ke)以(yi)用LC構成濾(lv)(lv)(lv)波(bo)器(qi),將(jiang)低(di)(di)通濾(lv)(lv)(lv)波(bo)器(qi)接在調音(yin)(yin)(yin)(yin)臺(tai)的(de)輸(shu)(shu)(shu)入(ru)(ru)端(duan),尤其是(shi)小信(xin)(xin)(xin)(xin)號音(yin)(yin)(yin)(yin)源與調音(yin)(yin)(yin)(yin)臺(tai)相連接的(de)輸(shu)(shu)(shu)入(ru)(ru)口。