當會(hui)議系統音響設(she)備故(gu)障時(shi),該如何(he)(he)是好(hao)?現在,小編就為大家簡單的介紹一(yi)下,會議系(xi)統音響(xiang)設(she)備在發生故(gu)障的時(shi)候(hou),該如何(he)(he)去判斷和排除。
一、會議系統音響無聲故障的判斷與排除
1、檢(jian)查所有(you)設備是否(fou)都已(yi)(yi)(yi)開啟,各(ge)設備的音(yin)量控制鈕是否(fou)都已(yi)(yi)(yi)調到合適位置,調音(yin)臺上(shang)各(ge)通(tong)道路徑開關是否(fou)已(yi)(yi)(yi)選通(tong),檢(jian)查各(ge)連(lian)(lian)接線是否(fou)已(yi)(yi)(yi)連(lian)(lian)接正(zheng)確、可(ke)靠。
2、如(ru)(ru)(ru)(ru)還(huan)無(wu)聲(sheng)則需(xu)逐級(ji)檢(jian)(jian)查(cha)(cha)(cha),可以從(cong)后向前逐級(ji)檢(jian)(jian)查(cha)(cha)(cha),也(ye)可從(cong)前向后逐級(ji)檢(jian)(jian)查(cha)(cha)(cha)。從(cong)前向后查(cha)(cha)(cha)時,首先用(yong)監(jian)聽耳機檢(jian)(jian)查(cha)(cha)(cha)信號是否已進人(ren)(ren)調音臺(tai),然后可以用(yong)電(dian)壓表、萬用(yong)表逐級(ji)檢(jian)(jian)查(cha)(cha)(cha),直(zhi)至查(cha)(cha)(cha)出(chu)無(wu)聲(sheng)的一(yi)(yi)級(ji)并判斷是設(she)(she)(she)備(bei)(bei)(bei)(bei)無(wu)輸(shu)出(chu),還(huan)是連線(xian)有(you)(you)問題。如(ru)(ru)(ru)(ru)確屬(shu)設(she)(she)(she)備(bei)(bei)(bei)(bei)故(gu)(gu)障(zhang),則應更換(huan)備(bei)(bei)(bei)(bei)用(yong)設(she)(she)(she)備(bei)(bei)(bei)(bei)以救急;如(ru)(ru)(ru)(ru)果(guo)屬(shu)于(yu)周(zhou)(zhou)邊(bian)設(she)(she)(she)備(bei)(bei)(bei)(bei)出(chu)現故(gu)(gu)障(zhang),在沒有(you)(you)備(bei)(bei)(bei)(bei)用(yong)設(she)(she)(she)備(bei)(bei)(bei)(bei)的情況下,可以直(zhi)接將出(chu)故(gu)(gu)障(zhang)的周(zhou)(zhou)邊(bian)設(she)(she)(she)備(bei)(bei)(bei)(bei)跳過(guo)。例如(ru)(ru)(ru)(ru)均(jun)衡(heng)器出(chu)現故(gu)(gu)障(zhang)了(le),則可以將輸(shu)人(ren)(ren)到(dao)(dao)均(jun)衡(heng)器的輸(shu)人(ren)(ren)線(xian)插頭拔出(chu)來加到(dao)(dao)后一(yi)(yi)級(ji)設(she)(she)(she)備(bei)(bei)(bei)(bei)的輸(shu)人(ren)(ren)插座(zuo);如(ru)(ru)(ru)(ru)果(guo)是調音臺(tai)的某一(yi)(yi)輸(shu)人(ren)(ren)通(tong)道(dao)出(chu)現故(gu)(gu)障(zhang),則可以換(huan)一(yi)(yi)路(lu)輸(shu)人(ren)(ren)通(tong)道(dao).直(zhi)到(dao)(dao)活動結束(shu)后再更換(huan)設(she)(she)(she)備(bei)(bei)(bei)(bei);如(ru)(ru)(ru)(ru)屬(shu)連接線(xian)有(you)(you)問題,則在急用(yong)時先換(huan)備(bei)(bei)(bei)(bei)用(yong)線(xian),然后有(you)(you)空時再修理(li)設(she)(she)(she)備(bei)(bei)(bei)(bei)和連接線(xian)。對于(yu)設(she)(she)(she)備(bei)(bei)(bei)(bei),如(ru)(ru)(ru)(ru)自己不熟悉設(she)(she)(she)備(bei)(bei)(bei)(bei)內部結構(gou)、原(yuan)理(li)時不要輕易動手修理(li),以免小故(gu)(gu)障(zhang)變(bian)成大故(gu)(gu)障(zhang)當用(yong)電(dian)容麥(mai)克風時,還(huan)應檢(jian)(jian)查(cha)(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)(heng)聲(sheng)往(wang)(wang)往(wang)(wang)是(shi)(shi)由(you)于接(jie)(jie)地(di)(di)(di)不(bu)(bu)良或(huo)不(bu)(bu)對(dui),系(xi)統(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)設備不(bu)(bu)在同(tong)一(yi)路電(dian)(dian)網上,地(di)(di)(di)電(dian)(dian)位嚴重相差引(yin)起的(de)(de)(de)(de)(de)(de)(de),而(er)連(lian)接(jie)(jie)線的(de)(de)(de)(de)(de)(de)(de)屏蔽層脫焊或(huo)屏蔽線接(jie)(jie)得不(bu)(bu)對(dui)而(er)形(xing)成地(di)(di)(di)電(dian)(dian)流回路,也(ye)會引(yin)起哼(heng)(heng)聲(sheng)大(da)。所以(yi)(yi)應著(zhu)重檢查這些(xie)方面,必要(yao)時(shi)(shi)應加(jia)隔(ge)(ge)離(li)(li)用音頻(pin)變(bian)(bian)壓器,以(yi)(yi)便把前后(hou)級設備間的(de)(de)(de)(de)(de)(de)(de)“地(di)(di)(di)”斷開,而(er)信號仍然暢(chang)通(tong)。尤其是(shi)(shi)在兩個系(xi)統(tong)(tong)(tong)之(zhi)間相連(lian)接(jie)(jie)時(shi)(shi),往(wang)(wang)往(wang)(wang)會由(you)于兩個系(xi)統(tong)(tong)(tong)不(bu)(bu)用同(tong)一(yi)電(dian)(dian)源而(er)引(yin)起兩個系(xi)統(tong)(tong)(tong)之(zhi)間的(de)(de)(de)(de)(de)(de)(de)地(di)(di)(di)電(dian)(dian)位不(bu)(bu)同(tong),有(you)時(shi)(shi)甚至非常嚴重,從(cong)而(er)產(chan)生明顯的(de)(de)(de)(de)(de)(de)(de)哼(heng)(heng)聲(sheng)。對(dui)這種原因(yin)引(yin)起的(de)(de)(de)(de)(de)(de)(de)非常容易判斷,只要(yao)將兩個系(xi)統(tong)(tong)(tong)之(zhi)間的(de)(de)(de)(de)(de)(de)(de)連(lian)接(jie)(jie)信號線插頭(tou)從(cong)一(yi)個系(xi)統(tong)(tong)(tong)拔掉,哼(heng)(heng)聲(sheng)馬(ma)上會消失(shi)。如果確認哼(heng)(heng)聲(sheng)是(shi)(shi)由(you)于兩個系(xi)統(tong)(tong)(tong)電(dian)(dian)源的(de)(de)(de)(de)(de)(de)(de)地(di)(di)(di)電(dian)(dian)位不(bu)(bu)同(tong)引(yin)起的(de)(de)(de)(de)(de)(de)(de),則可以(yi)(yi)采取(qu)將兩個系(xi)統(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)“地(di)(di)(di)”隔(ge)(ge)離(li)(li)的(de)(de)(de)(de)(de)(de)(de)方法(fa),通(tong)常用加(jia)隔(ge)(ge)離(li)(li)用音頻(pin)變(bian)(bian)壓器來達到(dao)目的(de)(de)(de)(de)(de)(de)(de)對(dui)隔(ge)(ge)離(li)(li)用音頻(pin)變(bian)(bian)壓器的(de)(de)(de)(de)(de)(de)(de)技(ji)術要(yao)求(qiu)是(shi)(shi):
①一、二(er)次(ci)繞組用同(tong)樣規格的導線(xian)繞制,圈(quan)數比為1:1;
②輸人(ren)阻抗和(he)輸出(chu)阻抗均為600Ω;
③諧波失真不大于10%;
④頻率響應(ying)在(zai)40Hz~16kHz范圍內優于士(shi)0.5dB;
⑤功(gong)率最(zui)好不小于100mW。
三、會議音響系統中削波失棄的判斷與排除
首先檢(jian)查各設(she)備上的(de)(de)(de)削(xue)(xue)(xue)波(bo)指示(shi)燈是(shi)否亮著(zhu),如(ru)(ru)并未發現削(xue)(xue)(xue)波(bo)指示(shi)燈連(lian)續亮,則(ze)可以(yi)選擇(ze)系統靠(kao)中(zhong)間的(de)(de)(de)一臺設(she)備把音(yin)量(liang)(liang)降(jiang)低幾(ji)個dB.以(yi)判斷是(shi)該設(she)備的(de)(de)(de)前(qian)面已有削(xue)(xue)(xue)波(bo)失真(zhen),還是(shi)在該設(she)備后面才產生的(de)(de)(de)削(xue)(xue)(xue)波(bo)失真(zhen)。如(ru)(ru)此(ci)經過(guo)幾(ji)次調節音(yin)量(liang)(liang)控制器,即可判斷削(xue)(xue)(xue)波(bo)來自哪一級。一般(ban)來說,確實是(shi)信號過(guo)強(qiang)引起的(de)(de)(de)削(xue)(xue)(xue)波(bo),則(ze)應在前(qian)級設(she)備上就(jiu)將音(yin)量(liang)(liang)電(dian)平降(jiang)下來,如(ru)(ru)屬設(she)備故障(zhang)(如(ru)(ru)設(she)備內(nei)的(de)(de)(de)工作電(dian)源不(bu)正常或負反(fan)饋通(tong)路開路等)則(ze)必須更換(huan)設(she)備。
四、會議音響系統中聲音小的判斷與排除
在對各臺設備(bei)的操作都符(fu)合(he)規范的情況(kuang)下(xia),聲音(yin)小往往是連(lian)接(jie)線(xian)問(wen)(wen)題(ti)居(ju)多。如連(lian)接(jie)線(xian)短路,插頭、插座(zuo)配合(he)不好,連(lian)線(xian)虛(xu)焊等(deng),在判定連(lian)接(jie)線(xian)沒有(you)問(wen)(wen)題(ti)后(hou)再懷疑設備(bei),檢查是那一臺設備(bei)有(you)了(le)故障(zhang),然(ran)后(hou)再更換設備(bei)。如聲音(yin)小還伴隨聲場嚴重不均勻則應考慮揚聲器(qi)的相位是否接(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(deng)的(de)(de)干(gan)(gan)擾聲(sheng),統(tong)(tong)稱(cheng)為噪聲(sheng)。有時一套擴聲(sheng)系統(tong)(tong)安裝(zhuang)完,調試時可(ke)(ke)能(neng)聽到(dao)(dao)音(yin)(yin)箱中(zhong)發出間隙性雜音(yin)(yin),甚至(zhi)出現廣(guang)播電(dian)(dian)(dian)(dian)臺的(de)(de)播音(yin)(yin)聲(sheng),這(zhe)些聲(sheng)音(yin)(yin)往往是(shi)由(you)于(yu)空(kong)間有較(jiao)強的(de)(de)(被調制的(de)(de))高(gao)(gao)(gao)頻(pin)(pin)(pin)電(dian)(dian)(dian)(dian)磁(ci)波,擴聲(sheng)系統(tong)(tong)接(jie)(jie)收(shou)到(dao)(dao)這(zhe)些被調制的(de)(de)高(gao)(gao)(gao)頻(pin)(pin)(pin)電(dian)(dian)(dian)(dian)磁(ci)場(chang)后(hou)產(chan)(chan)生高(gao)(gao)(gao)頻(pin)(pin)(pin)感(gan)應電(dian)(dian)(dian)(dian)動(dong)勢(shi)—高(gao)(gao)(gao)頻(pin)(pin)(pin)電(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao),然后(hou)這(zhe)個高(gao)(gao)(gao)頻(pin)(pin)(pin)電(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)通(tong)過擴聲(sheng)系統(tong)(tong)電(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)中(zhong)的(de)(de)例如(ru)晶體二極(ji)管(guan)(guan)、晶體三(san)極(ji)管(guan)(guan)、場(chang)效應管(guan)(guan)、集成電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)等(deng)非(fei)線(xian)性元(yuan)器(qi)件(jian)構成的(de)(de)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)對高(gao)(gao)(gao)頻(pin)(pin)(pin)電(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)進(jin)行(xing)解調,將寄(ji)(ji)生于(yu)高(gao)(gao)(gao)頻(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)中(zhong)的(de)(de)音(yin)(yin)頻(pin)(pin)(pin)調制信(xin)(xin)(xin)號(hao)解調出來,這(zhe)里高(gao)(gao)(gao)頻(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)相(xiang)當于(yu)被調制的(de)(de)載(zai)波信(xin)(xin)(xin)號(hao),而(er)寄(ji)(ji)生于(yu)這(zhe)些高(gao)(gao)(gao)頻(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)中(zhong)的(de)(de)音(yin)(yin)頻(pin)(pin)(pin)信(xin)(xin)(xin)號(hao)相(xiang)當于(yu)調制波信(xin)(xin)(xin)號(hao),如(ru)果我們的(de)(de)擴聲(sheng)系統(tong)(tong)設計不是(shi)很到(dao)(dao)位,則可(ke)(ke)能(neng)將射頻(pin)(pin)(pin)無線(xian)電(dian)(dian)(dian)(dian)高(gao)(gao)(gao)頻(pin)(pin)(pin)干(gan)(gan)擾信(xin)(xin)(xin)號(hao)通(tong)過連接(jie)(jie)線(xian)較(jiao)多地(di)接(jie)(jie)收(shou)進(jin)來,然后(hou)由(you)于(yu)擴聲(sheng)設備電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)的(de)(de)非(fei)線(xian)性,將這(zhe)些高(gao)(gao)(gao)頻(pin)(pin)(pin)無線(xian)電(dian)(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)進(jin)行(xing)解調,從而(er)產(chan)(chan)生可(ke)(ke)感(gan)覺到(dao)(dao)的(de)(de)音(yin)(yin)頻(pin)(pin)(pin)干(gan)(gan)擾信(xin)(xin)(xin)號(hao),最后(hou)在(zai)揚聲(sheng)器(qi)系統(tong)(tong)中(zhong)播放出來。
解決(jue)這個問題的(de)(de)(de)(de)(de)(de)首要(yao)方法是(shi)在系統設計時注意采(cai)用平衡連接,到(dao)功(gong)率(lv)(lv)放(fang)大(da)器(qi)(qi)(qi)輸入(ru)(ru)端(duan)為止的(de)(de)(de)(de)(de)(de)所有(you)音(yin)(yin)頻(pin)(pin)線都應該采(cai)用屏蔽性能良好(hao)的(de)(de)(de)(de)(de)(de)音(yin)(yin)頻(pin)(pin)電(dian)纜(lan),并(bing)且連接線的(de)(de)(de)(de)(de)(de)長(chang)度(du)不(bu)要(yao)太長(chang),接地(di)良好(hao)。在這些(xie)(xie)措(cuo)施都到(dao)位(wei)的(de)(de)(de)(de)(de)(de)情況下,還(huan)有(you)干(gan)擾信(xin)號出現時,則(ze)應該考慮加入(ru)(ru)射頻(pin)(pin)濾(lv)波(bo)器(qi)(qi)(qi),目前很多周邊設備的(de)(de)(de)(de)(de)(de)信(xin)號輸入(ru)(ru)端(duan)加有(you)射頻(pin)(pin)濾(lv)波(bo)器(qi)(qi)(qi)電(dian)路(lu),能對射頻(pin)(pin)信(xin)號進行抑制,但(dan)是(shi)調音(yin)(yin)臺(tai)(tai)等設備的(de)(de)(de)(de)(de)(de)輸入(ru)(ru)端(duan)沒有(you)設置射頻(pin)(pin)濾(lv)波(bo)器(qi)(qi)(qi)電(dian)路(lu)。考慮到(dao)廣播調頻(pin)(pin)中波(bo)的(de)(de)(de)(de)(de)(de)最低(di)(di)載波(bo)頻(pin)(pin)率(lv)(lv)是(shi)535kHz,所以(yi)建議射頻(pin)(pin)低(di)(di)通(tong)濾(lv)波(bo)器(qi)(qi)(qi)的(de)(de)(de)(de)(de)(de)-3dB頻(pin)(pin)率(lv)(lv)選在400kHz,這樣(yang)比(bi)音(yin)(yin)頻(pin)(pin)最高頻(pin)(pin)率(lv)(lv)20kHz高了20倍,不(bu)至于影響音(yin)(yin)頻(pin)(pin)信(xin)號的(de)(de)(de)(de)(de)(de)傳輸,當然比(bi)40kHz頻(pin)(pin)率(lv)(lv)再(zai)低(di)(di)一些(xie)(xie)也(ye)不(bu)是(shi)不(bu)可以(yi),但(dan)是(shi)起(qi)碼要(yao)在200kHz以(yi)上。可以(yi)用RC構成阻容(rong)低(di)(di)通(tong)濾(lv)波(bo)器(qi)(qi)(qi),也(ye)可以(yi)用LC構成濾(lv)波(bo)器(qi)(qi)(qi),將低(di)(di)通(tong)濾(lv)波(bo)器(qi)(qi)(qi)接在調音(yin)(yin)臺(tai)(tai)的(de)(de)(de)(de)(de)(de)輸入(ru)(ru)端(duan),尤其是(shi)小信(xin)號音(yin)(yin)源與調音(yin)(yin)臺(tai)(tai)相連接的(de)(de)(de)(de)(de)(de)輸入(ru)(ru)口。