【傳聲(sheng)(sheng)器】專業麥(mai)克風(feng)的要求 使用傳聲(sheng)(sheng)器的注意事(shi)項

對專業麥克風的要求

高保真(zhen)和專業用傳聲器(qi)的(de)失真(zhen)度要小(xiao)于0.3%，寬頻響范(fan)圍，良(liang)(liang)好的(de)信(xin)噪比(bi)性能(neng)(neng)，良(liang)(liang)好的(de)聲電轉換能(neng)(neng)力，即有較高的(de)靈(ling)敏度。

傳聲器使用要點

（1）使用傳聲器之前，應(ying)先(xian)了(le)解傳(chuan)聲器(qi)的類型和(he)特性，往(wang)(wang)往(wang)(wang)靜(jing)態技術指(zhi)標稍低而瞬(shun)態特性好的傳(chuan)聲器(qi)，要比(bi)靜(jing)態指(zhi)標較(jiao)(jiao)高而瞬(shun)態特性較(jiao)(jiao)差的傳(chuan)聲器(qi)更好一些。電(dian)容式傳(chuan)聲器(qi)還應(ying)注意需加供(gong)電(dian)電(dian)源。

（2）傳聲(sheng)器位(wei)置附近不應有大的(de)反(fan)射面，如墻壁(bi)等，以避免強烈的(de)反(fan)射聲(sheng)引起聲(sheng)音(yin)相(xiang)位(wei)干(gan)涉而(er)破壞聲(sheng)音(yin)的(de)自然度。傳聲(sheng)器與音(yin)箱之間的(de)布位(wei)也十分重要(yao)(yao)，一般要(yao)(yao)求將傳聲(sheng)器安(an)放在音(yin)箱的(de)后(hou)面，避開音(yin)箱輻射方向。

（3）傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)的(de)插接件要牢固可靠。作為(wei)(wei)傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)插接件的(de)卡(ka)儂或大二芯插頭、插座(zuo)與(yu)(yu)傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)線(xian)(xian)焊接要求很規范(fan)。傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)必(bi)須(xu)(xu)使用(yong)優質屏(ping)(ping)(ping)蔽(bi)(bi)電纜傳送信(xin)號(hao)。由于傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)輸(shu)出信(xin)號(hao)很微弱，所以(yi)一旦竄入干擾(rao)信(xin)號(hao)就會產生雜(za)音(yin)，為(wei)(wei)此(ci)必(bi)須(xu)(xu)選用(yong)金屬屏(ping)(ping)(ping)蔽(bi)(bi)線(xian)(xian)傳輸(shu)信(xin)號(hao)，并(bing)應(ying)將屏(ping)(ping)(ping)蔽(bi)(bi)線(xian)(xian)的(de)一端(duan)與(yu)(yu)傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)的(de)外(wai)殼(ke)良好(hao)連接，另一端(duan)接音(yin)響設備的(de)外(wai)殼(ke)。屏(ping)(ping)(ping)蔽(bi)(bi)線(xian)(xian)的(de)長度也(ye)應(ying)盡量短。因(yin)為(wei)(wei)傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)線(xian)(xian)越(yue)長，分布電容越(yue)大，這不僅容易引起干擾(rao)信(xin)號(hao)，而且會引起人聲(sheng)(sheng)(sheng)(sheng)信(xin)號(hao)（特別(bie)是高音(yin)）的(de)損耗(hao)。一般說來(lai)(lai)，不平衡連接（單芯屏(ping)(ping)(ping)蔽(bi)(bi)線(xian)(xian)）時，傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)連線(xian)(xian)的(de)長度不宜超過10m，若(ruo)必(bi)須(xu)(xu)加(jia)長連接線(xian)(xian)，則應(ying)采用(yong)平衡接法（即用(yong)雙芯屏(ping)(ping)(ping)蔽(bi)(bi)線(xian)(xian)），以(yi)減(jian)少(shao)外(wai)來(lai)(lai)干擾(rao)。

（4）聲(sheng)(sheng)(sheng)(sheng)源與(yu)傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)的距(ju)離要(yao)適當。當演唱抒情歌曲時(shi)，演員常常將傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)靠(kao)近(jin)(jin)嘴邊，以充分(fen)利(li)用近(jin)(jin)講(jiang)效應，提(ti)升低音。近(jin)(jin)講(jiang)傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)與(yu)嘴部(bu)的距(ju)離可(ke)在1～20cm。作演講(jiang)時(shi)，為提(ti)高語言清晰度，傳聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)離嘴部(bu)宜(yi)在20～30cm，甚至還要(yao)專(zhuan)門切除些低頻效果(guo)。

（5）由于演唱或(huo)演講大(da)多(duo)使用單指向(xiang)(xiang)性(xing)(xing)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)，此時應(ying)注(zhu)意(yi)嘴(zui)(zui)部與(yu)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)中(zhong)(zhong)心(xin)(xin)軸線(xian)之間的夾角(jiao)大(da)小會影響拾取聲(sheng)(sheng)(sheng)(sheng)音信號(hao)的頻(pin)率特性(xing)(xing)。演唱時，嘴(zui)(zui)部對準傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)中(zhong)(zhong)心(xin)(xin)軸線(xian)夾角(jiao)為0°，傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)輸出(chu)的頻(pin)響特性(xing)(xing)最佳(jia)；嘴(zui)(zui)部偏離中(zhong)(zhong)心(xin)(xin)軸線(xian)越遠(yuan)，頻(pin)率特性(xing)(xing)變差，高音損(sun)失越嚴重(zhong)，且傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)輸出(chu)電壓也(ye)會減少(shao)。一(yi)般心(xin)(xin)形傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)，嘴(zui)(zui)部與(yu)中(zhong)(zhong)心(xin)(xin)軸線(xian)的夾角(jiao)宜保持在45°范圍內(nei)(nei)，對強(qiang)指向(xiang)(xiang)性(xing)(xing)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)則應(ying)保持在30°之內(nei)(nei)。

（6）良好的(de)(de)減(jian)(jian)振裝(zhuang)置。拾音單元固定在套架上，高(gao)檔(dang)傳(chuan)聲器(qi)有(you)減(jian)(jian)振裝(zhuang)置，防止傳(chuan)聲器(qi)因(yin)(yin)振動而產生振動噪(zao)聲或(huo)因(yin)(yin)傳(chuan)聲器(qi)意(yi)外掉在地(di)上或(huo)因(yin)(yin)磕(ke)碰產生強大的(de)(de)聲沖擊(ji)，損壞功(gong)放或(huo)音箱的(de)(de)高(gao)音單元。常用(yong)的(de)(de)減(jian)(jian)振裝(zhuang)置有(you)橡(xiang)膠減(jian)(jian)振支架、橡(xiang)膠傳(chuan)聲器(qi)夾(jia)子、橡(xiang)膠傳(chuan)聲器(qi)夾(jia)子墊、彈簧傳(chuan)聲器(qi)夾(jia)子．使用(yong)手(shou)持傳(chuan)聲器(qi)時，不要握住傳(chuan)聲器(qi)網罩，以(yi)免堵塞后(hou)面進(jin)氣孔，造成失(shi)真(zhen)，影響效果。使用(yong)無線傳(chuan)聲器(qi)時，其(qi)載(zai)頻應(ying)避開(kai)當地(di)調(diao)頻廣播或(huo)無線電話通信的(de)(de)頻率，以(yi)免相互(hu)串擾。

（7）抗干(gan)擾性能要(yao)好(hao)。聲(sheng)場中不可避免地(di)存(cun)在著某種磁(ci)場和電(dian)場，如空調、電(dian)源線和人體的(de)(de)靜(jing)電(dian)感(gan)應(ying)等。作為(wei)傳聲(sheng)器的(de)(de)拾音(yin)(yin)單元，很(hen)小的(de)(de)雜(za)聲(sheng)干(gan)擾經過調音(yin)(yin)臺和功率放大(da)(da)器放大(da)(da)后(hou)，送入揚聲(sheng)器就會(hui)形成很(hen)強(qiang)的(de)(de)雜(za)音(yin)(yin)，損(sun)害聲(sheng)音(yin)(yin)的(de)(de)質量(liang)，所以要(yao)求(qiu)傳聲(sheng)器結構、外殼要(yao)有良好(hao)的(de)(de)屏(ping)(ping)蔽作用(yong)，要(yao)求(qiu)全金(jin)屬(shu)結構，防磁(ci)性良好(hao)，要(yao)用(yong)良好(hao)的(de)(de)屏(ping)(ping)蔽傳聲(sheng)器導線。

（8）在使用(yong)多(duo)個傳聲(sheng)(sheng)器進(jin)行(xing)(xing)拾(shi)音(yin)時(shi)(shi)，首先(xian)應(ying)使各傳聲(sheng)(sheng)器的相位一(yi)致(zhi)；對(dui)一(yi)個聲(sheng)(sheng)源(yuan)如(ru)(ru)需用(yong)2支(zhi)或(huo)多(duo)個傳聲(sheng)(sheng)器進(jin)行(xing)(xing)單聲(sheng)(sheng)道拾(shi)音(yin)（如(ru)(ru)會議拾(shi)音(yin)）時(shi)(shi)就(jiu)將傳聲(sheng)(sheng)器盡量靠近(jin)，或(huo)保(bao)持每(mei)個傳聲(sheng)(sheng)器與聲(sheng)(sheng)源(yuan)的距(ju)離(li)(li)相等，以(yi)免(mian)相加(jia)時(shi)(shi)產生(sheng)相位干涉現(xian)象(xiang)；對(dui)2支(zhi)以(yi)上聲(sheng)(sheng)源(yuan)如(ru)(ru)需用(yong)2支(zhi)以(yi)上傳聲(sheng)(sheng)器拾(shi)音(yin)時(shi)(shi)，應(ying)使每(mei)個傳聲(sheng)(sheng)器之間的距(ju)離(li)(li)大于聲(sheng)(sheng)源(yuan)與傳聲(sheng)(sheng)器間距(ju)離(li)(li)的3倍（即(ji)滿足3:1規則），以(yi)減小(xiao)信號相加(jia)時(shi)(shi)產生(sheng)相位干涉現(xian)象(xiang)。

（9）要(yao)注意防(fang)風(feng)、防(fang)振、防(fang)潮(chao)。露天、室(shi)外(wai)演出(chu)要(yao)防(fang)風(feng)，避(bi)免風(feng)吹(chui)金屬網產生呼嘯聲(sheng)；空氣(qi)中的(de)灰(hui)塵(chen)進入傳聲(sheng)器(qi)，影(ying)響磁隙的(de)清(qing)潔(jie)度，會造成失真(zhen)；近(jin)講(jiang)傳聲(sheng)器(qi)，口形與傳聲(sheng)器(qi)很(hen)近(jin)，口中的(de)濕氣(qi)損害傳聲(sheng)器(qi)的(de)膜(mo)片(pian)，要(yao)使用防(fang)塵(chen)防(fang)潮(chao)罩。

傳聲(sheng)器(qi)(qi)的結構比較精密，強烈的振(zhen)動不僅會(hui)使傳聲(sheng)器(qi)(qi)的輸(shu)出(chu)太大，使擴聲(sheng)系統嚴重(zhong)過載，而且還容(rong)(rong)易損壞其機(ji)械結構，使磁鐵退(tui)磁、降低靈敏度，使音圈與磁路相碰等，所以(yi)要注(zhu)意(yi)防振(zhen)。尤其是電(dian)(dian)(dian)容(rong)(rong)傳聲(sheng)器(qi)(qi)，電(dian)(dian)(dian)容(rong)(rong)傳聲(sheng)器(qi)(qi)應(ying)先(xian)關閉電(dian)(dian)(dian)源(yuan)后再(zai)移動為好。此外(wai)，注(zhu)意(yi)不宜用吹氣或(huo)用手敲打傳聲(sheng)器(qi)(qi)的方法來試(shi)音。在傳聲(sheng)器(qi)(qi)的保管中，應(ying)注(zhu)意(yi)防潮，保持清潔衛生。

（10）傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)的相(xiang)(xiang)(xiang)(xiang)位。如果(guo)一部調音臺同(tong)時有(you)多(duo)只傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)輸入(ru)，若有(you)2支(zhi)(zhi)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)相(xiang)(xiang)(xiang)(xiang)位相(xiang)(xiang)(xiang)(xiang)反，當(dang)2支(zhi)(zhi)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)信號(hao)送(song)入(ru)調音臺混(hun)合電路中，則信號(hao)會相(xiang)(xiang)(xiang)(xiang)互抵消，其聲(sheng)(sheng)(sheng)(sheng)(sheng)音反而會減小，需進(jin)行(xing)調整。因此，使用(yong)多(duo)個(ge)(ge)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)時，尤(you)其是各種不同(tong)型號(hao)的傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)同(tong)時混(hun)合使用(yong)時，傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)的相(xiang)(xiang)(xiang)(xiang)位要一致。相(xiang)(xiang)(xiang)(xiang)位鑒別可用(yong)下述方法進(jin)行(xing)。先(xian)將所用(yong)的2支(zhi)(zhi)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)放在一起，同(tong)時接(jie)收一個(ge)(ge)聲(sheng)(sheng)(sheng)(sheng)(sheng)源，送(song)出聲(sheng)(sheng)(sheng)(sheng)(sheng)響增大，說(shuo)明2支(zhi)(zhi)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)同(tong)相(xiang)(xiang)(xiang)(xiang)，如果(guo)送(song)出聲(sheng)(sheng)(sheng)(sheng)(sheng)響減小，并(bing)出現(xian)失真，說(shuo)明傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)反相(xiang)(xiang)(xiang)(xiang)。將其中1支(zhi)(zhi)傳(chuan)(chuan)聲(sheng)(sheng)(sheng)(sheng)(sheng)器(qi)(qi)(qi)接(jie)線調整過來(lai)，以達(da)到同(tong)相(xiang)(xiang)(xiang)(xiang)聲(sheng)(sheng)(sheng)(sheng)(sheng)。