【會議話(hua)筒】會議話(hua)筒怎么選 詳解會議室話(hua)筒的選擇與使用

會(hui)議(yi)室中對(dui)聲響(xiang)通常需(xu)求亮堂(tang)、明晰(xi)，響(xiang)度要適中。在(zai)安(an)置會(hui)場時(shi)，說話者不能到現場試音。因而，要想(xiang)在(zai)現場擴聲時(shi)到達亮堂(tang)、明晰(xi)的(de)聲響(xiang)作用(響(xiang)度正好合(he)適但(dan)不嘯叫的(de)需(xu)求)，話筒的(de)挑(tiao)選與擺放的(de)方法就有一定的(de)學識。

1、話筒的挑選

由于不(bu)一樣(yang)的話(hua)(hua)(hua)筒(tong)對不(bu)一樣(yang)的聲源有不(bu)一樣(yang)的作用，因而(er)在挑選話(hua)(hua)(hua)筒(tong)之前必(bi)須(xu)深(shen)入了(le)解話(hua)(hua)(hua)筒(tong)的技能特(te)(te)性(xing)、功(gong)能好壞(huai)以(yi)及適用場合。話(hua)(hua)(hua)筒(tong)選用時除了(le)要(yao)考慮(lv)(lv)話(hua)(hua)(hua)筒(tong)的靈敏度(du)、輸出(chu)阻抗與調音臺輸入阻抗的匹配等電聲指標外(wai)，在會議室內還需要(yao)考慮(lv)(lv)話(hua)(hua)(hua)筒(tong)的指向特(te)(te)性(xing)、頻響特(te)(te)性(xing)以(yi)及話(hua)(hua)(hua)筒(tong)的外(wai)形等。

就指(zhi)向(xiang)(xiang)性(xing)(xing)(xing)而言，超心(xin)形適(shi)(shi)宜(yi)較(jiao)(jiao)遠間(jian)(jian)隔拾音(yin)，心(xin)形適(shi)(shi)宜(yi)大(da)多數情況，無指(zhi)向(xiang)(xiang)性(xing)(xing)(xing)話(hua)筒則不適(shi)(shi)宜(yi)言語拾音(yin)，因(yin)為(wei)簡單會(hui)(hui)導致回聲。另外，在會(hui)(hui)議室內還要(yao)依據音(yin)箱的規劃，來挑選(xuan)指(zhi)向(xiang)(xiang)特(te)性(xing)(xing)(xing)適(shi)(shi)宜(yi)的話(hua)筒。集(ji)中式或半集(ji)中式規劃的擴(kuo)(kuo)聲系統，話(hua)筒的指(zhi)向(xiang)(xiang)特(te)性(xing)(xing)(xing)應(ying)(ying)(ying)為(wei)心(xin)形或超心(xin)形;渙散(san)式規劃的擴(kuo)(kuo)聲系統，通常(chang)應(ying)(ying)(ying)挑選(xuan)心(xin)形話(hua)筒，若是話(hua)筒距擴(kuo)(kuo)聲音(yin)箱較(jiao)(jiao)遠，而廳堂混響時間(jian)(jian)不是過長，亦可(ke)挑選(xuan)無方向(xiang)(xiang)性(xing)(xing)(xing)話(hua)筒;當聲源(yuan)非常(chang)接近話(hua)筒時，可(ke)運用技能指(zhi)標消除近講效應(ying)(ying)(ying)的近講心(xin)形話(hua)筒。

就話(hua)筒(tong)(tong)的(de)頻響(xiang)特(te)(te)性而(er)言，往往靜(jing)態技(ji)能目標稍(shao)低(di)而(er)瞬(shun)(shun)態特(te)(te)性好的(de)話(hua)筒(tong)(tong)，要(yao)比靜(jing)態技(ji)能目標稍(shao)高而(er)瞬(shun)(shun)態特(te)(te)性差(cha)的(de)話(hua)筒(tong)(tong)好一(yi)些(xie)。兩(liang)位，從(cong)低(di)頻到高頻頻響(xiang)特(te)(te)性均勻、滑(hua)潤的(de)話(hua)筒(tong)(tong)比某(mou)一(yi)頻段杰出(chu)的(de)話(hua)簡要(yao)好，由于杰出(chu)的(de)有些(xie)也(ye)會導(dao)致(zhi)嘯叫(jiao)。

此外，鈍重的(de)口聲往往由于(yu)話筒(tong)過近(jin)而被過火(huo)加劇。當然(ran)，可(ke)以用電子校(xiao)對(在傳(chuan)聲電路中(zhong))來抵償，這對于(yu)音頻太低的(de)口聲沒有(you)影響，但對于(yu)前后的(de)移動(dong)有(you)約束，發話人與話筒(tong)的(de)間隔必須堅持穩定(ding)，不(bu)然(ran)低頻成分會(hui)有(you)改變(bian)，而直達聲與混響聲(在音響狀況“活潑”的(de)聲場中(zhong))之間的(de)比率(lv)也會(hui)發生(sheng)改變(bian)。

在(zai)6000—9000Hz之間大量呈現(xian)峰值(zhi)的(de)(de)(de)話(hua)(hua)筒(tong)(tong)，會使帶咝咝音的(de)(de)(de)口音變得齒音更(geng)重。當然，也(ye)可用(yong)電(dian)子辦法校對，但要(yao)付出在(zai)峰頂帶來死點的(de)(de)(de)價(jia)值(zhi)。因(yin)而(er)，會議室通(tong)常沒有必要(yao)用(yong)高質量的(de)(de)(de)話(hua)(hua)筒(tong)(tong)，具有滑潤呼應的(de)(de)(de)話(hua)(hua)筒(tong)(tong)就可以了。就話(hua)(hua)筒(tong)(tong)的(de)(de)(de)內部(bu)構造(zao)類型而(er)言，通(tong)常會議室擴(kuo)聲(sheng)以往選(xuan)用(yong)動圈式話(hua)(hua)筒(tong)(tong)。這些(xie)年，隨著會議桌子的(de)(de)(de)加大、加寬，如今(jin)大都(dou)挑(tiao)選(xuan)電(dian)容式鵝頸(jing)話(hua)(hua)筒(tong)(tong)。這樣(yang)，在(zai)會議桌比較(jiao)寬時，不(bu)(bu)至于被說(shuo)話(hua)(hua)者推到(dao)桌邊而(er)拾取不(bu)(bu)到(dao)聲(sheng)響。別的(de)(de)(de)，電(dian)容話(hua)(hua)筒(tong)(tong)的(de)(de)(de)話(hua)(hua)筒(tong)(tong)頭比較(jiao)小，不(bu)(bu)至于遮住說(shuo)話(hua)(hua)者的(de)(de)(de)臉部(bu)也(ye)是(shi)被挑(tiao)選(xuan)的(de)(de)(de)緣由之一(yi)。

綜(zong)上所述，除特殊需求外，會(hui)議(yi)室(shi)通常引薦選用頻(pin)率響應(ying)寬，頻(pin)響傳(chuan)輸(shu)特性(xing)均勻、滑潤、失真度小(xiao)的電(dian)容(rong)式(shi)鵝頸心(xin)形話(hua)筒。

2、話筒的擺放

會議室(shi)的(de)(de)話(hua)(hua)筒(tong)(tong)(tong)(tong)擺(bai)放通常(chang)分(fen)為(wei)桌面(mian)擺(bai)放與(yu)話(hua)(hua)筒(tong)(tong)(tong)(tong)架擺(bai)放兩種。在(zai)桌面(mian)上擺(bai)放話(hua)(hua)筒(tong)(tong)(tong)(tong)時，要注意說話(hua)(hua)者嘴(zui)(zui)部(bu)(bu)與(yu)話(hua)(hua)筒(tong)(tong)(tong)(tong)中(zhong)間(jian)的(de)(de)夾角(jiao)和間(jian)隔，最好使話(hua)(hua)筒(tong)(tong)(tong)(tong)的(de)(de)中(zhong)間(jian)軸(zhou)線對準說話(hua)(hua)者的(de)(de)嘴(zui)(zui)部(bu)(bu)，這時話(hua)(hua)筒(tong)(tong)(tong)(tong)輸出的(de)(de)頻響特性(xing)最佳;嘴(zui)(zui)部(bu)(bu)違背(bei)中(zhong)間(jian)軸(zhou)線越(yue)遠，頻響特性(xing)越(yue)差(cha)，高音丟(diu)失越(yue)嚴峻，且(qie)話(hua)(hua)筒(tong)(tong)(tong)(tong)的(de)(de)輸出電壓也(ye)會削減。通常(chang)心形話(hua)(hua)筒(tong)(tong)(tong)(tong)，嘴(zui)(zui)部(bu)(bu)與(yu)中(zhong)間(jian)軸(zhou)線的(de)(de)夾角(jiao)在(zai)450規模以內是適宜的(de)(de)。

會(hui)議室說(shuo)話(hua)(hua)時，為了加強言(yan)語明晰(xi)度，話(hua)(hua)筒(tong)距(ju)嘴部以20—30cm為宜，太(tai)近，則(ze)易呈(cheng)現低頻噴口音(yin)，影(ying)響聲(sheng)響的明晰(xi)度，太(tai)遠，話(hua)(hua)筒(tong)又拾取過多的反射聲(sheng)與混(hun)響聲(sheng)，容(rong)易導致嘯叫(jiao)。此刻，若是調音(yin)臺(tai)推得(de)太(tai)小，則(ze)聲(sheng)響響度達(da)不到需(xu)求，聽眾聽不清說(shuo)話(hua)(hua)內容(rong)，推得(de)太(tai)大又容(rong)易嘯叫(jiao)。所(suo)以，擺放話(hua)(hua)筒(tong)時精確估量說(shuo)話(hua)(hua)者的說(shuo)話(hua)(hua)間隔至關(guan)重要。

當有多(duo)(duo)人說話，需(xu)擺(bai)放多(duo)(duo)個話筒時，應使話筒之間(jian)的(de)(de)間(jian)隔大于(yu)聲源與話筒間(jian)隔的(de)(de)3倍(即滿(man)意3：1準則)，以減小信(xin)號相加時發(fa)生的(de)(de)相位干涉現象。

當一個(ge)人說話(hua)(hua)(hua)，需(xu)要(yao)(yao)用兩(liang)(liang)(liang)個(ge)或(huo)(huo)多(duo)個(ge)話(hua)(hua)(hua)筒(tong)(tong)(tong)進行拾音時(例(li)如(ru)做陳述)，要(yao)(yao)將(jiang)兩(liang)(liang)(liang)個(ge)或(huo)(huo)多(duo)個(ge)話(hua)(hua)(hua)筒(tong)(tong)(tong)盡量接近(jin)，并堅(jian)持每個(ge)話(hua)(hua)(hua)筒(tong)(tong)(tong)到聲源(說話(hua)(hua)(hua)者嘴部)的(de)間隔盡量持平，避(bi)免(mian)信號相(xiang)(xiang)(xiang)加時發生相(xiang)(xiang)(xiang)位(wei)干涉現象(xiang)。此(ci)(ci)刻(ke)，格外(wai)(wai)要(yao)(yao)注意話(hua)(hua)(hua)筒(tong)(tong)(tong)相(xiang)(xiang)(xiang)位(wei)要(yao)(yao)共同(tong)。以(yi)兩(liang)(liang)(liang)支(zhi)話(hua)(hua)(hua)筒(tong)(tong)(tong)為例(li)，若是兩(liang)(liang)(liang)支(zhi)話(hua)(hua)(hua)筒(tong)(tong)(tong)拾音還(huan)沒有一支(zhi)話(hua)(hua)(hua)筒(tong)(tong)(tong)音量大，則闡(chan)明兩(liang)(liang)(liang)支(zhi)話(hua)(hua)(hua)筒(tong)(tong)(tong)反相(xiang)(xiang)(xiang)，此(ci)(ci)刻(ke)，需(xu)將(jiang)一支(zhi)話(hua)(hua)(hua)筒(tong)(tong)(tong)的(de)相(xiang)(xiang)(xiang)位(wei)進行調(diao)整(zheng)，通常(chang)來說，問題出在話(hua)(hua)(hua)筒(tong)(tong)(tong)線上，只要(yao)(yao)將(jiang)一支(zhi)話(hua)(hua)(hua)筒(tong)(tong)(tong)的(de)接線調(diao)整(zheng)過(guo)來即可。話(hua)(hua)(hua)筒(tong)(tong)(tong)架(jia)擺(bai)放時，由于許多(duo)話(hua)(hua)(hua)筒(tong)(tong)(tong)架(jia)是三角支(zhi)架(jia)，所以(yi)裝置上話(hua)(hua)(hua)筒(tong)(tong)(tong)后，要(yao)(yao)讓話(hua)(hua)(hua)筒(tong)(tong)(tong)的(de)重(zhong)心投(tou)影落在某一個(ge)支(zhi)腳上，另(ling)外(wai)(wai)，裝置話(hua)(hua)(hua)筒(tong)(tong)(tong)的(de)活動桿(gan)不要(yao)(yao)抽(chou)得太(tai)長，避(bi)免(mian)話(hua)(hua)(hua)筒(tong)(tong)(tong)重(zhong)心超出支(zhi)架(jia)規模以(yi)外(wai)(wai)而(er)傾倒。

3、話筒的試音

由于會議室的(de)特(te)殊性，大多(duo)數狀況(kuang)下不(bu)(bu)能讓說話(hua)者親(qin)臨會場試音(yin)(yin)(yin)(例(li)如領(ling)導(dao)說話(hua))，所以只需(xu)按正常人的(de)音(yin)(yin)(yin)量調(diao)好即可，盡(jin)量做(zuo)到讓說話(hua)者的(de)首句話(hua)就到達音(yin)(yin)(yin)量適(shi)中(聲響巨細適(shi)中又(you)(you)不(bu)(bu)嘯叫(jiao))，但又(you)(you)要留有(you)(you)滿(man)足的(de)調(diao)理(li)容量。但若(ruo)是有(you)(you)許多(duo)話(hua)筒(tong)時，調(diao)音(yin)(yin)(yin)員需(xu)要在調(diao)音(yin)(yin)(yin)臺和話(hua)筒(tong)之間進行重復的(de)調(diao)試，很費(fei)事且功(gong)率不(bu)(bu)高。

這(zhe)里有一個小(xiao)(xiao)竅(qiao)門，即(ji)是將(jiang)話(hua)(hua)筒擺好今(jin)后(hou)(hou)，將(jiang)一切(qie)話(hua)(hua)筒的(de)調音(yin)(yin)臺(tai)(tai)推子(zi)(zi)放在最(zui)低(di)，增益旋(xuan)紐調在最(zui)小(xiao)(xiao)處(chu)，然(ran)后(hou)(hou)將(jiang)功放調到(dao)往常運用(yong)的(de)恰當(dang)方位，將(jiang)調音(yin)(yin)臺(tai)(tai)主(zhu)輸出推至(zhi)0dB處(chu)，然(ran)后(hou)(hou)將(jiang)某一路(lu)(lu)話(hua)(hua)筒的(de)對(dui)應推子(zi)(zi)推至(zhi)該路(lu)(lu)最(zui)高電(dian)平處(chu)(通常調音(yin)(yin)臺(tai)(tai)為(wei)10～12dB)，再緩(huan)慢調理(li)調音(yin)(yin)臺(tai)(tai)上(shang)該路(lu)(lu)話(hua)(hua)筒的(de)增益旋(xuan)紐，并細(xi)心監聽聲(sheng)響(xiang)，直(zhi)到(dao)聽到(dao)有細(xi)微的(de)嘯叫(jiao)(jiao)聲(sheng)時，行將(jiang)旋(xuan)紐往回退3dB，然(ran)后(hou)(hou)再將(jiang)該路(lu)(lu)推子(zi)(zi)拉回到(dao)0dB處(chu)。這(zhe)樣，該路(lu)(lu)話(hua)(hua)筒就能既確保說話(hua)(hua)者有滿足的(de)音(yin)(yin)量(liang)響(xiang)度(du)體現，又不(bu)至(zhi)于導致嘯叫(jiao)(jiao)，當(dang)說話(hua)(hua)者聲(sheng)響(xiang)較小(xiao)(xiao)時，又有滿足的(de)裕量(liang)(13dB)可供調整。相同(tong)處(chu)置其他話(hua)(hua)筒即(ji)可。這(zhe)樣調整今(jin)后(hou)(hou)，一起翻開(kai)多支話(hua)(hua)筒也不(bu)會導致嘯叫(jiao)(jiao)。