雅马哈yamaha_pm-1000eSERVICE-MANUAL维修手册电器原理图

SECTION FIVE1HOW TO USEtions are heard as an overall muddy character,andTHE CONSOLEreversing the phase of one microphone may improve thesound by altering the frequencies at which cancellationoccurs.When time permits,each input may be examinedto hear whether reversing the phase will improve theoverall sound character of the mix.This should be doneafter the initial set up,during the sound check.Listen-ing is the only valid means to determine the best phasesetting,and meters are not likely to help.What soundsNOTE:The information presented in the followingbest is best,except when the program is being moni-section of the manual complements the basic featuretored with two or more channels and is being recordedcallouts in Section 1.In some cases,those callouts pro-in a format with fewer channels.vide sufficient information,so the feature has not beenincluded in this section.If,for example,a stereo live mix sounds good,but amonaural mix is being recorded,the monaural outputshould be examined to determine whether the reversal ofINPUT MODULEone or more channels'phase switches will improve themix.The stereo monitor can sound acceptable due toPHASE SWITCHacoustic delays that tend to correct out-of-phase signals,When two or more mics are receiving the same pro-whereas the same signals,when mixed together,cancelgram source (or one mic is receiving leakage from theto a greater degree.source intended for another mic)an out-of-phase con-dition may cause acoustic phasing cancellations that willOUTPUT ASSIGN SWITCHES PAN POTbe most noticeable in the low frequencies.To checkThe pan pot is designed so that when it is set a mid-inputs for correct phase,begin with all channels in therotation,it will feed the left buses(1&3)and the rightN mode.Assign mics 1 and 2 to the cue bus,placing thebuses (2 4)at maximum and equal level.This permitsmicrophones close together and near a sound sourcethe pan pot to be moved off center during a performancethat contains appreciable bass.Using Input Level,without risk of overloading the channel(s)to which thematch the level of the two microphones.Then,listeningsignal is moved.In stereo sound reinforcement situationsto the blend of the two inputs in the cue headphones,as the pan pot is rotated to the mid-point,there is a 3dBreverse the phase of mic 2 by moving its phase switchacoustic build up at the center of the audience,makingto R.If the bass increases,leave the switch in R modethe audience aware of the intended motion.This un-and if the bass decreases,return the switch to N.Thisusually effective method of panning is an exclusiveestablishes an in-phase condition between mics 1 and 2.Yamaha feature.Repeat the procedure for mics 1 and 3,1 and 4,and soforth until all inputs have been compared to mic 1.LineThe pan pot and output assign switches are operatedinputs may be checked in a similar fashion,listening fortogether to achieve precisely the desired placement ofa decrease or increase in the bass content of the programthe input source i