Weak current College】 【professional audio systems (2) --- Power By】 【China power house network.

<br> <br> Third, the sound system to operation breakdown: <br> "Science and technology people oriented", is not bad, then good, then advanced equipment to people to action is, of course, the people will make mistakes ., resulting in the sound system in a number of operational failure is inevitable. We can only strive to learn and strengthen their own, temper their, accumulation of experience, try to avoid human errors caused by the fault. <br> <br> Signal .connection problems: <br> On the audio system connection I have been told earlier in the article, then refine it here: <br> Sources playback device and connection: all kinds of sound mixer CD, DVD, MD, deck, with its accompanying .wire connection with mixer, generally in high ports. <br> 2 dynamic microphone and cable, capacitor microphone, XLR Plug in general low resistance port. But wireless microphone signal is amplified through the receiver, you need to experiment to know into which of the .port. <br> 3. principle the band equipment output signals to plug into high port, but if the line is long, interference, can plug in low resistance signal port. <br> Other sources of signals are can do the following experiment to .see what kind of port input is appropriate. If the input to the mixer's line has a problem, it's very troublesome, most afraid of is the line is not bad, but no sound, accompanied by intermittent noise, so the signal line we sound best .yourself and connect, do have bottom before maximum avoid failure.) <br> (Ii), device control problems: <br> Audio equipment is very wide, for our sound engineer, to put it on each audio equipment are adjusting well, we .say that the fault of human action mainly occurs in the performance period, such as: the silent, staccato, transfusion, noise, etc., the following we will explain them vulnerable people-operation breakdown of common audio device: <br> (A .), <br> Mixing consoles: we usually put the mixer analogy into a sound system of the heart or brain, thus producing a mixer is also for operation breakdown of audio equipment, sound mixer for operation breakdown usually manifested as: silent and sound is .very small, distorted, sound suddenly big or small, serious and transfusion, visible noise, etc. <br> <br> 1 mixer channel level attenuation switches: sound mixer before the gain knob a 20dB attenuation switch around the level, such as when .the CD audio sources from the high-impedance input come in, because the level is high, you may need to press this switch the sound source signal attenuation is only appropriate, but 20dB some sound engineer in the performance if you accidentally press the switch up ., that is: the boss is very angry, very serious consequences! now voice signals without attenuation suddenly big 20dB, consequences can be imagined, light all the listeners will be scared out of his chair jumping up to part of the sound equipment will be reimbursed .on the spot, so we're on every knob or switch for adjustment must have clear and explicit purposes, do not blindly. <br> 2 a mixer gain adjustment: some sound teacher does not know the importance of channel gain, on the knob .readily confused, and sometimes to gain knob to switch off, even while the 20dB level attenuation switch, like this time of how small? far SNR of music and dynamic, and if so it is with the microphone channel adjustment, the singer was only luck .was shouting days will not have high extremely penetrating voice; of course there are some sound teacher likes to gain to large, for music, is looked up stiffly, but music singer to laugh a bit a loud like flood broke the dam, was unable to .control, high voice becomes like breaking the gong or explosive bean-like noise, because the level is too large-signal has been severely distorted, also in this case the receiver will often return to lose. This shows gain important, maybe it will cause .a performance during the accident. <br> <br> 3 sound mixer to adjust the balance group: mixer as the name suggests is used to adjust the sound tone, adjustment or mostly depends on balancing group, said that is straightforward, the is nothing .more than high school bass plus several corresponding selected frequency knob, while tone under normal operation does not necessarily have to be very good, but will not show accident occurs, but some of the sound engineer on balance knob sometimes boldly goes, I see this sound .engineers will find alarmed, if the bass to the great, the whole amplifier and speaker's burden is greatly increased, may damage the device, the sound can also be easily distorted; if the Alto treble added to very large, the loudspeaker is dangerous, upgrade .balance knob to a degree, excessive lifting produces unpredictable failures. <br> 4. adjust the sound mixer AUX: we all know AUX primarily used to send signals to the effects, in a mixer, if we send a signal to AUX6 effects, after .effects processing to output a 2-channel signal to a mixer of 23-24-channel, then at 23-24 in the two channels will stop AUX6 knob is turned on, otherwise just after effects processed signal will then flow back into the effects. .Thus, AUX and effect between will also form a loop, when the loop level gain exceeds a certain range, it will result in acoustic feedback. In addition, AUX questions before and after the faders to note that the details in my previous article have talked .several times. <br> 5, mixer sound like: sound like a knob Hello want to make it as easy, sometimes we use only the total output of left or right channel output volume, then the sound image will note, if you use total .output right-channel output signal mixer channel sound like all play to the left, then at this point the silent failures, or just the opposite. <br> <br> 6 mixer listens and mute switch: General mixer listens and mute switch is close .together, the action must look carefully at the time, often in the press will fault monitoring switch pressed the mute switch, that cause silent failures. Remember there is a disciple, wearing headphones, in principle, all the way to go, he listens to .the signal by several channels also accidentally male singers channel mute switch is pressed, the results of his own wearing headphones and enjoy pure band voice, singer rushIt took the microphone ran kick tone control room door, so be careful when you do, and live sound .engineer cannot always wearing headphones, so there is no overall concept. <br> 7, mixer marshalling issues: group to channel the sound is, of course, easy to control, but as the Group button smaller and more, so be sure to carefully ., there are times I finished a project after acceptance to the dance hall audio engineer, I put all the musical series at 1-2 formation, singer microphone series in 3-4, when the band is 1-2 group is turned on, when .the playback singers CD or MD 1-2 when grouping is turned off, mainly in order to reduce the noise, but at this point a female vocalist microphone sound is very small, only empty effect sound there is no direct sound, I ran to the .mixer where a look at the original singer microphone to the addendum to the 1-2 group, said the band in concert at 1-2 group open, now on CD accompaniment is 1-2 Group switched off the microphone female singer sound natural, then .I get the female singers that channel 3-4 grouped according to the group by 1-2; failure to exclude, on this aspect of the mistakes I think a lot of audio engineers have had; also some advanced mixer with marshalling mute function, for .example, we want to put the sound mixer 1-10 Channel series to marshalling mute 1, when you press the button mute Group 1 total, 1-10 channels are muted. So has this capability a mixer on marshalling mute operation must see clearly. .<br> <br> Insert the plug out of the mixer INS Jack: some do not understand this audio in Jack on how to use them, if you accidentally put the plug INS inserted sound mixer out Jack, insert a TS connector of signal cable .to the sound mixer that road total output will not sound. This area describes in my previous article also talked. <br> 8, mixer interference sources find: sometimes sound mixer, there will be interference noise, all tap channel switch is closed, simply .open the total volume of the mixing console, there are a lot of noise out, this time we can put on headphones yilulu listens, and see what all the noise is the sound mixer, or sound mixer yilulu Eagle's input line and even output line, .and so on which all the noise to disappear, you find the source of the noise. On how to deal with interference noise in the following article will tell. <br> 9, the Mirage power mixer: most of the mixer will have within a .48 volt phantom power, which can be used to promote a variety of capacitor microphone, but because it is from the microphone line transmission of electric current, so always check the phone line, that line, otherwise the line contact when it makes a lot of .current impulse sound. There is also a phenomenon that is: If you use a mixer with a battery of capacitor microphone, do not open the phantom power, otherwise they may interfere with each other, can make it rain "sand" in General. Now .some will open Mirage power mixer makes a lot of current impact sound, so be careful. <br> <br> Equalizer: <br> <br> Equalizer is the peripheral equipment with the greatest number of devices, so we also need to pay .special attention to the following that adjust Equalizer is need to pay attention to some problems and troubleshooting: <br> There are some sound mixer will have 7-9 equalizer, the equalizer only simple adjustment of timbre, belongs to a secondary character, so we .use it is best not to such an equalizer for big upgrade, otherwise the mixer main output level tend to be exceeded. Then an equalizer in general have a switch, use this switch when you want to pay attention. <br> <br> Some .dual channel 15 Equalizer will have a State transfer switch, you can handle double-channel 15 Equalizer converted to single channel 30 equalizer, you will have to pay attention to see every section and then adjust the frequency. <br> 3, we currently use .the most is the dual channel 31 equalizer, note the following points: <br> <br> A.6dB and 12dB switch: there are some Equalizer 6dB and 12dB working state transfer switch, normally or adjust better at 12dB <br> B high .-pass, low pass, or: some equalizer has low pass and high pass adjustment function, adjustment, note that if you put too much bass attenuation of the sound is not too thin a full; the treble attenuation of too much sound too gloomy not .penetrating power. <br> C, frequency sliding key: adjust when the equalizer for each frequency sliding key to see if normal; at the same time note sliding keys don't do too much decay or upgrade, especially when upgrading will not exceed 6 .dB. <br> Connection: Equalizer input and output are XLR card Lennon and TRS two ports, in addition to the shape is not the same, the function is the same, but in fact are balanced line port, so we connect the equalizer to .use when you "signal cable XLR card and TRS6.35 stereo signal cable to do the balance connection. <br> <br> (Iii), to press for: <br> <br> The primary function of the compression filter is, .of course, protection equipment, adjust compression below that you need to pay attention to some problems and troubleshooting: <br> <br> THRESHOL of noise gate: compression of noise gate may not really be able to get rid of the music of the noise ., it is only useful in systems with no audio signal is in effect, such as: meeting of the leaders in low voices whisper, such unwanted sounds can be used to block the noise gate; but when the leadership of microphone more loudly, noise gate ., of course, will not be able to intercept it, otherwise there is no sound out what can do? truth is: when the system useful audio signal burst noise gate threshold level (THRESHOLD), the threshold level has no effect, the system of .noise will inclusion in useful audio signals transmitted together, but at that time was the noise of useful audio signal masks, we don't recognize it. Therefore, the noise gate is no way to eliminate the normal audio signal in any noise, it is .not like audio workstation in noise sampler that can moderate the Elimination of some of the normal audio noise. Noise gate if adjusted too high music appears "breathing space" phenomenon, it is about without the intermittentSo to avoid this kind of human failure. <br .> Compressor's THRESHOLD: compressor section of the THRESHOLD and noise gate THRESHOLD although in part is a kind of threshold circuit, but both function and work status is not the same, two threshold in normal use, the noise gate THRESHOLD may in 99% of time .does not work, because most of the audio level signal will be higher than the threshold; and the compressor THRESHOLD may in 70-90% of the time does not work, the opposite is because most of the audio level signal may be lower than the .threshold. <br> <br> Compression RATIO: adjustment of the compression ratio is determined from the compression is turned into a "comp" or into the "limiter" and its adjustment to combine compressor section of the THRESHOLD, the compression ratio is too .low to no effect, too high and sometimes damage the sound quality. Basically less than 1: 6 ratio of compression, the compression feature is greater than 1: 6 compression ratio can be regarded as a limiting functionality. Of course I personally feel that compression .ratio adjustment at about 1: 3 is quite appropriate. <br> <br> Stereo chain: compression with a stereo chain key (StereoLink), everyone in the adjustment to be careful not to accidentally press this key, as will the stereo signal into .Mono signals. <br> <br> Through Bypass: I often find that some audio Division has the express compression is still unknown, can't tell what is express state what is working, therefore this point to note. <br> Compressor failure .examples: <br> <br> There is a time-based maintenance to a set of audio equipment, found one compressor for work not quite normal, compact lamp 3, 4, and the other side of the compact led should light up 7, .8, but in front of the compression for all devices are working properly, can only be a compressor for itself. Later discovered that the compression is on the back panel has the side-switch on-20, normally to select + 4dB level worked, .and other device-level mismatch, compressor for signal easily severely distorted. We use the time do pay attention to avoid this kind of failure. <br> <br> E-modulus prescaler: <br> <br> E-modulus prescaler main .features of course is to give different speaker assigned different operating frequency, and of course protect speaker function, the following saying of adjustment required electronic dividers to pay attention to some problems and troubleshooting: <br> <br> 1, crossover point: in a .2-frequency of the sound system, normally crossover point in the vicinity of more appropriate 130Hz, but in many cases, adjustments to the crossover point is not actually depends on bass speaker, but settled on the treble or full-frequency sound. Because bass .speakers work in 300Hz following can, but some in the treble, and full-frequency sound speaker diameter is too small, the dynamic range is not large enough, you must work in order to ensure the above 200Hz their safety, if in this crossover points .in the vicinity, then these 130Hz treble speakers work looks very dangerous, so in effect and safety among them or to find a balance. I think dual 15-inch wide-band master sound box it is best not to go through electronic dividers; single .15-inch flexible main speakers; and single 12 inch below the main speakers the best e-mail divider, at least in the above job security 180Hz. <br> 2. volume control: whatever is enter level or adjust the output level, when .you want to have a degree, don't drive too big. If you are an individual dividers on volume knob are open to a large, systems of sound pressure is not enough, it will adjust the electronic divider in front of the device's signal level .or adjust the electronic dividers following amplifier's level and the volume switch. <br> 3 button: there are a number of e-modulus prescaler has one: × 10 buttons, we take care not to press it lightly. For example our crossover point adjustment .in 200Hz, press this button to 200 × 10 becomes 2000Hz, so unless it is required, otherwise generally do not press this button. <br> 4, bass mode: some electronic dividers back panel has a bass mode choice, it can take 2 .-channel stereo signal mixed into 1 channel Mono signal, which can reduce the bass sound interference between the speakers. You can use the following as appropriate. Of course if the bass frequency points higher, then the bass speaker sounds will have a certain direction, .at this point or 2-channel stereo signal of State work better. <br> <br> Stereo mode and mono mode: currently we are using most electronic dividers are mostly of 2 frequency, taking into account the flexibility and versatility, these electronic dividers .of the back panel of the General Council has a stereo and mono mode switch, if you put the switch on the Mono working mode, then at this point the electronic dividers from a dual-channel electronic 2 frequency divider becomes a single-channel 3 - .ne divider. So unless necessary not to easily convert this work switch, otherwise e divider output signal behind the output frequency of the signal would be quite different! minor worsened the sound, to also be damaged equipment! <br> <br> System bass .signal output and treble signal output must not be confused, or treble signal to the subwoofer speakers, bass signal to a high-pitched sound, so diametrically opposed approaches sound system is really no sound comes out, because the frequency wrong! maybe also burned speakers .! <br> <br> (5), the feedback suppressor: <br> <br> Feedback suppressor's main function is to prevent the system produces a transfusion, protect the speaker device, following that adjust the electronic divider need to pay attention to .some problems and troubleshooting: <br> In the use of microphone for feedback point suppression, it is best to find a few frequently used the microphone, but when you want to continue to transform the location of the handset, you can also place the point .when the adjustment of background music or microphone to speak some words, which can make the sound more active, more precise and fast find acoustic feedback frequencies. <br>> <br> 2. the system if you have to press the device, also .note the compressor for pass-through, and adjust the completed and then restored. Whereas the system of other audio processing equipment such as a mixer, equalizer, Exciter, divider, amplifier, etc, to adjust to normal working condition. <br> 3 .. takes note of the detection of a system in the feedback suppressor on the music signal and microphone feedback signal detection method of resolution is: turn off all the microphone, the feedback suppressor thread in any of the music signal channel, it is best to put .a disco music, constantly increasing volume of this channel, if it is found that the feedback suppressor started working and serious impact on the sound quality, it proves that this feedback suppressor is not perfectly. <br> 4, there is one thing to note .: If you have to readjust the feedback suppressor, the on-site performance, do not press the Reset button, as this will give you a previously set all parameters in the clear, the feedback suppressor into just the factory's original state, it is very .dangerous, the system will probably appear strong screech, serious but also equipment. <br> <br> 5 some feedback suppressor with automatic and manual work mode, if you think you have a perfect adjustment of the system does not occur with acoustic feedback, .then you can leave feedback suppressor on manual or lock mode, so that both preserves the device in the original parameters, not because the device error detection and false starts and change the parameters have been adjusted well. <br> 6, there's one more thing .: feedback suppressor is impossible both inhibit acoustic feedback and adjusting the sound field, adjust the sound field need to have a dedicated simulation multi-segment room equalizer or professional digital parametric equalizer. <br> <br> <br> <br>.