Q. Can I use DJ Setup as a Live Mixing Setup?
Yes, You can use the same setup, you just need to use a Live Mixer instead of the DJ Mixer. Choose the Live Mixer as per microphone inputs and other functions required. Lets say you currently require 8 mics to be connected, it is better to go for 12 mic inputs looking at future expansion. Furthur you could also look for features like Effect processors, Phantom, Individual PFL, Mute, Groups, Sweep Mids, Inserts amongst others
You also would need a variety of Wired and Wireless Microphones depending on the application, Check the microphone page for more details
Q. How does EQ231FLS help to locate remove feedback ?
In most Live applications, the feedback (Howling sound) is one major problem. The EQ231FLS helps you in locating the offending frequency. The LED on top of the slider which is causing the feedback will glow . By moving this particular slider downwards, you effectively remove the feedbac
Q. ABOUT EQUAIZERS? ?
Different Venues and Studios exhibit vastly different characteristics. You need a good graphic equalizer to compensate for the acoustic deficiencies in the room. Some rooms are too boomy, others reflect mids etc. Remember an Equalizer should be used mainly to cut frequencies and not boost them.
An equalizer is also required to compensate for constant directivity horns. Most current horns are CD horns- older versions, were generally exponential horns which had a very beamy effect i.e. the sound projected in a straight beam and fell off fast on each side, the highs were great on-axis but nearly non existent off axis.
CD horns addressed this problem and were had a lot better coverage. The only problem with CD horns is that the higher the frequency, higher is the loss in throw, therefore an equalizer helps in a great way to remove this major defect of CD horns
It is also a reason, why most half baked technicians recommend a “V” type of Eq setting, because they saw someone else do it.
Q. Why ACTIVE X OVERS?
Active Crossovers are very much more efficient than passive ones as amplifier power is not wasted. Passive Crossovers waste upto 30% of amplifier power.
In a good crossover, the low pass is rolled off (attenuated ) generally 24 dB per octave above the crossover frequency. The high pass is rolled off (attenuated) below a certain crossover frequency at a rate of 24 dB per octave. High and low outputs are connected to the inputs of two separate power amplifiers whose respective outputs are used to drive the high/ mid end and low end of sound system.
Q. SOME GENERAL INSTALLATION PRECAUTIONS:
DO NOT : run microphone cables near mains, data, telephone or 100V line cables.
DO NOT : over-drive the mic inputs. (In certain PA applications an extremely high speech signal is fed to the microphone. This results in a highly distorted output, thereby damaging driver unit/ speaker voice coil). For such applications connect the microphone through an attenuator to the amplifier.
AVOID : jointing the microphone cable; when this is unavoidable make sure a good screened connector is used e.g. XLR.
ENSURE : that all loudspeakers are in- phase.
ENSURE : that there are no short circuits on the loudspeaker line before connecting to amp
Q. What should you look for in an Profesional Power Amplifier ?
Confusions reigns about Power Amplifier specifications. Everybody calls their Amps Professional Power Amps. TO PHIR GEHU AUR KANKAR KA AANTAR KAISE PATA KAROGE? i.e. How do you separate the wheat from the chaff ?
1) You need to have High Damping Factor for controlling the woofer excursion with no loss of signal intensity. A minimum damping factor in the amplifier should be > 500 for an 18” subwoofer. Higher the damping the better is your cone control. This is very good for Bass and subwoofer applications. It also makes the sound a lot tighter. A high damping factor also makes your mids sound crisper. For Full range and Mid Highs application, damping factor of >300 is good
2) Signal to Noise Ratio Any electronics generates noise during operation. The amount of noise is desired to be as low as possible, the audio signal can be deteriorated with higher levels of noise. The signal level in dB v/s the noise level in dB is better know as S/N (Signal to Noise) ratio. This directly affects the dynamic envelope of the system, the higher the number the better.
3) Distortion The most important criteria is the amount of distortion generated by the Power Amp, Local PA and cheap amps have an unacceptably high level of distortion at their rated power. Locally made Amps have distortion figures of nearly 2% at their rated RMS power i.e. an amp rated at 1000 watts at 2% distortion is actually only about 700 watts at 0.5% distortion. So you get less while you pay much more.
.
4) H Class is recommended for Bass & Sub bass Applications & AB Class for full range & MidHigh applications.
5) Check the RMS rating at 8 or 4 Ohms as this is more likely to tell you about the amplifiers tonal potential. The amplifier usually operates under heavy stress at 2 Ohms and lower, so performance at 2 ohms is usually not as efficient as at 4 ohms or higher. The Damping factor reduces as effective impedance is reduced.
6) Built in High pass and low pass crossovers it is very convenient for beginners, for easy quick and reliable setup with no confusion as the easiest way to spoil sound is by using wrong crossover frequencies. In pubs and restaurants this feature is an excellent solution. It also comes in handy when the main crossover system faces a technical problem.
7) Protections : Power amplifiers should be protected against all kinds of malfunctioning.
8) Parallel output : In this mode, you can operate both the channels of a stereo amplifier on the same signal, Please note this not a BRIDGE MONO operation. It simplifies cabling and reduces the requirement of distribution amplifiers
9) Proper Selection of RMS Rating in an amplifier: Typically you should choose amplifiers at about 50% more power than the speakers at the rated impedance. This will give you enough headroom to handle musical peaks {transients}. Lets assume you want to connect a 600 watts RMS @ 8 Ohms loudspeaker on each side, the amplifier should have a minimum rating of about 900 watts RMS @ 8 Ohms, so that you have sufficient power to drive the speakers without the amplifier clipping. Clipping causes audible distortions and reduction in efficiency and leads to speaker damage.
10) High tolerance quality components and sturdy construction.
11) Your ears: Let your ears be the judge, taken an A & B demo of brand X amps V/S. NX Audio, Proton, Phonic on similar set-ups using the same CD's, speakers and levels, listen to them flat (without equalization). If it sounds great it's a good amp, otherwise it is giving you heavily colored sound & is as good as a piece of junk.
Q. What are some of the most likely causes when an Amplifier or Speaker blows (breaks down)?
Some of the likely causes are listed below
1) Too many speakers connected in Parallel, thus lowering the effective impedance below the threshold of the amplifier. Please check the lowest recommended impedance of the amplifier. Lets assume you connect 6 speakers of 8Ω each in parallel on 1 channel of the amplifier, which is rated at 2 ohms, you will have 1.33ohms, this will lead to overheating and long term damage to the amplifier and also may damage the speakers as distortion increases due to over heating
2) A very popular misconception, that speaker should be more powerful than the amplifier. If an amplifier is too low powered for the speaker, say a 300 watts RMS @ 8 Ohms amplifier per side to a speaker rated at 500 watts RMS @ 8 Ohms, the speaker will not work to its full efficiency and the amplifier will over driven causing heavy distortion which will cause damage to the speaker and is the most common cause of speaker blowouts . Big Amp = Less speaker burnout……not the other way round.
3) Another reason is an amplifier too powerful for the speaker, though not as dangerous as under powering. Lets assume you connect a 1000 watts RMS @ 8 Ohms amplifier per side to a loudspeaker rated at 400 watts RMS @ 8 Ohms. Ideally the amplifier should be 600 watts RMS @ 8 Ohms maximum. Most folks throw “ extra watts” at the same speakers. It is better to add extra channels of amplification in combination with additional speakers.
4) Trying To Cover Outdoor Gig With Your Indoor System.
Outdoor gigs require at least 12 dB (16X power) more sound output than indoors, and as much as 20 dB ( 100X power!) to really do it right
5)The impedance measurement of the loudspeaker has to accurate and correct. Whereas, many speakers rated at 8 ohms, infact are lower, as lower impedance increases output, so many unscrupulous manufacturers smudge specs, which is very dangerous and will cause heavy damage to the amplifier
6) Excessive EQ The classic “smile” EQ curve is actually smiling at your speaker's imminent demise! Keep in mind that EQs are best used for cutting, not boosting the signal. Need more highs? Reduce the bass…Need more lows? Reduce highs.
7) Shorting of speaker wires due to carelessness is the one of the largest reasons of speaker and also the amplifier blowing.
8) Using cheaper and thinner gauge of speaker cables, results in signal losses and also lowers the effective damping of the system. This can damage speakers as cone control is not very effective and the speaker and amplifier are over-driven and at risk. The length of the speaker wire should be considered when considering wire gauge. The shorter the run, the smaller gauge you can use with minimum power and damping factor loss. The longer the run, the heavier gauge you will need, to minimize power and damping factor loss. The larger the amplifier, the heavier gauge you will want to use.
9) The mains voltage has to be within 210 volts -240 volts at any given time. Also the Frequency should be 50Hz suitable power supplies / Stabilizers should be used incase the voltage or Frequency is lower or higher. When using Generators use a volt and frequency meter to monitor the power.
10) The amplifier should have adequate ventilation in all type of setups with adequate circulation of air. Very Important Don't put anything on top of the amplifier as it obstructs ventilation.
11) Sudden Transients While Speakers Are Hot.
Turn off thumps, plugging/ unplugging microphones, dropping microphones etc.
12) Make sure all the speakers are in Phase, as speakers which are out of phase will cancel each other and drastically reduce Bass and High frequencies. This results typically in over driving the amplifiers and speakers, thereby causing damage.
13) Very Important, if an amplifier is shutting down (Tripping), This is a symptom that something is wrong with the system. Usually one of the above factors is in play.
14) The Controls at the front of an amplifier are not volume controls BUT gain controls. They do not limit the power available from the amplifier. It is theoretically possible to get full output from the amplifier with the controls almost off. Most beginners keep the amplifier gain controls very low, as they are used to cheap PA amplifiers with high THD (Total Harmonic Distortion), where taking the controls above 50% increases distortion tremendously,. In a Pro Grade Power amplifier the gain controls should be ideally kept at 80% to 100%. You can regulate the output from the mixer. Make Sure that THE SIGNAL IS NOT CLIPPING BEFORE IT GETS TO THE POWER AMPLIFIER.
15) Frequent Occurrences Of Hard Feedback can damage your speaker If you go “ouch” after that last squeal (whistle), chances are so did your speakers
Q. Can I use + 48v Phantom supply with dynamic microphones connected to the mic XLR inputs in a Live Mixer ?
It is possible to use BALANCED dynamic microphones when the + 48v phantom is ON. The microphone coil 'floats' up with the voltage preventing damage to the microphone by ensuring ' zero' volts across the microphone coil. If the dynamic microphone is configured UNBALANCED ( where pins 1 & 3 are connected together), then the dynamic microphone will be damaged.
Q. Why do you need individual channel of ON/OFF or Mute in a Live Mixer ?
In a live gig, channel mute helps you switch off mics/which are not currently in use without disturbing channel settings, saves you the headache of resetting everytime a mic or any other input is introduced or removed from the mix.
Q. Why are there so many knobs to EQ in a Live Mixer ?
The equalizer section allows you to change tone of the sound on each input. An EQ is normally split into “ bands” which is control a range of frequencies, in a similar fashion to the treble and bass tone controls on your Hi-Fi. Indeed a simple “2 band” EQ is little more than an input treble and bass control. The more bands and EQ has the more sophisticated it is. Most NX-Audio have a 3 band EQ, with a separate control for the middle audio frequencies. This control is also known as “swept' mid which provides even more sophistication. Simply described, a sweep EQ allows you to choose the exact frequency to cut/ boost, than having it chosen for you, as on normal “ fixed “ controls.
Q. Is an insert jack an input or an output in a Live Mixer ?
It's both! All the signal from the corresponding channel, sub- group, or mix bus is sent through this jack. The tip of this jack is an output, which is commonly used to send signal out to a serial processor (compressor, equalizer, sonic maximizer, etc,): the ring is an input which allows signal to return from the processor; and the sleeve is a ground connection. It creates a loop, which is formed when a signal processor is inserted between the output (tip) and the input (ring). The insert jack can also be used as two different types of direct outs, either with signal interruption or without interruption.
Q. Do the Line Jack inputs have +48v on them when the +48v Phantom supply is on in a Live Mixer ?
No. It is perfectly OK for line level audio sources to be connected to a console when the + 48v phantom supply is active on the XLR input connectors.
Q. What do I use Auxiliaries for in a Live Mixer ?
Typically, these controls have two functions: First, to control the levels of the signal going to effects units, and second to create separate musician's mixes in the studio or on stage. Effects use POST fade aux sends. Foldback mixes require PRE fade aux sends.
Q. What do I use Line inputs for in a Live Mixer ?
For plugging in “ Line Level” instruments such as Keyboards, samplers or drum machines. They can also be used to accept the returns from multitrack tape machines & other recording media.
Q. How does True Diversity help in PVD58 Series VHF Wireless Microphone system
PVD 58 Series receiver utilizes two separate antennas and two separate tuners. An "intelligent" circuit in the receiver automatically selects the better of the two signals, or in some cases a blend of both. Since one of the antennas will almost certainly be receiving a clean signal at any given moment, the chances of a dropout occurring are reduced.
Q. Correct placement of Wireless Microphone system
Proper placement of receivers involves electrical concerns as RF interference, hum or other electrical noise induced in the audio circuits is possible. Receivers should be kept away from RF noise sources such as digital processors, computers and video equipment. It is strongly recommended that they be mounted in a different rack separate from other equipment. Antennas from these transmitters should also be at a sufficient distance from receiver antennas. Obviously, if receivers are placed in metal racks or mounted between other metal devices it will be necessary to make sure that antenna function is not compromised.
Q. APPLICATION NOTES FOR WIRELESS MIC SYSTEMS
Presenters .... lavaliere/bodypack systems, allows hands-free use for a single speaking voice.
Vocalists
The usual choice for vocalists is a handheld wireless microphone for close pickup of the singing voice.
Aerobic/Dance Instruction
Aerobic and dance applications require headworn /bodypack systems, to allow hands-free use by the instructor.
Theater
Theater applications call for lavaliere/bodypack systems. The intent is always to get the microphone as close to the performer's mouth as possible without being visible. Headworn microphones have become much more common in theatrical applications
Worship
Worship services may include the Handheld as well as lavaliere/bodypack wireless microphone systems. Note that headworn microphones like NANO3HS are becoming more acceptable for worship applications.
Film/Videography
Film and videography applications usually call for lavaliere/bodypack wireless microphone systems. The C77Duo can be used in conjuction with Bodypack wireless system.
|
