What is Required from Sound System Suppliers
o How do
I know what sound system do I require for my event?
o Why feedback happens?
o Special
feedback with simultaneous interpretation equipment
o PA for
round tables or more than one speaker
o Types of microphones
How Do I Know What Sound System Do I Require for My Event?
The sound or audio system (known as PA System - Public Address) you will install during your event will very much depend on the type of conference, seminar, workshop or meeting you are planning to hold and the number of attendants expected.A traditional conference, for instance, can usually be managed well with one lavalier microphone for the speaker(s) and one or two hand-held wireless microphones to pass around the audience during question and answer sessions.
For the participation of the public it is also possible to use normal cabled microphones with a base places strategically around the room. Participants can then stand up and go to the microphone to ask their questions.
A cabled microphone on the podium usually does not provide the best results for events with simultaneous interpretation, mainly because the speaker tends to stand to far from the microphone. For this reason, it is usually better to use a lavalier microphone or a headset, although several speakers dislike the headset.
An important thing to consider when you decide to use lavalier microphones is that due to their high ability to detect sound (they are omnidirectional) and the freedom of movement they provide to the speaker, the possibility of producing feedback with the speakers increases significantly. For this reason it is important that you test the area well, keep a good control over the volume and warn the speaker about the zones where feedback may happen.
Why Feedback Happens?
A PA System or sound system consists of at least a microphone, an amplifier and one or more speakers. Every time you have all three elements together there is a chance for feedback to happen.Feedback is that annoying screeching noise that is heard through the speakers once in while. Feedback happens when the sound of the speakers is picked-up by the microphones, reamplified and sent again through the speakers creating a loop.
This
loop happens so quickly that
it produces its own
frequency, and that is the screeching noise we
hear. The distance between the microphone and the speakers has a lot to
do with the frequency of the noise, because distance controls the speed
with which the sound makes the loop through the sound
system. Special Feedback With Simultaneous Interpretation Equipment
By itself, the simultaneous interpretation equipment does not produce feedback whether on its own or in combination with the sound system.However, since it is also a sound transmission system, in some cases it can produce some inconveniences that can be easily prevented and solved:
Noise with
Cellular
Phones: If a cellular phone is placed too close to a simultaneous
translation receiver, as soon as the telephone rings or even
receives a
text message, the user will hear a vibration on the earpiece of the
translation receiver.Solution: Keep cellular phones away from the translation receivers.
Feedback
in One of the Receivers: If a participants takes the
microphone used
for questions and brings it too close to the earpiece of a translation
receiver, feedback will be heard in the receiver close to the
microphone.Solution: Turn off the receiver before asking a question or keep the earpiece away from the microphone.
General
Feedback in the Conference Room: Whenever there is a large
number of
translation receivers operating in one place, and several of them have
been set very loud or have been left on while laying open on the table,
the accumulation of sound from all the receivers will make its way to
the microphones in the room and produce a feedback that is actually
perceived more like a hum in the room. This feedback can be
differentiated from the feedback produced by the microphones in the
room because it can only be heard when the simultaneous
interpreters
stop talking.Solution: Tell the audience to keep the earpiece always next to the ear.
Feedback
When Too Close to the Interpreters: During events with
simultaneous
interpretation that are not using the booth for the
interpreters, if
anyone from the audience stands very close to the microphone of the
interpreters
with a receiver that is operating, feedback will be heard
on his/her receiver.Solution: Keep your distance from the table of the interpreters or use the translation booth.
PA for Round Tables or More than One Speaker
During round tables or whenever there is a head-table with several speakers, it is advisable that the sound system includes two, three or more microphones so they can pass them around rapidly and avoid having to wait for a microphone to become available before participating.Another good option is to use professional conference microphones, one for every speaker. The good thing about this type of sound system is that each speaker can open or close the microphone whenever necessary and the moderator has control over the microphones of the other participants.
When you use more than three microphones or a conference system, it is really important that a technician remains in charge of the sound system to make sure microphones remain closed during the meeting and open when someone wishes to speak to avoid feedback.
Whenever possible, it is better to have a technician dedicated to your event (hotels and conference centers in general do no assign a full-time person unless you request it). This is even more important if you do not have a person in your staff with technical knowledge of this type to solve an emergency.
Types of Microphones
Whenever you are in charge of organizing an important event for your company or customer, it is indispensable that you are well informed about the options in sound system available in the market so you can make the best decisions for your event and also avoid being manipulated by the suppliers of services and equipment (hotels, conference centers or independent companies).
Cabled
Microphones.Dynamic Microphones: These are the traditional microphones connected through a cable to the mixer. The cable used is usually a cannon/cannon (XLR3) or cannon to a 1/4" plug, depending on the mixer used. In general, these microphones do not require electricity or batteries and produce the energy they need thanks to a magnet or a coil.
Condenser Microphones: These microphones use a capacitor that moves in response to sound. This type of microphone requires electricity or batteries. Also some of them are fed with phantom power, a capacity available with some mixers.
Wireless
Microphones.Hand-held Microphones: These microphones are usually a bit larger and heavier that a traditional microphone because the use several batteries or a 9V battery. Some
of them have
a small antenna or cable, but new models do
not have any visible antennae. The signal from the microphone is
received by a receiving unit with relatively powerful antennae that is
connected to the mixer just like a traditional microphone. The
receiving unit requires its own energy source and needs to be connected
to an electric outlet.Lavalier Microphone: This type of wireless microphone is very compact. It can be placed on a tie, on the collar of a shirt or jacket or on the button line of a blouse thanks to a small clip. The microphone has a cable that connects it to a small transmitter that controls whether the microphone is on, off or muted. This is a very discreet microphone and for that reason it is often used in television programs. It also permits a wide range of movements to the wearer, and it is very common among conference speakers.
Headset Microphones: From the technical perspective they are the same as a lavalier microphone and can actually use the same transmitter. What changes is that the microphone is placed closer to the mouth of the speaker. There are very discreet units that can be coordinated with the skin or hair tone of the user, other versions are a bit more conspicuous and include a headset with a microphone placed close to the mouth. The main advantage of the headset over the lavalier is that since the microphone is closer to the mouth, the sound signal is much clearer and feedback is not produced easily.
Sound Capturing Patterns
Any of the microphones above can use one of these systems.Omnidirectional Microphones: This is a microphone that can capture sound from any and all direction. It is mainly used to capture environmental sound or in cases where the origin of the sound cannot be predicted.
Cardioid Microphone. These microphones capture the sound using a heart-shaped pattern. They are very common nowadays and very much during events because they do not produce feedback easily. This microphone blocks the sound from the backside and it becomes more sensitive the closer the sound gets to the front. It is important to note that when a person speaks very close to a cardioide microphone, the sound will be more bass and if speaks from further the sound will be more pinched.
Unidirectional Microphones. Capture sound coming from only one direction. A cardioide can be considered a unidirectional, but normally when this term is used, it makes reference to special gun microphones. These microphones are used during outdoors interviews or when the source of sound is very distant.
Bidirectional Microphones. These microphones are no longer very popular. They basically capture sound from two opposite directions in an "8" pattern.
Hard Microphone. This is not a sound pattern or working principle characteristic, but a quality and sometimes a price circumstance. Lower quality microphones tend to be what is known as "hard". This means that they are not very sensitive and for them to operate correctly, the user must speak very close to them or as it is called "eat the microphone". The advantage of using these microphones with your sound system is that, besides their price, they practically never produce feedback.
We can gladly suggest you the sound system and services that are most convenient for you according to the characteristics of your event and we can also add them to our quotation for simultaneous translation services.
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