Presentation
Techniques for broadcasting
.
Indoor
acoustics: the
principles of sound and acoustics;
Studio based acoustics
Acoustics in a recording studio are usually
said to be “dead” as the walls are built to have a very short reverberation
time, soundproofing is also important it has to be built to deal with low
frequencies like the rumble of a car engine or the sound of a plane. There is
also a double wall between the studio and the main building this creates the
room within a room effect which helps reduce low frequency sounds because it’s
not as strongly connected to the foundations of the other building. The dead
room is usually used to record spoken word as it gives a very clean sound.
Live rooms are sort of the opposite of a
dead room, instead of stopping reverb it increases it by bouncing the sound
around the room, and the noise it creates is very pleasing to the ear.
The surface types used in dead rooms and
live rooms are very different as a certain needs to be attained from use of
specific surfaces that either increase or decrease reverberation. In dead room foam
insulation would be used in the walls to absorb mid-range to high frequency
sound. To stop the diffraction of sound all small holes and cracks will need to
be sealed.
As you can see here the surface for a dead
room is designed to absorb all reverberation, you can see this from the picture
there are a lot of wooden slats, this eliminates any chance of sound bouncing (reverberation)
This a picture of a live room as you can
see it is very different from a dead room, not only in size but also the
material and room design. Having a big studio room like this stops the comb
effect which is usually created by having walls and ceilings very close to the performer;
the effect makes the voice sound very hollow. The hardwood is a key material in
a live room like this as it reflects sound extremely well.
Reverberation is created when sound is
produced in a small space, which causes a high amount of echo which bounces of
surfaces like hardwood, the many echoes will disappear.
http://www.keplar.net/articles/build-a-project-studio-you-can-be-proud-of/dead-rooms-and-live-rooms/
Outdoor
acoustics:
Outdoor
acoustics are very different to indoor as there are a lot of noises that cannot
be controlled as easily indoors; this means that you will always need something
that will decrease unwanted noise like wind and background noise, to do this a
wind shield is used piece of foam that goes over the mic. Sound bites are small
sound clips that last between 15 and 30 seconds, it is normally taken from a
longer audio clip.
Background
noise is easy to get rid of in a controlled indoor studio as you can edit it
out using audio programs like soundtrack pro and FL studio, when recording
outside there will be a lot more unwanted background noise, the solution to
this is to either edit it out, you will be able to get rid of most of the
unwanted noise or you can do the conventional way which is to use a wind shield
this is often the most effective.
Sometimes
you might want this background atmosphere especially if you’re making a film as
ambient noise makes the scene more real for example if two people were sat on a
beach chatting you would record the sound of waves, some birds, people running
about, this would be recorded separately from any dialogue then lay it on the
video using editing software like Premiere Pro or Avid.
.
Simulated
acoustics:
Simulated acoustics are effects that are
added in post production using sound editing software, effects can also be
added live during a performance by using an effects unit, these are normally
housed in a rack mount or amplifier, you can also get pedal boards that are
normally seen in use with electric guitars, these units can dramatically change
the sound output of an instrument.
Effects pedal
Rack mounts; these are almost electronically identical to an effects
pedal, they are a lot more complex and contain several effects. They are
normally used for studio recordings and live sound mixing; it can be controlled
by either a midi digital control interface or the musician who controls it
using a foot pedal.
Sound Processors are used to accurately
replicate characteristics of sound; they are often used on computers and are
referred to as Sound cards.
Compression is a post production process
that is done using audio editing software, compression is used to make things
louder, and this “means you turn up the levels in the mix without overwhelming
everything else”. When something is compressed it “automatically turns down the
loudest parts and keeps the average consistent this enables you to turn up the
overall level without getting distortion”. Overall compressing makes the audio
fuller and more controlled.
Computer-based audio plug-ins are pieces of
software that you buy and add to a full editing program like premiere pro or
avid, they give a load of effects that don’t come with the editing software.
For example you might have a plug-in pack that is used for EQ only or
compression.
Surround sound, this is used to immerse the
viewer of a film by having speakers set up so they cover 360 degrees, the
surround sound processor decodes the multi channel audio formats from the DVD
or TV broadcast. There a few different surround sound setups for example 5.1
surround sound which isn’t full surround sound and 7.1 which is, the 7 stands
for the number of audio channels and the .1 is the low frequency effect or LFE,
.1 is mono and .2 is stereo.
Pitch is similar to frequency, if the sound
is high pitched then it will have a high frequency and a short wave length
where as a low pitch will have a low frequency and a long wave length.
A time delay effect is similar to a reverb in
the way that it plays a sound again after a set amount of time, it does this by
using a ram buffer which stores the audio for a set amount of time before
releasing it.
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