Unit 48 - Setting up a recording and performance session

Unit 49 - Setting up a recording and performance session

•Setting up equipment for a live performance

–Process/steps taken

–Risk assessment

•Using microphones and effects

–Microphones, how they work and different types

–Effects, how they work and different types

Equipment List:

•Mixing desk, Yamaha EMX 5016 CF 

•Power Amp, ASX 18 dB Technology for mixing desk, the t.amp A1400 for main speaker, the t.amp A 2400 for the sub speakers

•Sub Speakers (dBs)

•Main Speakers (dBs)

•Support pillars

•XLR cables

•Speakon cables

•Jack cables

•Masking Tapes

•Power leads

•Shure SM58 microphone

Process of setting up a PA:


- Firstly move the amplifiers and mixer into place within their flight case.

- Once in place lock the wheel cases into place.

- Furthermore take of the flight case lids by following the secured mechanism and place lids to one side.

- Move the base bins into position: one left and one right of the area.

- Ensure the mixer is centrally behind both speakers to help ensure sound levels during production.

- Add the pillars to the base bins and secure them tight

- Leading from this set up the main speakers on top of the pillars making them the same height

- Ensure the speakers are tight

- Check for any hazards/posing threats

- Continue to connect the Speakon Cables to the power supply 

- Connect the mixing desk to the amplifiers with Jack Leads (balanced)

- Plug the amplifier and mixing desk  to mains 

- Make sure all of the cables are taped up and out of the way

- Again check for any hazards/posing threats

- Flatline the desk before switching it on to stop any bad noises

- Add an XLR into the desired channel onto the desk for the microphone

- Turn on the desk and check the settings and levels

- Continue to turn on the speakers and check settings and levels on the speakers

- Finally test the levels of the speakers using the microphone and adapt to suit

Risk Assessment:

Risk –                                                  Solution -

Lids from boxes                                                   Ensure to put to one side out of the way and nowhere anybody would be working. Keeping the flat and tidy.

 Tripping over cables                                         can be solved with simple cable management placing them out of the way and taping them down however ensuring this does not cause any lose connections.

Live Wire exposure                                            before plugging in cables ensure that they are not broken in any way checking the safety doing so.

Plug Sockets                                                        When the equipment is not in use or is not set up correctly make sure the power is turned off.

Moving Boxes                                                    This can be controlled by locking the wheels at the base of the box.

Lifting Equipment                                              This is a health risk, which can be minimalized by ensuring to bend you knees and keep your back straight avoiding any posing threat of damage to the back.

Water near equipment                                        Keep food and drinks away from the performance area unless water is required for the performance, in this case make sure it is in a secure place and position to minimalize spillage threats.

Noise Levels                                                        For social law reasons any sound cannot exceed 120db and this can be prevented with sensible sound control on the mixing desk and the ability to check the sound output level during the performance.

Feedback                                                              Feedback is an annoying noise distortion as the sound travels back and forth superimposing with one another causing it to get louder and louder therefore hurting people ears. This can be prevented by keeping the microphones away from the speakers (preferably behind).

    

Microphones – Key Terms:

Transducer                                                           A transducer is an electronic device that converts energy from one form to another.

Diaphragm                                                            This is a thin piece of material (such as paper, plastic or aluminum), which vibrates when it is struck by sound waves.

Electromagnetic Induction                              A dynamic microphone operates through a concept called electromagnetic induction. Put simply, sound waves travel past a small metal plate called a diaphragm, which is attached to a coil of wire surrounded by a magnet. When the coil vibrates within the magnetic field in response to sound, electric current is produced, thus converting sound energy into electric energy.

Capacitor Plate                                     A nearly constant charge is maintained on the capacitor. As the capacitance changes, the charge across the capacitor does change very slightly, but at audible frequencies it is sensibly constant. The capacitance of the capsule and the value of the bias resistor form a filter, which is high pass for the audio signal, and low pass for the bias voltage.


Pre-Amp                                                                is a sound engineering device that prepares a microphone signal to be processed by other equipment. Microphone signals are often too weak to be transmitted to units such as mixing consoles and recording devices with adequate quality.                                           

Sound pressure levels                                       SPL is actually a ratio of the absolute, Sound Pressure and a reference level (usually the Threshold of Hearing, or the lowest intensity sound that can be heard by most people).

Dynamic Microphone:

The diaphragm is attached to the coil. When the diaphragm vibrates in response to incoming sound waves,

the coil moves backwards and forwards past the magnet. This creates a current in the coil which is 

channeled from the microphone along wires. A common configuration is shown here: 

Condenser/Capacitor Microphone:

A capacitor has two plates with a voltage between them. In the condenser microphone, one of these plates

is made of very light material and acts as the diaphragm. The diaphragm vibrates when struck by sound

waves, changing the distance between the two plates and therefore changing the capacitance. Specifically,

when the plates are closer together, capacitance increases and a charge current occurs. When the plates are

further apart, capacitance decreases and a discharge current occurs. A voltage is required across the

capacitor for this to work. This voltage is supplied either by a battery in the microphone or by external

phantom power.

Effects and Dynamics:

Equalization: 

means boosting or reducing (attenuating) the levels of different frequencies in a signal. The
most basic type of equalization familiar to most people is the treble/bass control on home audio
equipment. The treble control adjusts high frequencies, the bass control adjusts low frequencies.
Equalization is most commonly used to correct signals which sound unnatural. For example, if a sound
was recorded in a room which accentuates high frequencies, an equalizer can reduce those frequencies to a
more normal level. Gives you the ability to boost high, mids and lows through frequency.


Reverb: 

A reverberation, or reverb, is created when a sound or signal is reflected causing a large number of
reflections to build up and then decay as the sound is absorbed by the surfaces of objects in the space –
which could include furniture, people, and air.Reverb simulates placing your amp in a big, reverberant, or
echo-y space, like an empty parking garage.A little bit of 'verb wets your sound, smooths it out, and helps
with the sustain.


Compression:

Compression is the process of lessening the dynamic range between the loudest and quietest parts of
an audio signal. This is done by boosting the quieter signals and attenuating the louder signals.There are
three main reasons that you will want to use compression. One is to even out a sound that is uneven in its
volume levels.The second, related use is to increase loudness.A third use of compression is to make tonal
changes, especially to drums (and sometimes acoustic guitar), by manipulating the percussive attack (the
transient) of each hit (or strum).


Noise Gate:

A noise gate or gate is an electronic device or software that is used to control the volume of an audio
signal. Comparable to a compressor, which attenuates signals above a threshold, noise gates attenuate
signals that register below the threshold. You may have recorded a great guitar part but during the parts of
the song where you are not playing the guitar amp hums. A noise gate is an effective solution as it will
simply shut during these parts and open again when triggered by the guitar playing again. A noise gate
can also be used as an effect to deliberately open and shut on an instrument to create stuttering effects and 
more.



Delay/Echo:

Delay is a simple concept — the original audio signal is followed closely by a delayed repeat, just like an
echo. The delay time can be as short as a few milliseconds or as long as several seconds. A delay effect can
include a single echo or multiple echoes, usually reducing quickly in relative level.Delay also forms the
basis of other effects such as reverb, chorus, phasing and flanging. There are several different uses for the
delay effect. A few examples are: One being Slapback: Slapback delays are very short delays, with
(usually) just a single tap. These were often used in blues and country guitar tones, and are very evocative
of those styles. Another being Doubling:One of the most useful effects of a delay is for vocal doubling.
Again, a single tap is used, and the delay time is reduced to a time that isn’t really perceived as a delay.
The effect is a very subtle chorus-type effect, akin to a double-tracked recording.

Recording Studio Set up: 

In order:

 - Log into the Mac

 - Open Cubase 7

 - Once loaded go to file in he top right corner and choose the 'New Project' option

-  Furthermore select ‘empty’ from the tab on the right (more)

 - To check the desk is set up look at the following:
         –Devices – Device set up. Check the audio driver (ASIO) is connected to the Onyx Firewire (desk).
         –Devices – VST connections. Under inputs and outputs the preset should be on ONYX.

 - Go to project – add track. Add as many mono audio tracks as you will need.

 - Change the input for each track using the bar on the right which says mono in. Each input responds to
   the input on the desk.


- Click monitor on the track (little speaker icon) to test the audio is coming through.



Checklist for Recording: 

 - Set up studio

 - Connect microphones to wall box in studio using XLR leads

 - Open mixer in Cubase to monitor levels (Devices – mix console)

- Set gain on desk – try to get performer to play as loud as they will do it for the recording, and get the
    gain to sit at 0dB on the mixer. (too high and it will clip)



 - Performer can have headphones plugged into control box in studio to hear backing track/click track.

 
- Ready to record! Press the red record button on the transport bar to test the set up.




References/sources:

http://www.mediacollege.com/audio/microphones/how-microphones-work.html

http://whatis.techtarget.com/definition/transducer

https://thetartan.org/2012/1/30/scitech/microphones

https://en.wikipedia.org/wiki/Microphone_preamplifier

http://www.nchearingloss.org/spl.htm?fromncshhh

http://en.wikiaudio.org/Microphone 

http://www.mediacollege.com/audio/microphones/dynamic.html

http://www.mediacollege.com/audio/microphones/condenser.html

http://www.mediacollege.com/audio/eq/

https://music.tutsplus.com/tutorials/the-beginners-guide-to-compression--audio-953

http://www.dawsons.co.uk/blog/what-is-delay