Extended Music Diploma Year 1: Unit 25

LO1: Describe what Microphones, Mixers, Monitors and Recording Devices are.

Microphones

Polar patterns

The polar pattern of a microphone is the sensitivity to sound relative to the direction or angle from where the sound is coming from. The most common types of directionality are Omnidirectional, Cardioid and Supercardioid.

Cardioid

A cardioid microphone has the most sensitivity at the front and is least sensitive at the back. It isolates from unwanted ambient sound and is much more resistant to feedback than omnidirectional microphones. That makes a cardioid microphone a lot better for loud stages.

Supercardioid

Supercardioid microphones offer a narrower pickup than cardioids and a greater rejection of ambient sound. But they also have some pickup directly at the rear. Supercardioids are most suitable when single sound sources need to be picked up in loud environments. They are the most resistant to feedback.

Omnidirectional

The omnidirectional microphone has equal output or sensitivity at all angles, this means it picks up sound from all directions. Therefore the microphone doesnt have to be aimed in a certain direction. A disadvantage is that an omni cant be turned away from speakers therefore can cause feedback.

Figure of Eight (bidirectional)

A fourth polar pattern is the microphone with a figure of eight polar pattern which picks up the sound from in front of the microphone and from the rear but not the side (90 degree angle). Microphones with this Figure of Eight polar pattern are mainly ribbon or Large Diaphragm Microphones.

Frequency response/Sensitivity

The frequency response is the output level or sensitivity of a microphone over its operating range from lowest to highest frequencies. Generally two types exist:

Flat frequency response

All audible frequencies (20 Hz - 20 kHz) have the same output level. A flat frequency response is most suitable for applications where the sound source has to be reproduced without changing the original sound, e.g. for recording.

Tailored frequency response

A tailored response is usually designed to enhance a sound source in a particular application. For instance, a microphone may have a peak in the 2 – 8 kHz range to increase sound for live vocals.

Types of microphones (Dynamic, Condenser, Ribbon, PZM)

Dynamic

Dynamic microphones have a diaphragm, a voice coil and a magnet. The voice coil is surrounded by a magnetic field and is attached to the rear of the diaphragm. When the microphone picks up a sound the motion of the voice coil in the magnetic field generates an electrical signal.
Dynamic microphones have a simple construction and can can handle extremely high sound pressure levels and are largely unaffected by extreme temperatures or humidity.

Condenser

Condenser microphones have an electrically-charged diaphragm/backplate assembly which forms a soundsensitive capacitor. When the microphone picks up a sound the diaphragm is set in motion. This changes the space between the diaphragm and the backplate and in doing so changes the capacity of the capacitor. This variation in spacing produces the electrical signal. Condensers are more sensitive and can provide a smoother, more natural sound, particularly at higher frequencies.

Ribbon

A ribbon microphone is a unique type of dynamic microphone that is based around a thin, corrugated strip of metal (often aluminum) or film suspended between two magnetic poles. The ribbon element responds to variations in the velocity of air particles, rather than the pressure. As the ribbon vibrates within its magnetic field, it generates a tiny voltage that corresponds to these changes in velocity. Ribbons mics have a wide dynamic range, and are capable of handling high frequencies. These mics are bidirectional by design, because the ribbon element responds to sound arriving from the front or back of the mic, and does not pick up sound arriving on its sides. This natural figure-8 pattern makes them ideal for stereo recording applications, and is useful in applications where you want to get rid of noise between two sources.

PZM

PZM (Pressure Zone Microphone) is a special type of condenser microphone. Also known as a boundary microphone, this type of microphone uses a sound phenomena called the boundary effect. PZM mics are quite unusual-looking. They are flat microphones that work best when placed against a hard, flat surface at least one meter square for example, a tabletop or wall. Boundary mics by design have very low mass and highly-damped diaphragms so they show great resistance to mechanical vibrations such as surface thump or rumble. They also reproduce room ambience with great natural clarity and brightness while having consistently good frequency response regardless of the direction of the sound source. The sensitivity of a boundary mic may be naturally increased by placing it between multiple boundaries. When positioned in the corner of a room, for example, where the floor and two walls meet at right angles, the mics sensitivity will increase by 18dB, or 6dB per surface without any increase in noise.

Mixing Desks

A mixing console (or mixing board, or simply mixer) is used for a wide variety of purposes in a computer music and recording studio, as well as for live sound and concert playback situations. Mixers are often known by their input and output (I/O) capabilities. For example, a 32 x 8 mixer would have 32 individual channel inputs and eight main output channels. Most professional boards have many more input and output capabilities besides the main I/O's. In addition, boards can serve as signal routing devices, moving audio signals from one device to another.

Routing

At any given time while using the DAW, you will be doing at least one of the following tasks: recording to the computer, monitoring an input (mic, pod pro, etc.), or listening to what you have previously recorded.

Channels

Channels on a mixing desk are the single columns that have the buttons and knobs going vertically down that allow you to increase gain, change volume, mute or solo a particular track.

Buses

A bus is basically a path in which you can route one or more audio signals to a particular destination. Destinations can include groups, auxiliary sends, stereo mix, foldback or monitor. Commonly buses are used to route channel signals to a master group fader, a multitrack recorder, or the main stereo master fader (or all).

Auxiliaries

Most sound desks include one or more auxiliary channels (often referred to as aux channels for short). This feature allows you to send a secondary feed of an input channel's audio signal to another destination, independent of the channel's main output.

Inputs

Inputs are things that go into the mixer for example, plugging in a bass guitar, you route it through the mono input 1 then using the nobs on channel 1 on the desk you can manipulate the gain and mute it etc. Each signal that is input into the mixer has its own channel. Depending on the specific mixer, each channel is stereo or monaural.

Outputs

Subgroup and main output fader controls are often found together on the right hand side of the mixer Outputs are things like talk back controls which allow conversation with the artist through their monitors, headphones or in-ear monitor.

Monitoring

The purpose of monitors are very different to that of the front-of-house mix which has to concentrate on ensuring the audience hear the best sound possible. Monitors are needed in medium and large venues to ensure that the musicians can hear themselves and the instruments around them, allowing accurate singing and playing. The monitor mix is just for the musicians and so can be completely different to that mixed for the main front of house speakers. Although FoH and monitor mixes can be produced from a single desk, the two roles are generally divided between two desks and engineers, allowing each to concentrate on their own area.

Recording Devices

D1200 recording device

Essentially, the D1200 is still a 12-track 'studio in a box' the user can chose between a 12-track, 16-bit mode or a six-track, 24-bit mode. In both modes, simultaneous recording of four tracks is possible. In 12-track, 16-bit mode, the same arrangement of six mono tracks and three stereo pairs is present, along with the nine, 45mm, non-motorised channel faders (plus red Master fader). The Korg has a maximum of eleven effects and three-band EQ on each input and playback channel. Some 200 rhythm patterns are built in and can be chained to construct a basic drum part. Scene-based mix automation is provided and the comprehensive MIDI specification allows both dynamic mix automation of key parameters and MMC control via an external sequencer. Finally, with the optional CD-RW drive fitted, audio data can be backed up, burned as an audio CD, or moved to a computer. The D1200’s ability to import and export WAV files makes for great flexibility and compatibility with computer based systems. This can be done by connecting the built-in USB port to your PC or MAC. Tracks recorded on the D1200 can be easily transferred to a computer for mastering, further tracking, or to convert to MP3 or other formats.

Tracks

On the Korg you can either have 12 tracks or 6 depending on whether you're using 16 bit mode or 24 bit mode.

Inputs

The Korg has 4 main inputs at the back however you can route one of the inputs to a different track

Monitoring

-Speakers

An electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance

Nearfield/Midfield

Midfields usually need to operate in a much bigger room, thus will be further spread apart. They will have a design that will enable them to sound good with the listener being further away then nearfields, and have a wider stereo image due to the monitors being further apart then nearfields.

Nearfilds are used if you are working in the studio or in a living room when you do not require the speakers to be extremely loud its also down to the size of the speakers the bigger the speaker you have the bigger your room needs to be.

Full Range

A full-range loudspeaker drive unit is defined as a driver which reproduces as much of the audible frequency range as possible, within the limitations imposed by the physical constraints of a specific design. Most single driver systems, such as those in radios, or small computer speaker designs, cannot reproduce the entire audio range.

Frequency Response

Frequency response is the quantitative measure of the output spectrum of a system or device in response to a stimulus for example if a sine wave is injected into a system at a given frequency, a linear system will respond at that same frequency with a certain magnitude and a certain phase angle relative to the input. Also for a linear system, doubling the amplitude of the input will double the amplitude of the output. In addition, if the system is time-invariant, then the frequency response also will not vary with time.

        Two way/Three way


-Bass Driver      -Bass driver

-Tweeter            -Mid driver

                          -Tweeter -Tweeter

There two types of speaker the first one is called a two-way speaker they are comprised of a driver and a tweeter. The driver reproduces the bass and midrange frequencies, and the tweeter reproduces the higher frequencies. There are also 3-way speakers, these speakers use a separate bass driver, midrange driver, and tweeter. The driver and tweeter are installed together into a single basket or frame, with the tweeter mounted onto a tweeter post, which is attached to the speaker in the center of the voice coil.

Passive

The vast majority of speakers are passive. A passive speaker doesn't have a built-in amplifier; it needs to be connected to your amplifier through normal speaker wire. This speaker level signal has been amplified enough to drive the speakers sufficiently.

Active

Active speakers, on the other hand have a built-in amplifier and are fed by a low level signal passed along an interconnect cable which comes from whatever controller youre using. Because the amplifier is an active electronic device it needs power which means you have to put any active speakers near a power outlet.

Genelec speakers in studio are active:

LO2: Be able to set up equipment ready for recording

Microphone Techniques

Spot Miking:

Spot miking (also called close miking) involves placing your microphone within a couple of feet of the sound source. Home recordists use this technique most often because it adds little of the room (the reverb and delay) to the recorded sound. Spot miking can help you keep multiple instruments separated in your tracks, so if you record your band live, you can create some isolation among instruments. Below is an image of me spot miking my guitar.

Ambient Miking:

Ambient miking is simply placing the mic far enough away from the sound source so that you capture more of the room sound (the reverb and delay) than the sound of the actual instrument in your recording. You may place the mic a couple of feet away from the source but pointed in the opposite direction, or you may place it across the room.

Spaced Miking:

Spaced miking is using two or three microphones spaced apart several inches to several feet apart, depending on the width of the sound source and the acoustics, for stereo recording.

Direct Input/DI:

Direct input or DI is simply plugging the lead from your instrument into whatever you're recording on for example in my case below I was recording on a Korg D1200 so I plugged my lead straight into the Korg's input 1. DIs are frequently used to connect an electric guitar or electric bass to a mixing console's microphone input. By plugging an instrument into a mixing desk or recording devise you minimize background noise, room ambience and get a cleaner fuller sound.

LO3:

Track	Instrument	Mic used/DI/Overdubbed	Position and capture
1	Acoustic guitar	AKG C1000S	Tune guitar, make sure mics are plugged in and are postioned in front of guitar correctly, then record using as a guide for the rest of the song
2	Acoustic guitar	AKG C1000S	Tune guitar, make sure mics are plugged in and are postioned in front of guitar correctly, then record over the top of the previous guitar
3	Acoustic guitar	AKG C1000S	Tune guitar, make sure mics are plugged in and positioned correctly then record over certain parts of the previous guitar part to give a rounder sound
4	Percussion (guitar body)	AKG C1000S	Make sure mics are positioned correctly but not too close incase it peaks when recording
5	Double bass	AKG C1000S	Tune the bass and also tighten the bow and make sure the mics are in the best postion to capture the sound

Me and Harry recorded the song, he played the guitar and I was at the mixing desk making sure it was running smoothly. Harry did all the guitar parts and the percussion part and we got a girl called Hannah to come and play the double bass.

LO4:

This document shows the process I went through to mix down my song: