Being a recording enginere Unit 48

Introduction to sound production 


terminology for microphones

there are five main words to remember for sound production they are transducer, diaphragm, electromagnet,  compactor plate and Pre-Amp.

Pre-Amp- this a a device that is used when you have a very weak signal, it is used to amplify the sound.

Diaphragm- this is used to produce electrical signals, this is because its a thin sheet of metal thats vibrate in response to sound waves.

transducer- this device is used to covert one form of energy into another.

electromagnet- this is what is called when audio signals are converted into electrical signals.

compactor plate-all compactors have two plates that have some voltage between them. within a condenser microphone, one plate is very light, this is so it can act as a diaphragm.

Types of microphone

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

(insert picture of mic)

Condenser/ Capacitor Microphones-

A capacitor has two plates with a voltage between them. In the condenser mic, 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  mic or by external phantom power.

(inser other mic)

Ribbon- When conductive aluminium is positioned between the poles of a magnet it produces voltage, this is what happens with a ribbon microphone

Microphones

Shure SM58-
this microphone is typically used when recording a vocals track, it is made to focus ob the main sounds and minimise any background sounds that may be picked up.

AKG D112-
this microphone is typically used for recording the kick within a drum while in a recording studio, however it can also be used for stage performances, its main feature is that it can handle more than 160dB SPL without going into distortion.

AKG C1000-
This microphone is typically used for live sound productions, its main features is that is a condenser, most microphones are dynamic.

Outside recordings

I used the a hand held recorder to record a glockenspiel in an outside environment . i recorded front, rear, Surround F, and surround R

glockenspiel outside, microphone facing forwards- https://soundcloud.com/user-318712867/outside-front-glockenspiel

glockenspiel outside, microphone facing rear- https://soundcloud.com/user-318712867/outside-recording-glockenspiel-rear

glockenspiel outside, surround F- https://soundcloud.com/user-318712867/outside-recording-glockenspiel-surroundf

glockenspiel outside, surround R- https://soundcloud.com/user-318712867/outside-recording-glockenspiel-surroundr

classroom recordings

i recorded two different instruments within a classroom, do do this i used a Shure SM58
the instruments i recorded were a glockenspiel and an acoustic guitar.

glockenspiel in a classroom- https://soundcloud.com/user-318712867/classroom-glokenspiel

guitar in a classroom- https://soundcloud.com/user-318712867/classroom-acoustic-guitar.

Evaluation

classroom glockenspiel- there is no background noise and it has displayed good use of picking up higher frequencies, actual recording is to a high standard.

classroom guitar- good sound quality, however quiet in places, there is no background noise. the instrument is clear and easy to hear, in future ask musician to play a little louder or have microphone closer.

outside recording- in all four recordings there is a lot of background noise, the instrument was places too close to the microphone their is made clear by the buzzing that is heard, scratching can be heard half way through. wouldn't recommend doing a professional recording in this setting.