Unit 25 Part 1

Polar Patterns  Polar patterns visually represent the source in which the microphone picks up the sound it records. In basic words it hears from a specific direction and only clearly picks up what is directed at it. The four most common polar patterns include: Cardiod Cardiod are most sensitive to the front rather than the back in order to stop the microphone recording unwanted sound. Very commonly used in recording studios and live performances. Super Cardiod Super Cardiod microphones have stronger rejection of unwanted sound however does slightly pick up some sound if pointed directionally behind it. It is much more narrow therefore monitoring speakers are best kept to the sides. Omnidirectional Omnidirectional microphones pick up sound equally from all angles. Therefore if a vocalist were to turn their head while recording, the microphone would still hear vocals without the recording being affected. Like Cardiod it’s most common use is within a recording studio. This polar pattern is good for recording atmospheres. Figure of Eight Figure of eight is simply bidirectional meaning it’s most clearest recordings are from front and back. In this example 2 vocalists can be either front or behind the microphone but not so much at sides. This is typically used for Ribbon Microphones.

 Cardiod and Super Cardiod polar patterns are the best choice for live performances as it will only pick up the vocalist or instrument it is recording while eliminating any unwanted background noise. Dynamic microphones usually use this polar pattern the most.  Omni directional polar patterns are great for ambient miking as an Omni-directional pattern records everything around the microphone. For example if someone were to attempt to record the sounds of a forest, Omni-directional microphones will record everything from each angle within the atmosphere.  Figure of eight polar patterns are an excellent choice for recording 2 people at the same time. As it records from the front and back the two vocalists can record facing each other. Where is each Polar Pattern most necessary?

Frequency Response and Sensitivity  Flat Frequency Flat frequency response simply means that the rawest form of a speaker’s voice will be recorded. Therefore this sound will have to be reproduced and is not changed during recording.  Tailored Response Tailored frequency means quite the opposite. In this case the voice is enhanced during the recording by a couple of kHz in order to make the voice sound more professional. This is most useful for live radio.  Sensitivity How much sound you will pick up is based on the sensitivity of the microphone. If too little the microphone will not receive much sound even if wanted where as if too much the microphone risks being blown up due to the signal breaking it down.

Condenser The condenser microphone is usually used for inside studios, radio shows and home recording. Within are 2 metal plates. 1 made to act as a diaphragm and 1 that is fixed. Acoustic energy varies in electrical charge. There are 2 types of diaphragm. 1 example of small is Mojave MA-100 having Cardioid and Omni-directional polar patterns. 1 example of Large is Mojave MA-300 possessing both polar patterns and a Figure of 8 polar pattern. The condenser needs internal or external power to work which is known as Phantom Power. It can sometimes be expensive depending on quality of sound and humidity can effect it’s performance. It is best for recording Cymbals, Drum Overheads, Piano, Acoustic Guitars, Vocals and String Sections. The image to the right is an example of a condenser microphone. It is the AKG C451B small- diaphragm condenser microphone.

Dynamic Dynamic microphones are the most robust and inexpensive. Shure SM58 is a good example with a Cardioid polar pattern. Despite it being so thin the Diaphragm is quite heavy and is less sensitive to high frequency. Inside it has a coil wrapped around a magnet and moves creating a current turning acoustic energy into electric energy. It has no need for external or internal power and it’s resonant peak is in mid frequency. This image is the ADM Professional Cardioid Dynamic Microphone. It has a cardioid polar pattern and has a frequency response of 100 – Hz.

Ribbon An example of a Ribbon Microphone is Royer R-121 with a figure of 8 Polar pattern. It’s diaphragm is a thin strip of aluminum and although it is not very strong and breaks extremely easily it has a great high frequency response and is quite expensive. Due to the diaphragm being so thin it is less sensitive and has a weaker output. It does not need internal or external energy and is good for recording Cymbals, Bass, Piano, Guitars and Brass Instruments. This image is the sE Electronics R1 Ribbon Microphone. As with most ribbon microphones it has figure of 8 polar pattern with a frequency response of kHz.

Boundary The boundary microphone is very low in mass. Within the highly damped diaphragm are tiny condenser capsules making it practically a condenser microphone with a smaller diaphragm and an Omni-directional polar pattern. It can be discreet and also have a higher frequency dependent on where it is placed. The image on the right is the SUPERLUX PRA- 428 Cardioid Boundary Microphone. It is uni- directional and has a cardioid polar pattern with a dynamic rae of 115 dB.

Examples  Condenser - During this recording, as the two were having a conversation they would use a condenser microphone in order to catch each other’s voice as clear as possible.  Dynamic - Dynamic microphones are used in live performances and examples such as this due to the fact that they are less susceptible to feedback and are better at controlling spill that wasn’t intended to be amplified.  Ribbon - Ribbon microphones are quite common within sports commentaries. They were in high demand especially during the 1930’s to 1950’s due to their high frequency response.  Boundary - Boundary microphones are most commonly used in conference meetings in order to record conversations.

Mixing Desks  A mixing desk is a routing path which can transfer sound from audio signals. The input section is where the signal will travel to. The monitoring section is where you listen back from. A copy of the inputted signal will reach it’s destination from here. This is where the signal and final sound comes out. This is where you optimize the signal gain before it reaches anywhere else. This is where the microphone levels are monitored. This allows effects to be added to an audio source or channel.

Busses & Auxiliaries  Generally speaking, a Mixing Buss is simply a signal path. It is used in order mix audio signals via combining the electrical signal which carry the audio. It is necessary to use a mixing bus as under average circumstances, it would be impossible to connect the outputs of several pieces of equipment to a common destination. This signal is then sent to the mix amplifier, and then the master level fader. Another popular use for busses is parallel processing by sending your drums, vocals or entire mix to two stereo busses.  Auxiliary cables are very commonly used for personal headphones, home entertainment systems and different types of stereos. An ‘aux’ can sometimes be considered a form of mixing buss as it creates 'auxiliary' mixes alongside that of the main mix bus. Each channel that it being processed into the auxiliary cable will have a certain level of control over the signal that is being fed.

How Sound Travels Once a sound is created it will travel into the diaphragm of the microphone or recording device. Once it reaches the diaphragm of the microphone a vibration is made to imitate the sound in as good quality as possible. Basically the way an ear would work. The sound it imitates will be sent through the body of the microphone and a signal will be sent to the mixing desk it is connected to. Once it reaches the mixing desk via the input section, it is optimized. From the auxiliary send, a copy of the signal will be sent through the auxiliary returns in order for effects to be added and into the output and monitoring sections. The monitoring section allows you to listen back and signal travels through the output into the speaker it is connected to.

Recording Devices  Roland R-26 The Roland R-26 is a portable hand-held recording device. Up to 6 tracks can be used for editing and recording on this device. It has an omnidirectional and directional microphone built in and an XLR and TRS combo input with 48 V Phantom Power. It can be connected to a computer via USB and used as an audio interface. It has a sample rate that can reach up to 96 kHz and a bit-depth that can reach 24 bits.  Audacity Audacity is a computer-based digital audio workstation and multi-track audio editing application used for operating systems such as Mac and Windows. Audacity can records sound from a microphone, mixer or other media. It can have as many tracks as possibly needed and can import and export audio files such as MP3, WAV, AIFF, AU, FLAC and many others. As it is a computer based program connected anything to it is as easy as using a USB. It supports 16-bit, 24-bit and 32-bit samples, converts sample rates with the highest quality and can convert the sample rates of 2 tracks to the same automatically.  PreSonus AudioBox 22VSL The PreSonus AudioBox 22VSL is a USB audio interface. It has 2 inputs and outputs and a sample rate that can reach up to 96 kHz at a 24-bit quality and low noise figures and background sound. It is quite robust and has a mix control with the computer playback stream for zero-latency therefore you would be able to overdub tracks without experiencing any delay or interference.

Monitoring  Full Range is usually termed, the “main speakers” due to their size and handle with all frequencies from low bass lines to super high frequencies. They are usually used in studios but not very often due to it’s loudness.  Near field are used a lot as alternative speakers in studios however they are 1 st choice when used domestically.  Midfield can be used for quite low frequencies such as 300 Hz to 5kHz. Horn speakers may also be used for midrange frequency. It used mostly in the audio spectrum where most sonic action takes place.  Headphones are mostly used for personal entertainment and listening. They are essential for hearing previous recordings when overdubbing and there are different types of design as well such as the ear types favored by the iPod generation ad the large types usually used in studios. They are also useful for pin pointing faults and mistakes and are ok for mastering and editing however the problem lies with the fact that it wouldn’t be advisable to mix with headphones alone. Monitoring is basically playback however there are different types of monitoring including full range, recording, near field, midfield, amplifiers, headphones and speakers.