In this chapter I learned about microphone placement help me a lot with and miking different techniques of miking microphone choice and miking specific instruments. The characteristics of microphones can give some indication of mics application and function.
Diaphragm size is key physical factor of microphones is indicative of the frequency response of the microphone. A large diaphragm corresponds to a microphone designed to be responsive at lower frequencies and a smaller diaphragm corresponds to a microphone that will be more responsive at higher frequencies.
The three main type of microphones and how they transduce sound into electrical energy and their inherent mechanical differences cause sound to be captured and colored differently.
Dynamic microphones- work based on electromagnetic principle and feature a stiff, thick diagram wrapped in coil of wire. Changes in sound pressure causes coil to vibrate in a magnetic structure, disrupting the magnetic field.
Condenser microphones- work based on electrostatic principle, using two plates, on stationary (the back), and another that reacts to changes in sound pressure.differences in sound pressure results in voltage differences between plates.
Ribbon microphones- acoustic pressure from the front or back causes vibrations within a thin aluminum diaphragm (the ribbon) placed between two strong magnets. The fragility of the aluminum diagram makes it susceptible to being blown because of loud sound sources or hot plugging (non graph application of phantom power).
Mono Miking techniques:
A real instrument is a blend of infinite number of sounds from all parts of the instrument. You can only capture a part of the instrument if the mic is too close.You can determine the distance based on the primary sound producing element.
Distant microphone placement- the mic should be relatively high and distant from walls to avoid reflections interfering with direct sound. The mic should be placed at least 3 feet from the instrument.
Close microphone placement- involves positioning one or more mics between 1 inch and 3 feet from a sound source.
Accent microphone placement- placing a microphone close to a source that is ultimately mixed with a differently placed mic or mics to improve the tonal balance, as special effect or to add presence.
Ambient microphone placement- involves placing a mic or mics at enough distance from a source where the room sound is more prominent than the direct sound.
Stereo Miking techniques:
Stereo miking essentially means using two mics to record. Be mindful that you may phase issues recording in stereo. The more similar two sounds higher the chances of interferences with each other.
Spaced pair- is used to broadly describe any stereo miking technique whose only hard line specification of usage of two mics.
X-Y – the x-y configuration utilizes two matched cardioid microphones placed with the heads nearly together at 90 degree angles. The resulting pickup will be larger that the pickup pattern of an individual mic.
Blumlein Pair – is almost identical to the X-Y technique with one variation two bi-directional mics are used at 90 degree angles.
ORTF- two cardioid mics are placed with 110 degrees with the heads 17cm apart. With this technique mics placement can be as simple as moving around the room until it sounds good and the placing the mics where your head was.
Mid Side- placing a cardioid mic facing the sound source and the bi-directional mic is placed perpendicular to the cardioid mic.
Decca tree – is used mostly for recording orchestras and large ensembles. The configuration can be achieved with a T- shaped mic stand or using multiple standard stands/ clips.
Miking specific instruments:
Bass Guitar- the best miked sounds are achieved by putting a dynamic mic 7 to 12 inches from the speaker grille and playing normally.
Electric guitar- Like electric guitars, guitars can be sent to a recording console directly with a DI box, but miking the amp usually produces the best results.The sound that you get when you mic an amp is relative to where you place the microphone in relation to the speakers.
Acoustic guitars- have a very wide frequency range and are more delicate and sonically nuanced than their electric counterparts. So you need to use a somewhat sensitive mic with a good high frequency response.position the mic 12-15 inches from the guitar and aim it either at the point where the neck joins the body or at the bridge.
Keyboards- can be plugged directly into the mixer but sometimes miking the amp can produce a warmer sound which can be useful to take the edge off these digital instruments.
Bass drum- you can mic the bass drum through the porthole in the front head, and place folded blanket or feathered pillow inside the shell to provide some damping.
Snare drum- are usually miked with dynamic mics that can handle and capture the sudden transient smack produced by a hard hit snare drum.
Hi-hat- can be easily miked using a small condenser mic placed 2"-3" away angled slightly away from other elements of the kit.
Toms- for a tight and defined Tom sound, mics should be placed a few inches from the Toms.
Overheads- the X/Y configuration captures the stereo image with little chance of facing problems.Even more simply a spaced pair placed over the kit can work.