Presentation on theme: "Dynamic Microphones A microphone’s job is to turn acoustic energy (vibrations in the air) in to an analogue electrical signal which a mixer can understand."— Presentation transcript:
Dynamic Microphones A microphone’s job is to turn acoustic energy (vibrations in the air) in to an analogue electrical signal which a mixer can understand. HOW THEY WORK Diaphragm, a voice coil and a magnet. The voice coil is attached to the diaphragm. Sound sets the diaphragm into motion, the voice coil moves in the magnetic field which creates the audio signal. Rugged & Versatile – throw them around without worrying about breaking or distorting.. Can handle a lot of volume (SPL) Do not need phantom power. Commonly used for live performances / speeches. Great for loud voice and loud instruments – Drums / Amplifiers etc. Do not give the most accurate description of the sound – the thick diaphragm takes longer to respond. Cheap and cheerful – under £100 MOST COMMON DYMANIC MICROPHONE? SHURE SM58 & SHURE SM57
Condenser Microphones HOW THEY WORK! Diaphragm and an electric charged back plate. Sound sets the diaphragm in motion, this changes the electrical field which creates the audio signal. Condenser microphones need power to work! – This comes from the mixer or the pre-amp and is called PHANTOM POWER, or +48V Large or Small Diaphragm ? Condenser microphones come in two categories, Large and Small Diaphragm. Large Diaphragm are more popular – Why? Because they have a more pronounced bottom end. Also large Diaphragm mics possess less self noise (noise created by the mic). Small Diaphragm condenser mics have an even frequency response and more accurately capture high frequency instruments – Violins / Drum Cymbals etc. Most popular style of microphone for studio settings. Very accurate / great clarity / Very well rounded Sound very natural Fast response Needs phantom power (battery) Very sensitive – be careful with gain input or SPL as you do not want to damage the diaphragm. More Expensive - £500+ range. MOST COMMON CONDENSER MICROPHONE? AKG C414 & NEUMANN U87
Ribbon Microphones HOW THEY WORK! Diaphragm and a magnet. A ribbon microphone is a type of dynamic microphone. The vibrations in the air move the diaphgram in the magnetic field which transfers this energy to an audio signal. Ribbon mic’s were very popular in the 30’s / 60’s. They are very fragile and expensive. The most common Ribbon microphones today are manufactured by RCA.
POLAR PATTERNS Microphones pick up sound in different ways. These are known as “Polarity Patterns” or “Polar Patterns”. These are the 3 most common polar patterns. Omnidirectional – capture sounds all around them Cardioid – Captures sound just in front of them Figure 8 – Capture sound from both front and back. Below you can see the pickups pattern of an omnidirectional mic.
POLAR PATTERNS Here you can see the pickup pattern of a figure 8 mic. Here you can see the pickup pattern of a cardioid mic.
POLAR PATTERNS Hyper-Cardioid Compared to a Cardioid pattern, a hyper- cardioid microphone has a tighter area of front sensitivity plus a small area of rear sensitivity. A hyper-cardioid microphone is not unlike a bi-directional, but with a larger area of concentration in the front and a smaller area in the back. Super-Cardioid A super-cardioid pattern is similar to a hyper-cardioid, with a slightly larger area of concentration in the front and a thinner area in the rear.
PHASING Phasing occurs when you are using multiple microphones to record the same instrument. If your microphones are not placed correctly, certain frequencies will drop out. This is known as phase cancellation. TIP 1: Adhere to the 3:1 rule – This simply means that if you have one microphone 1 foot away from the sound source, you’re next microphone needs to be 3 feet away from the sound source. Its simple and it works. The only way to monitor phasing is to record a snippet of the song, play and it back and listen. If any frequencies drop out then you need to adjust your microphones. Waveforms hit microphones at different times. Waveforms at polar opposites will cancel one another out. OUT OF PHASE IN PHASE Waveforms hit microphones at the same time Waveforms at a perfect match.
FURTHER RESEARCH & HELPFUL INFORMATION Polar Patterns - basics/microphone_polar_patterns Microphones – Sensitivity – Mic Techniques– Phasing –