Understanding Microphone Technology

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Amplify What You Can’t Hear For Yourself

Shotgun Microphones – What are they?

‘Shotgun mic’ is actually a generic term that has come to classify microphones of several types. The ‘shotgun’ mic used to typically be a true condenser (externally powered) long microphone, but has now come to mean almost any long barreled microphone with a narrow acceptance angle. The use of the “Shotgun mic” is considered when sound from a specific location requires amplification and quality in a recording. These microphones are useful when it is difficult to put a microphone in a specific location or device. Like a camcorder. And since a parabolic microphone would cover a larger area, it’s too cumbersome to mount. See the photos below.

These could include various types of mic’s termed by their manufacturers as ‘cardioid’, ‘super cardioid’, and ‘lobar/gun’ as well as several other “creative” terms. In a typical field audio kit, the shotgun mic is typically the sound source for around 50 to 70% of what you hear actually ending up in the final mix for films and television. The reason is that, correctly used, a shotgun microphone will pick up the voices of the talent with a comfortable amount of the surrounding ambient sound. Unlike the sterile, closed mic’d sound that is typical with a lavaliere microphone, the shotgun mic usually exhibits a fuller, richer and more pleasing sound quality. However, it is a mistake to think of a shotgun mic as a magical device that can only selectively pick up a specific sound while totally rejecting all sounds to the side or rear of the microphone. The way sound behaves is more complex than can be explained in this review, but suffice it to say, a shotgun mic is the correct tool for many audio tasks but it is not an all-purpose solution to every audio challenge. The shotgun mic is the logical place to begin in building a high quality field audio package.

Camcorder Mounted

Many owners of sound design/audio post facilities cringe at the phrase, ‘camcorder mounted mic’ but the facts of life are that many DV users do cover live event, documentary type situations, working alone without a sound recordist , and are specifically interested in how well a microphone mounted on their DV camcorder will perform. We tested all three microphones mounted on our Sony TRV-900 DV camcorder with a Beachtek Systems XLR adaptor plate and a Lightwave Systems Universal Mini Mount with a two inch height extension to remove the tip of the mic from the upper portion of the picture. This extension is needed on most of the smaller camcorders but may or may not be necessary on a larger unit like a Canon XL-1 or Sony PD-150.

Boom Mounted

This is the preferred method of working with a shotgun mic and the method used in 90% of all professional work. The advantage is that the shotgun can be brought much closer to the talent or subject’s proximity, thereby resulting in a much better signal to noise ratio, isolating the talent or subject’s sound effectively from unwanted ambient sound while still retaining the richness and superior bass response that a shotgun records as compared to most other types of mics. The downside is that you must use a bigger crew, using the shotgun/boompole with at least with a boom operator/mixer or preferably, with a separate mixer and boom operator. It takes a crew of least two and preferably three to really work well with a single camera and a shotgun/boompole. We tested the microphones using a Lightwave Systems Universal Mini-Mount and Zeppelin mounted on a carbon-fiber Gitzo 11 foot boompole on a variety of shooting situations including informal “run and gun” setups, two camera sit down interviews and Steadicam “walk and talks”. The mics were recorded through a PSC M4MkII four channel field mixer into several camcorders including a Sony TRV-900 using a Beachtek Systems XLR adaptor plate, a Sony DSR-500WS camcorder and a Canon XL-1 camcorder, as well as an HHB MDP-500 Professional Mini Disc recorder.

You’ll Love What You’ve Been Missing

In the Shadows Paranormal Project has had great success with these recording devices and believe we’ve caught sound that we would have otherwise missed. As this is not something many paranormal teams think about, it’s something they should…And not only with camcorders and cameras, but with digital and analog audio recordings. Reel-to-reel would knock your socks off…as you’ll hear everything that goes bump in the night, even that moth flying too close to your head will sound like the Mothman himself.

You’ll want to use one for every investigation, and never again will you use the camcorder without one. Especially when you begin hearing EVPs over your video!

Parabolic Microphones

A parabolic microphone is a microphone that uses a parabolic reflector to collect and focus sound waves onto a receiver, in much the same way that a satellite dish (e.g. – a parabolic antenna) does with radio waves. Typical uses for this microphone today include nature recording, field audio for sports broadcasting (the referee being yelled at by a player for example), eavesdropping, and law enforcement. This unusually focused front sensitivity and can pick up the faintest sounds from many meters away and amplify them. This type of microphone is said to have actually been designed for espionage because of the ability to specify direction as well as amplification.

On the negative side, parabolic microphones are generally not used for standard recording applications because they tend to have poor low-frequency response as a side effect of their design. This is a direct result of the physical laws that govern sound waves.

Parabolas only focus waves with a wavelength much smaller than the diameter of the parabola. Since sound waves travel at 342 m/s (meters per second – the speed of sound) through the air, obtaining hi-fidelity sound (down to 20 Hz, the lower limit of human hearing) would require a parabola with a diameter greater than 17 meters (= 342 m/s / 20 Hz). Most parabolic microphones sacrifice low-end fidelity to get a more manageable size.

Hear a Conversations Upto 300 Yards Away

The DetectEar is the latest in high-end advanced long-range listening devices. This powerful surveillance and investigative tool incorporates a 20-inch diameter snap-together parabolic dish combined with the most advanced audio circuitry available. The DetectEar is also equipped with a 3-band equalizer to adjust for specific sound frequencies, recording jack, and communications input jack for outstanding surveillance capabilities. The DetectEar can be mounted to a tripod for extended use and comes with a hard carrying case for discreet and easy transportation. Powered by only 2 AAA batteries, the DetectEar is your ultimate professional listening device. It’s price you ask??? At $599.99, it’s will normally be way out of reach for the average paranormal investigation group.

The Paranormal Connection

Although it size can be cumbersome, it should be understood that a parabolic microphone is nothing more an ordinary microphone mounted inside a sound-reflecting dish having a parabolic cross-section. As sound waves pass straight into the parabolic reflector they are focused and directed to the microphone; sounds entering the reflector dish from other angles impinge directly on the microphone, but are not focused on it by the reflector. Thus, the parabolic microphone can be highly directional, that is, more sensitive to sound sources at which it is directly pointed than to other sources. This makes the parabolic microphone useful for recording localized sources of relatively faint sounds, such as whispers, conversations, and great for EVP’s (Electronic Voice Phenomena) from a distance. Also a very useful tool for Cryptozoologists & UFOlogists as well. And it’s perfectly suited for long hallways much like those found in Eastern State Penitentiary or Waverly Hills Sanitarium.

Desert Highlands Paranormal Research had purchased a unit second-hand designed for bird watching at a garage sale for less than $50, that normally retails for $199.00 and had hardly been used. So there are deals out there to be had.

The DHPR unit Parabolic Ear Sound System that is exceptionally portable and rugged, featuring a multitude of features making it comparable to more expensive models. The detachable cone is only 12 inches in diameter and constructed of waterproof, shock-proof material. Which increases sound 37 times and, in certain cases depending upon other surrounding noise and wind. We have pick up on conversations at least 400 yards away. The Parabolic Ear, as it’s called, uses a very sensitive microphone with intricate circuitry to amplify sound (do not confuse this unit with cheaper look-a-like toys that are on the market). The sounds are then transmitted to an extremely high-grade amp and then to a pair of Bose headphones that help prevent harmful and unwanted loud sounds or noise from reaching the user’s ears. The dish helps pinpoint and directional sound to reduce background noise background, and records on to our Olympus MP3 Stereo digital recorders or Zoom HD recorder.

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When looking for parabolic microphone, consider these features: Super sound amplification-Focusing on sounds in the direction you point the microphone, automatic shut-off circuit that shuts off sounds over 95 decibel preventing loud sounds from amplification, independent volume control to allow you to select the best amplification level for each ear, output jacks to digital recording devices, 40 hours of continuous use on batteries, wrist straps, accessory elastic bands attach the microphone to your forearm for hands-free operation.

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