Amplitude is the objective measurement of the degree of change in atmospheric pressure caused by sound waves. Sounds with greater amplitude will produce greater changes in atmospheric pressure from high pressure to low pressure.
The wavelength of a wave is the distance between a point on one wave and the same point on the next wave. It is often easiest to measure this from the crest of one wave to the crest of the next wave, but it doesn’t matter where as long as it is the same point in each wave.
The frequency of a wave is the number of waves produced by a source each second. It is also the number of waves that pass a certain point each second. The unit of frequency is the hertz (Hz). It is common for kilohertz (kHz), megahertz (MHz) and gigahertz (GHz) to be used when waves have very high frequencies.
Factors to consider when choosing a microphone:
A shotgun microphone is a directional microphone that must be pointed directly at its target sound source for proper recording. They pick up sound well when the sound source is directly in front of them but begin to pick up the sound worse when the sound source is moved to the sides and rear. A shotgun mic must be aimed or pointed directly at its target source in order to effectively to pick it up.
Topfound Footage Films (2017)
Dynamic microphones are versatile and ideal for general use. They use a simple design with few moving parts and are relatively sturdy and resilient to rough handling. They are also better suited to handling high volume levels, such as from certain musical instruments or amplifiers. They have no internal amplifier and do not require batteries or external power.
Corp, S.T. (2017) SamsonTech
Lavalier (Lapel) Microphone
A lavalier microphone is a small microphone used for television, theatre, and public speaking in order to allow hands-free operation. They are most commonly made with small clips for attaching to collars, ties, or other clothing. The cord may be hidden by clothes and either run to a radio frequency transmitter kept in a pocket or clipped to a belt, or routed directly to the mixer or a recording device.
Lavalier microphones, 2000
We carried out a short task in which we tested just the audio of the microphones we had learned about which included the dynamic, lapel and shotgun mics. We carried out three tests in an inside open space, inside closed space and outside to see how this would effect the sound quality and which mic would work best in each environment. We carried out this test again later on in the week in more detail also using visuals which allowed us to gain a better understanding of each microphone, however this task has allowed me to hear which type of sound each microphone produces.
Final Task – Interview
For this task we tested the use of two different microphones: lapel and shotgun. We used a long shot camera angle to film the clips with the lapel microphone as this microphone can be hidden and would not show up in long shot. For the shotgun microphone however we needed to use a close up shot as this is quite a large microphone and needs to be held close to the subject to produce a good quality sound but cannot be in shot. We tested each microphone in three different locations, an inside open space, an inside closed space and an outside environment. We decided to change the filming location so we would be able to see if the sound would be effected by the external location. We conducted an interview with the different microphones and asked basic college related questions so that the focus would be on the sound quality rather than the interview itself as the audio is what we wanted to learn from. Looking back on the final footage one thing that did not go as planned was the placement of the lapel microphone. Unfortunately in the outside clips the microphone wires are visible to the audience which defeats the point of the lapel microphone as its main feature is that is small and can be hidden. If I was to re do this task I would have placed the recorder inside the subjects pocket and place the wires under her shirt so that they were not visible. Despite this I think the overall sound quality of all the clips came out well and the difference between the mics can be clearly heard. Overall from doing this task I have found that the shotgun microphone will give a much clearer sound quality, however it does pick up other ambient sounds. For example in the first set of clips at the inside closed space the shotgun microphone picks up external sounds of people talking while the lapel microphone does not. It is clear from the footage that the shotgun mic does not work well in an open environment , however it does project the sound of the subjects voice well so if you wanted a clear sound this would be a good microphone to use you would just need to make sure you had a quiet location to film in. I think that the lapel mic worked well in the busier environments as it doesn’t pick up much external sound and being as its placed so closely to the subjects mouth this is the main sound that is picked up.
BBC (2006) GCSE Bitesize: Amplitude, wavelength and frequency. Available at: http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/radiation/anintroductiontowavesrev2.shtml (Accessed: 31 January 2017)
Wavelength (no date) Astro Available at: http://www.astro.cornell.edu/academics/courses/astro201/wavelength.htm (Accessed: 31 January 2017)
Corp, S.T. (2017) SamsonTech. Available at: http://www.samsontech.com/samson/products/microphones/dynamic-microphones/q7/ (Accessed: 31 January 2017).
Lavalier microphones (2000) Available at: https://www.bhphotovideo.com/c/buy/Lavalier/ci/8535/N/4291086006 (Accessed: 31 January 2017)
Topfound Footage Films (2017) http://topfoundfootagefilms.com/rode-ntg-2-condenser-shotgun-microphone-discover-the-sound (Accessed: 31 January 2017)
MediaCollege (no date) Dynamic microphones. Available at: http://www.mediacollege.com/audio/microphones/dynamic.html (Accessed: 17 February 2017).