Frequency Response Charts and Microphones

Sound in Hertz Sound is measured in Hertz(Hz) and is referred to as frequencies. The human ear can hear 20Hz to 20000Hz (20kHz – 20 kilohertz). For example the A note that all instruments tune to in the orchestra is measured as 440Hz. The example below is a digital image of what sound looks like. As the Hertz increases (pitch goes higher) the waves get smaller and smaller.

Frequency Response Chart To choose the perfect microphone to record your instrument, you have to look at the frequency response chart. The bass frequencies encompasses 20Hz-500Hz. Midrange frequencies would be 500Hz to 5,000Hz, and high frequencies would be 5,000Hz-20kHz. These frequencies match the ones that are in your EQ on your phones or iPod – Bass, mids or treble. dB SPL – Decibel sound pressure level. This means how loud the sound is, the higher number the louder the sound. Low Mids Highs

What does this frequency response chart say? The frequency response chart demonstrates: The low frequencies gradually decrease and increase between dB. The mids increase greatly to nearly 40dB above the lowest frequency. The highs decrease rapidly to 80 dB then slightly increase to 85 dB. Low Mids Highs

Frequency Response Charts Look at the following two Frequency Response Charts and explain each graph in regards to bass, mids and highs. Write your answer in your book.

Frequency Response Charts The reason the frequency response charts are important in recording because each microphone has its own ‘characteristics’ and this can change the sound of the instrument being recorded. Take the acoustic guitar for instance, the type of microphone to record this would be a small diaphragm condenser microphone that has a frequency response that has increased mids and highs. This will make the guitar to sound bright and capture the strumming sound. For a bass drum, your would use a dynamic microphone that has a frequency response that has increased bass and highs so the bass drum would boom from the increased bass and you would captured the kick hitting the skin of the drum through the increased highs. The best way to choose the right microphone for your instrument being recorded is to experiment, try multiple microphones and choose the best one for the sound desired.

Microphone There are two different types of microphones: dynamic and condenser. Dynamic microphones can handle high SPL (loud volume) when recording. The microphones are usually robust and inexpensive. There are two types of condenser microphones; small and large diaphragm condenser microphones. All condenser microphones can not handle high SPL like drums and are not very robust – drop them once and they never work well again. Condenser microphones give a very clear and definite sound.

Microphones The microphones the school offers to record are as follows: Shure sm58 x 2 Shure sm57 x 1 Shure PG 52 x 1 Behringer C2 x 2 Behringer XM1800S Senheisser e815S x 2 AKG D310 x 1 Audio Technica 2020

Microphones Using the list of microphones on the other slide, look up each microphone to know what they look like and research each microphone and list what instrument is used to record. Write your answers in your book.