The effects of holding positions on the frequency response of dynamic vocal microphones

Abstract

This study examines the effects of different holding positions of the microphone body and capsule on the frequency response of dynamic vocal microphones. Microphones enable the amplification and recording of sound by converting sound waves into electrical signals. Based on their operating principles, microphones are divided into two primary types: electromagnetic and electrostatic. The sample for this study consists of dynamic microphones, which fall under the category of electromagnetic microphones. Dynamic microphones are commonly preferred in live performances and studio recordings due to their durability, affordability, and low self-noise levels. In this study, the effects of various grip positions on frequency response were analyzed using the Shure SM-58 model dynamic microphone, which is widely used in both studio and live sound environments. The selected grip positions include the standard stand position, fully enclosed capsule grip, semi-open capsule grip, and body grip. These positions comprise the sample for the study. The research was conducted in a controlled studio environment, isolated from external factors and with appropriate acoustic conditions. Audio samples were collected by having a professional vocalist sing the G4 note (392 Hz) on the syllable “na” for 5 seconds. The recordings, conducted at an industry- standard 96 kHz sampling rate and 24-bit resolution, were repeated for each grip position and digitally transferred as .wav files. The .wav files were normalized in Audacity in preparation for Fast Fourier Transform (FFT) analysis. During the data analysis process, the normalized .wav files were analyzed via FFT implemented in Python. The data were examined by analyzing the first seven harmonics within three octaves above the G4 note (392 Hz). Referring to the standard stand position, the Fully Closed Grip Position on the Capsule exhibited a significant reduction in lower frequencies alongside an increase in upper frequencies. Similarly, the Capsule Half-Open Grip Position resulted in decreased low and mid frequencies, with a corresponding rise in high frequencies. Observations from the Microphone Body Grip Position also indicated a decrease in lower frequencies and an enhancement in upper frequency regions. Based on these findings, this study aims to provide vocal performers, recording engineers, and researchers in music technology with insights into achieving higher precision and professionalism by understanding how appropriate microphone holding techniques influence the sound’s balance.

Keywords

• dynamic microphones
• frequency analysis
• frequency response
• microphone holding positions

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