A pop shield, also known as a "pop screen," is a mesh screen placed between the performer and the microphone. The pop shield prevents loud popping sounds from occurring on plosive consonants like "P" or "B" sounds. Commercially available pop shields can be made of either fabric or metal mesh. If you don't want to buy a pop shield, homemade versions work just as well. Just stretch nylon mesh fabric, such as pantyhose material, over a frame. For the frame, you can use an embroidery hoop or bend a wire hanger into a loop shape.
The first piece of equipment in the vocal signal chain is the microphone. Microphones are transducers. This means that they transform the vocal sound waves into a digital signal, which can then be processed, recorded and edited. When choosing a microphone for a vocalist, be aware that every model of microphone has a specific frequency response --- in other words, the microphone emphasizes some audio frequencies more than others. Because each vocalist's voice is unique, different microphones will sound better with different voices.
Most microphones put out a signal that is too low to be recorded directly. A preamp is a device that boosts the audio signal before it is recorded. When recording directly into a computer's sound card, for example, a preamp is required. In many digital and analog recording systems, preamps are built into the microphone inputs, but you may still prefer to use an external preamp, such as a tube preamp, to add its specific character to the recording.
When used in the recording process, compressors can help reduce variations in vocal amplitude. If, for example, the chorus of a song is sung louder than the verses, a compressor will adjust the signal to smooth out those variations. It is important to use a light hand with compression during the recording process, because when vocals are recorded with compression, it cannot be undone later.