The sampling rate you should use will depend on the final output. For example, if recording for a CD production, record at 44,100 sampling rate and 16 bits; however, if recording for DVD production, record at 48,000 sampling rate and 24 bits. Should the final production output not be known at the time of recording then we recommend recording at the higher sampling and bit rate which will allow for down-sampling later if needed. It is better to have to down-sample than up-sample because of possible aliasing problems.
Vernacular Media Productions (VMP) used to recommend a bit rate of 16 bits, but with new computers drive space is not the problem that it once was. So record at the higher sample and bit rate unless you have limited storage space; then you might want to consider recording at the 16 bit rate. VMP now recommends recording at 32 bit rate when available or the highest your device will allow.
When recording in settings other than a professional studio there may be external noise which can distract from the final results. Padding in the studio can help eliminate some of the noise, but microphone placement is also important for helping to eliminating external sounds.
The key to getting good sound in a noisy environment is to close-mic with a unidirectional microphone. By doing this the input volume control can be kept low, preventing external sounds from being recorded. However, close microphoning has two problems that can affect the recording: proximity effect and breath noise.
Unwanted external noise can be eliminated or reduced by placing the microphone within a few inches of the talent’s mouth. The disadvantage of this is the proximity effect, which increases the bass sound of the voice. Generally this is acceptable, but it is important to remember the position of the microphone in relation to the talent during previous recording sessions with the same talent. Different positions and spacing produce different sounds, which are very noticeable in the recording.
When a microphone is positioned directly in front of the talent’s mouth, there is a good possibility breath noise will reach the microphone and be included in the recording. These can be reduced or eliminated by positioning the microphone at a 45º degree angle above and off to the side.
A type of breath noise is a pop, which is an explosive breath sound produced when a puff of air from the mouth strikes the microphone. This is usually from pronouncing the letters “p”, “t” and “b”. A pop filter, which is a metal grill or foam cover over the front of the microphone, helps to reduce the popping sounds.