The violin is considered to be a high-pitch instrument and it is the smallest in the violin group. The radiation pattern is very complex and it might require some experimenting with the microphone placement to find the desired sound. The overtones and many fine details of the violin require a microphone that handles high frequencies and has a high-level of accuracy as well.
The spot under the bridge, between the strings and the deck, is a good position to mount a mic. This position represents many of the elements of the violin sound we want to capture – the sound of the soundboard as well as ‘bite’ when the strings are plucked or bowed. This placement can appear to be too “harsh” but offers a unique combination of natural string sound as well as high audio separation onstage.
If you prefer more volume, positioning the mic closer to, or pointing at, the F-hole, is ideal yet this may result in a more “boxy” sound. For more information, read the Mounting the microphone section below.
Types of microphones
Omnidirectional (pressure) microphones have the great advantage of picking up sound evenly from all directions (although some “omnidirectional” microphones are slightly directional at the highest frequencies). Using an omnidirectional microphone is appropriate when you want to pick up the full sound of the instrument and you can maneuver it (using a gooseneck) a short distance away from the instrument.
Using an omnidirectional microphone – like the 4006ES Omnidirectional Microphone or the 4061 Miniature Omnidirectional Microphone – allows you to pick any one place, close to the instrument. If you use a gooseneck, you can place the mic a short distance from the instrument if you prefer. Using an omnidirectional microphone ensures the sound will not lack low-frequency due to the proximity effect as when using directional microphones. Proximity effect is an increase in bass or low-frequency response when a sound source is close to a directional microphone.
Using a directional microphone like the 4099 Instrument Microphone or the 4011ES Cardioid Microphone has the advantage of being able to focus on the sound of the key instrument, isolating it from surrounding sound sources, such as other instruments onstage or the PA system. On the other hand, directional microphones suffer from the proximity effect and therefore require more adjustment to find the preferred position. Moving the microphone close to the instrument will increase the low-end response, which might be desirable.
Bear in mind that the soundboard of even a relatively small violin reacts as a reflective surface. The incoming sound from other sources (instruments, PA system) might reflect off it and enter the microphone from the front even if the microphone is pointing away from the source.