A few tips on how to use mics for better pickup
The type and placement of mics can make a big difference in the overall sound. Try these techniques, you may find better results by using one or more of them.
Let’s face it – the field of loudspeaker microphones currently faces several microphone challenges that often threaten sound quality. On the set, the sound from the monitors bleeds into the vocal mic and renders the tone. The bass bleeds into the drum mics, and the drums bleeds into the piano mics. There are other mic-related glitches—the sudden appearance of a breeze, the hum of lighting fixtures, a glitch in a wireless mic, and even an electric shock. So let’s look at trying to solve at least some of these problems. Based on the experience of live mixers, technicians, and operators, these recommendations will help control feedback and leakage, and help deliver a clear, natural sound to the listener.
Close to the source
The first trick is to try to get the source close to the directional microphone. To start, place each microphone within a few inches of its sound source. Picking up close range will increase the volume of the microphone, making the sound system louder. Use unidirectional microphones to reduce feedback and crosstalk. They isolate the sound to the side and rear of the microphone, such as floor monitors. Typical unidirectional types are cardioid, supercardioid and superdirectional.
Sometimes it helps to place the mic exactly at the sound source
Most directional mics will add bass as your mic gets closer. This is the so-called proximity effect. At low frequencies it provides natural gain (extra volume with no feedback). By the way, the excess bass is cut (reduced) through the mixer’s EQ to reduce the low frequency crosstalk picked up by the mic.
Next, here’s an extreme way to get the mic loudest: place the mic where the acoustic instrument is loudest. Some typical locations are near the sound hole of a guitar, the mouth of a saxophone, or inside the shell of a tambourine. Use this method as a last resort, as close-up radios tend to render the timbre, resulting in an unnatural sound.
Here’s why: most instruments are designed to sound their best at a certain distance (1.5 feet or more). Thus, placing a flat-response mic there will pick up a natural or balanced tone. But when approached, the local sound of the instrument is accentuated. Voices picked up very close may not represent the timbre of the entire instrument.
This position is likely to accentuate the low-end resonance
For example, the soundhole of a guitar will resonate strongly between 80Hz and 100Hz. Placing the mic too close to the sound hole will hear and accentuate the low frequency response, producing bass boost and hum that is not present when the mic is placed farther away. .
Microphones at close range are also harsh. To make the guitar sound more natural when the mic is close to the sound hole, attenuate the extra bass on the mixer, or use a mic with a low cut. Also attenuate 3KHz to reduce harshness.
The microphone placed on the saxophone mouth resembles a kazoo. To make it sound soft, attenuate about 3KHz and add about 300Hz. And if you can get enough pre-feedback gain at the position of the microphone, the sound will be more natural, and use all methods to achieve this effect.
Contact
Another method is to use a contact pickup. Contact pickups solve the feedback problem because they are sensitive to mechanical vibrations, not sound waves. Pickups for guitars usually sound good when placed near or below the bridge. Unfortunately, a guitar with a pickup sounds shocking because it ignores the strings. Many sound operators have had success with a hybrid approach combining pickups and small mics. Place the pickups under the bridge to pick up the bass and provide volume and punch. Small supercardioid microphones only need to be installed in the opposite sound holes. It will provide high notes and clear strings. Pickups and microphones are mixed in a small two-input mixer. The combination of pickup and mic provides a loud, powerful, natural sound with all the crispness of a real guitar.
Sending only the pickup signal to the stage returns, and only sending the mic signal to the PA speakers will help reduce howling. Minimizing the number of microphones as much as possible also helps. The more microphones are used, the more likely it will be howling. Double the number of open mics and reduce gain before feedback by 3dB. Two mics at the same gain will have 3dB less gain before feedback than one mic; four mics will have 3dB less gain before feedback than two mics, etc.
Reduce the number of open microphones and turn off all microphones that are not in use at the moment. You’d probably prefer to drop them down to about 12dB rather than turn them off so you don’t miss the signal. Instead of using 10 mics on one drum, try using a tiny omni mic in the center of the drum set. Small mics are recommended because they have an excellent high frequency in all different directions, unlike larger mics. Clip the mic to the right of the snare drum rim, about four inches above the drum, near the center of the drum. It will pick up all the toms and cymbals around. You’ll be amazed how good a microphone can sound. Adding bass makes it fuller. If the cymbals are too weak, lower them a few inches. Hang another small mic on the kick drum and it will sound full, as omni-directional condenser mics have a deep bass response regardless of their size. The disadvantage of this method is that the balance of the entire drum set cannot be controlled, except for the placement of the microphone.
Try using DI boxes instead of mics on electric guitars and basses. The DI box pickup is free of feedback and crosstalk, and can be plugged directly into the interface under the musician’s effects. This approach, after all, ignores guitar amp distortion, which is often an important part of the sound.
Cancel Distance
Finally, try a noise-cancelling mic. Noise-cancelling microphones are acoustically designed to cancel some sounds that are far away, such as musical instruments on stage or monitor speakers. This microphone provides excellent gain before feedback and is almost completely isolated.
Differential microphones are designed to cancel sounds more than a few inches away, such as musical instruments on stage. As a result, many users have reported that their room mixers have been greatly improved because the microphones are almost completely independent. In other words, “Mic1” is no longer a vocal, some drums, guitar and bass. “Mic1” contains vocals only. Singers using differential mics must lip to the mic’s grid; otherwise, their voices are canceled. This limitation is not a problem, as many singers have already kissed the microphone. But if the singer likes to control the singing effect by using the distance of the microphone, this can be a disadvantage.
Try these techniques, you may find better results by using one or more of them.
