Microphones are essential gadgets used when recording audio. Choosing between the two can be an uphill task, especially when you lack background knowledge in music and production. There is no need to panic because this article will enlighten you with relevant information to improve your understanding of microphones.
The quality of sound captured varies depending on the type of microphone that is being used. For this reason, you need to understand some of the existing differences between the Omnidirectional and Unidirectional microphone when planning to start your production.
This implies that microphones pick their sound from either the front or all directions (Polar pattern mic). This article will highlight differences between Omnidirectional and Unidirectional microphone which will equip you with the knowledge to make informed choices when planning to acquire one.
What is an Omnidirectional Microphone?
Omnidirectional microphones capture sound from all directions making them more flexible when using. In fact, “Omni” in Latin means “all.” These microphones tend to capture sound from all directions without any alterations, making them more efficient when using.
An omnidirectional microphone is commonly used when groups participate in singing, or multiple instruments are being used simultaneously. The gadget can be placed at the center and will capture all sound with equal strength.
What is a Unidirectional Microphone?
Also referred to as the cardioid mic, the Unidirectional mic captures the source’s sound and very little from the sides. No sound is attracted from the back. Therefore, one may require skills when using this particular type of microphone.
Omnidirectional vs. Unidirectional Microphones
In television and concerts, an omnidirectional microphone is highly preferred because of its ability to capture sound from multiple directions.
This validates our earlier point that an omnidirectional microphone gets its signal from all angles. Besides, a unidirectional can only pic 50% or less sound from coming from other directions. Below are some of the standard features to understand the existing differences between the Omnidirectional microphone and the unidirectional.
In a production setup where the sound is supposed to be captured from multiple individuals, an omnidirectional mic may not be the best choice.
“Leakage” may be experienced, and for this reason, using a unidirectional microphone would be the ideal choice. However, using an omnidirectional mic would enhance the performance because of less wind noise, handling, vibration, and popping. Another exciting aspect of the Omni type of microphone is that it can record from the right side up and upside down.
As opposed to the unidirectional microphone, the omnidirectional mic tends to be less precise in channel separation as it picks sound from different directions. Therefore, if channel separation is a factor when considering a microphone, an omnidirectional type would be unfavorable because of the low ratio between the direct and indirect sound.
Conversely, the Omni works perfectly when used at a closer range without the proximity effect associated with a unidirectional microphone. This implies that if the Omni and the unidirectional mics are placed at different distances, the ratio between the two’s direct and indirect sound will remain the same.
This particular attribute is often associated with the producer’s/engineers experience and the microphone’s quality when using live sound applications. Most Omnis tend to feedback at bass or lower mid-range than the omnidirectional mics that give feedback at higher frequencies.
Interestingly, how feedback builds up may vary between the two. First, the Omnis tend to give feedback in a slow manner, which directs directional feedback unexpectedly or suddenly.
Besides, Omni tends to be more effective, especially during the performance, because of its ability to adjust to gain an unbroken gain-to-feedback ratio. For example, in musical performances, this would work correctly since artists can move across the stage without stepping back into the feedback zone.
The Cardioid mic (the directional microphone is often used) has a coverage angle of not less than 130° with a directional response, just as its name implies. The directional mic may have a better response on-axis than on the off-axis. Besides, directional microphones may have an inadequate off-axis response at some point.
This implies that the sound that is captured by the mic from the other side may be weak and not intensely colored, often referred to as “the curtain effect.” To attain authentic sound in the overall production, be sure to use the directional/Cardioid on a clean off-axis. The DPA directional types are likely to take care of the situation, making it more authentic and clean.
This is another disadvantage of directional microphones, especially when working with a high SPL at a close miking. Therefore, the level of distortion needs to be looked upon when choosing the type of microphone. The distortion difference can be easily tested between the directional and the omnidirectional when comparing the THD specifications in DPA’s product range. It would help if you only used directional microphones when the distortion level is low.
Wind-and pop-noises; This particular issue is associated with the directional microphones because of their inbuilt compliant diaphragms. They are subtle to pop and wind noises compared to the omnidirectional type of microphone. The omnidirectional microphones are built with stainless steel, which makes them less compliant.
When Should you Use an Omnidirectional or a Unidirectional Microphone?
Omnidirectional mics are mostly used in professional setups, whereby they are intended to bring a sense of liveliness to the whole recording.
Omnidirectional mics work when:
- Recording sound in a closed room
- Recording a comprehensive source of the sound.
- Recording in a particular target
- Recording in stereo
On the other hand, a unidirectional mic is ideal for live recordings and vocal applications. They work efficiently when the environment for recording is audible.
Unidirectional work entirely when:
- Conducting live performances
- Detecting sound well in untreated rooms.
- Miking up a drum kit.
The insights above clearly show the differences in terms of performance between the omnidirectional and the unidirectional microphone. We conclude that in miking positions, you should always consider the DPA Omni type. Besides, we insist that you always try the Omni first because it offers natural sound and can withstand the high-pressure levels associated with sound. Finally, it is not sensitive to wind, handling, and pop noise and is not affected by proximity.