A guide to choosing the right microphone
Embracing the selection process
Choosing the correct microphone for the required application can be a stressful experience and there are so many variables to consider. The use of microphones, types and brands can be a very subjective experience so it’s often difficult to know that you’ve made the right choice. I always say that you need to embrace the process of selecting microphones – treating it like an experience – and in most cases it is an enjoyable exercise to experiment with different products and techniques to achieve the sound you want.
Let’s take a deeper look at the options available and their intended use in audio services.
We can start with the most subjective element: the vocal microphone. As all voice artists/singers have different tones and voice characteristics, choosing the correct microphone could be the difference between a good end product and a sub-standard result. Every voice is going to sound different through each microphone and it’s important to look for particular features and how they suit your needs.
Here’s a list for you to consider:
- Frequency response: This is important, depending on the timbre of the voice.
- Proximity effect: This is particularly important to consider and can make a big difference to how the microphone translates the vocals. If the vocalist is too far away from the microphone the sound may be too thin, causing the gain to be boosted and possibly resulting in feedback issues. If the vocalist sings closer to the microphone it allows the sound engineer to adjust the gain properly, EQ the channel properly and get the desired tone for that environment
- Handling noise(when the microphone is held): It is always advised to make use of a microphone that is not physically handled by the voice artist and rather supported by a shock mount to ensure that the microphone is stable and secure. If the singer is holding the microphone, you want a microphone that will not transfer the handling noise as much (some are better than others, of course).
- SPL handling: If the vocalist has a powerful voice, you don’t want to end up with a microphone that is ultra-sensitive as you may risk distorting the sound at the microphone. If a microphone is chosen that has a higher SPL handling, then no distortion will occur and the sound engineer will have better control over the signal.
Dynamic vs. Condenser Microphones
Condenser microphones have a much higher sensitivity level and often have a broader frequency response as a result. Depending on the environment and the microphone chosen, a condenser microphone may be too sensitive and only cause feedback problems. In this scenario it might be better to consider a dynamic microphone.
Dynamic microphones are typically less sensitive, better rounded in tone and because they have a smaller proximity effect than condensers, would result in having to sing right on top of the microphone to achieve the best signal quality and level.
It is important to consider these basic principles and apply them to anything you are using a microphone for.
Let’s take a look at mic’ing a guitar amplifier. There are various techniques based on where to point the microphone in relation to the speaker cone. If it’s an open back guitar cabinet, you could put one microphone on the front and one on the back and then flip the phase on one of them to achieve a ‘fatter’ sound. In the right environment you could use a condenser microphone on a guitar amp. There is typically enough gain off of the front of the cabinet that you don’t have to boost the gain on the microphone. Be sure it can handle the SPL level coming out of the cabinet, though. You could double up the microphones on a guitar cabinet by using one condenser and one dynamic to achieve two distinct tones to mix.
As you can see, there is lots of room to experiment and play around to find the correct application for your microphone.
Principles for Selecting Microphones
Considering the above, it is quite evident that choosing a microphone is not as straight forward as plugging a microphone in and starting recording. There are always factors to consider prior to your recording session and it’s important to think them through beforehand.
If you have the ability to borrow, rent or buy different microphones to try out, this will give you a chance to really A/B test the different performance qualities of each one. When you do so, take notes. You may find that the quality of one microphone that may not be suitable for one application, may turn out to be perfect for another.