Many devices and accessories are available to improve the sound of recordings made with microphones, such as isolation shields, pop filters, and windshields. However, not all of them are highly effective.
Do microphone isolation shields work? By absorbing the sound waves projected past the microphone capsule, isolation shields help to deaden the sound and prevent reflections from being recorded. This results in clearer recordings that are generally much easier to mix.
Microphone isolation shields are an affordable and easy way to improve the sound of your recordings. They’re particularly useful when using a condenser microphone, as the sensitivity of these mics often leads to sound reflections being picked up.
In this detailed guide, we’ll explain why microphone isolation shields are worth adding to your recording setup, which are the best types, and how you can use them most effectively.
How Do Microphone Isolation Shields Work?
Microphone isolation shields are useful tools for musicians, podcasters, or voiceover artists. If you’ve recorded vocals before, you’ve probably experienced the issues that sound reflections can cause.
When someone sings or talks into a microphone, some of the sounds are picked up by the capsule as it comes out of the person’s mouth. The sound is also projected around and past the microphone.
These sound waves can then bounce off the walls and surfaces in the room and be reflected into the microphone capsule after the first sound waves have been captured. This can cause an undesirable effect which makes vocal recordings less clear and more difficult to mix.
Isolation shields are a capable solution to this problem. They’re commonly made from an acoustic foam material that is attached to a slightly angled surface that covers the back side of the microphone and the surrounding areas.
This foam material absorbs the sound vibrations after they’ve moved past the microphone capsule, which prevents them from being free to move around the room and reflect off the surfaces.
The principle of sound isolation shields is very similar to acoustic panels, which are also made from high-density materials that can absorb sound waves, stopping them from bouncing around the room. The difference is that isolation shields are solely for one microphone rather than the holistic treatment of a studio.
There are many different sound isolation shields available, some of which are more effective than others. The key is to choose one that suits the type of microphone you’re using, which we’ll discuss in more detail later in this guide.
As long as the shield is large enough to cover a substantial area directly behind the microphone, it will provide you with at least some absorption of sound vibrations and thus be a beneficial addition to your setup.
Can Isolation Shields Improve Recordings?
It’s difficult to say whether any piece of equipment or device can improve your recordings because this is ultimately subjective. However, we can definitively say that isolation shields will make your recordings sound clearer and minimize ambient room sounds.
In some cases, you may want to use the ambient sounds of a room in your recordings. This is essentially what reverb is, and some rooms have great-sounding reverberations that can be interesting when used in recordings.
In the modern digital era of audio recordings, most people like to add their reverb as an effect in the mixing process rather than trying to create it naturally when recording. This is because it’s much easier to control the way that reverb sounds when you add it in a DAW and tweak the various settings and parameters.
Isolation shields will help you to achieve cleaner recordings that don’t include as much reverb, ambiance, and reflections. If this is what you’re hoping to achieve, then yes – they certainly can improve your recordings.
Not all isolation shields are equally capable of doing this, though. As we covered earlier, the size of the shield will have a significant impact on its effectiveness, mainly because the more surface area that is covered by the material, the more sound waves are likely to be absorbed.
Another variable is the type of material that is used. Dense foam that is specifically for acoustic treatment is the best choice, but some isolation shields may use thinner layers of foam or some other soft material that won’t be as absorbent.
In addition to absorbing the sound vibrations, so that they can’t re-enter the microphone capsule, isolation shields also improve your recordings in another way.
The shield covers the entire back side of the capsule so that any sounds from the rear will be deflected around it and won’t be picked up as prominently on the recordings you make.
If, for example, you’re recording with a sensitive condenser microphone and someone makes a sound on the other side of the room, the shield will prevent this sound from entering the mic capsule by forming a barrier.
Lowering the chance of background noise being picked up by the microphone means that you won’t need to use tools like EQ or noise gates when mixing to remove them from the final recording.
How to Set Up a Microphone Isolation Shield
The best way to set up a mic isolation shield depends on the design of the specific device you’re using, but generally, there are two ways that this is done.
Firstly, some isolation shields are placed on a separate mic stand to the microphone, and then that stand is positioned behind the mic. The shield may be attached via a clip or mechanism to grip the stand.
Other isolation shields can be placed on a flat surface around the microphone’s back side rather than mounted to a stand. These are better suited to desktop microphones commonly used for podcasts or content creation.
Most singers like to record vocals standing up, as this is considered the best position for breath control and engaging the diaphragm. Therefore, it’s recommendable to use an isolation shield that can be mounted to a mic stand or boom arm for this purpose.
Once the isolation shield has been secured in place, you then need to check that it is covering the back side of the capsule as much as possible. It should be placed close to the microphone grille without touching it.
If the shield touches the mic stand, then this will cause the noise to be picked up in your vocal recordings. Placing it around two inches from the microphone will ensure that even if the stand moves slightly, it won’t come into contact with the grille of the microphone.
Other Ways to Improve Microphone Recordings
Along with using an isolation shield, there are several other easy methods you can use to improve the sound of the recordings you make with your microphone. Combining these devices and techniques will help you to get a better sound quality in your music, podcasts, or other content.
The first and probably most popular way to improve vocal recordings is by employing a pop filter. These simple devices consist of a small surface placed in front of the microphone and have a mesh layer with tiny gaps.
The vocalist then speaks or sings into the pop filter, and any plosive that they produce are captured by the mesh material and deadened before they reach the microphone and cause a “pop” sound in the recordings.
Plosives can be problematic when recording vocals because the popping sounds are difficult to remove or make less noticeable through mixing. It’s therefore best to address the problem beforehand so that your recordings sound cleaner.
Another straightforward way to improve recordings is by using a windshield, but this is really only relevant if you record outdoors. Many content creators these days record audio in different settings, so having a windshield could be beneficial.
These devices work similarly to isolation shields, but they’re often larger so that they can cover a larger area around the microphone capsule.
Wind noise can completely ruin a recording, so preventing it by shielding the microphone with a layer of solid material is a good idea. However, it’s not usually necessary indoors.
Isolation shields are better for indoor recordings, and wind shields are better for outside. Pop filters, on the other hand, should be used for any vocal recordings whether indoors or outdoors.
What is a reflection filter?
A reflection filter is another term to describe a microphone isolation shield. It prevents the sound from reflecting against the walls and surfaces in a room and then entering the capsule during recording.
How do I reduce static on my mic?
You may need to turn down the gain if you’re getting lots of static noise from your microphone. If this doesn’t work, check your microphone cable to see whether a faulty connector or poor shielding is causing interference.
Why do condenser microphones pick up background noise?
The main reason that condenser microphones are prone to picking up a lot of background noise is that they are extremely sensitive. This means that with minimal gain, the microphones record with a lot of detail.