When you are making the effort to record any kind of audio, such as music or a podcast, you want to make sure you have the best possible sound quality. However, that being said, like with anything, you are likely to run into issues with audio. One of the common issues you may come across is microphone bleed. So, what causes this issue, and how can you fix it?
Microphone bleed is something you can encounter when your microphone picks up sound that is other than the source you want to capture. There are many possible causes of this, such as drum kits and headphones. However, there are ways you can tackle this issue with the microphone capturing other sound.
If you are repeatedly facing the issue of microphone bleed, and want to understand it, this is the right article for you! We will explore what microphone bleed is, what causes it, and how you can reduce microphone bleed in your recordings.
What Is Microphone Bleed?
When we think about microphone bleed, the best way to understand this is to think of it as the microphone picking up sounds from sources you do not intend to capture. Therefore, the sound can become muddled with a lot of other external sources. One thing to consider is that microphone bleed is not about the other kinds of noise that can creep in.
For example, if you are recording an audio, the microphone bleed does not refer to the electromagnetic interference that can happen, or even sounds that can come from handling the mic. This is specifically sound that comes in from other sound sources that are disrupting the primary source you intend to capture with the microphone.
When you have microphones that aim to capture sound in a room, you will not get microphone bleed. However, when you set up spot mics on the other hand, you may get some bleeding happening when the environment is not soundproof. Let’s try and understand what the common sources of microphone bleed are in the next few passages.
In most cases, the kind of microphone bleed you will encounter will be headphone bleed. This is what happens when the sound from the headphones enters the microphones. One of the most common places where this is likely to happen is when a vocalist is recording music, and the sound of the track in their headphone mixes in with their vocals.
So what can you do in this case? The vocalist definitely needs headphones to be able to sing at the right time and place. But to understand what to do, let’s look at how this happens in the first place. For one this will happen when the volume is too loud or the signal is too strong.
This can also be the case when your headphones signals are up too high, or if the settings on the microphone are not right, for example the gain is too high. Using low quality headphones can also be a reason that you will have more sound escaping, so one of the ways to reduce this issue is to use higher-quality closed headphones to minimize sound.
Sometimes, when the vocalist is being quiet, you can also run into this issue. That is because this prompts the microphone to become more sensitive to the sounds in your environment. As a result, it may end up picking more sound than necessary.
Most instruments will also cause some kind of sound bleeding issue. In most cases, dealing with instrument bleeds is a relatively straightforward issue, and can be resolved with a little bit of distance. However, drums are one instrument that can cause serious issues. While moving instruments away is helpful, it does disrupt the natural flow of music production.
Drum Kit Bleed
Drum kit bleeds are very common because it is not easy to record this instrument. In most cases, the problem becomes even more pronounced when you are trying to use a mic with each one of the drums. Since all of the drums are so close, and because they are loud, there is a potential for sound waves to travel and for the sound to become mixed up.
This is why when artists are recording, they typically will already expect that mic from the drum kit will bleed. This is quite a conundrum for recording purposes, and ultimately what a lot of artists will do is to avoid close mics for each drum entirely. Instead, it is more common to opt for an overhead, kick, and snare mic, and to mute some mics unless they are used.
How To Prevent Microphone Bleed
Now that you are aware of what microphone bleeds are, and what the common causes of this issue can be, let’s talk prevention! We all know that no one wants to get unwanted sound sources mixed in with their instrumental or vocal recording. Here are some of the steps you can take to prevent or reduce microphone bleeds in the studio.
Lower Headphone Volume And EQ
If you are trying to get to the bottom of the issue and it is a headphone bleed, the easiest way to make things happen is to lower the volume of the device. Once the volume is down, the sound from the headphones will come down as well, and that can no longer be picked up. You can also use EQ to achieve better monitoring without taking down the volume.
As a result, you can get the headphone bleed down to minimal, without having to make the vocalist struggle to engage with the music or track.Another thing you can try is to lower the EQ so it is compatible with where the frequency of the microphone is a lot more sensitive. As a result, the microphone will not be able to pick up the sound from the headphones.
There is a balance you need to maintain here, between low EQ but good quality sound in the headphones so the artist can still have access to a recording that is high in quality. You can try adjusting levels until you reach a solid point where you can get the best of both worlds.
Use Headphones That Are Closed Back
When you look at a lot of professional headphones, especially those used in the recording context, you will notice they are usually closed back. This helps to keep the sound from the outside out, while not allowing the sound from the headphones to escape. As a result, you will be able to avoid having your mic pick up sound from the headphones.
Choosing a good quality headphone set in general is the best call to get rid of microphone bleeding issues. The better quality devices will already be built with recording in mind, so you are less likely to confront problems like this while working.
Use Strategic Placement For Instruments
When you are in the recording studio and have to mic a lot of instruments, you will definitely have to be mindful to avoid bleeding. However, you can prevent this by being strategic in how you place the instruments. The best course of action is to have enough distance between instruments so there is a smaller chance of the sound waves getting mixed up.
If you have the resources and space, you can also place all of the instruments in separate booths and use headphones to keep the artists playing them on rhythm and beat. While this is the best strategy, it does come in the way of authentic interaction between musicians and can result in a low-energy flow in the music you record.
One situation where this may be easy to avoid is with electric instruments, which can be amplified in other booths. The good thing about this strategy is that the musicians can play in the same room so they can play off the energy the environment produces. A go-bo can also be used, which is a panel you can place between instruments to avoid bleeding.
Place And Use Directional Microphones
If you really want to get an isolated recording of a source of sound, the best way to make this happen is to use a directional microphone. These pics have a null point at the back, or they have sensitivity that you can adjust. Therefore, you can point them either towards a direction, or a frequency of sound that matches their settings.
These mics will need to be placed a little bit further away from the louder instruments, such as the drums. Ultimately carefully planning how the instruments, people, and mics are going to be placed in the studio space can really help you capture sound in a more effective manner.
Manual Muting Of Mics
If none of the other tips in this article are working, you also have the opportunity to use a manual method of muting the mic when necessary to eliminate bleeding. While this is difficult to achieve with instruments that will mainly be featured in the sound, you can do it with other instruments. For example, certain parts of the drums that only show up at set times.
Another option you can consider is to edit the sound later in the process. While this may be a more difficult way to approach this problem, it can leave the recording sounding cleaner.
It’s not easy to avoid microphone bleed, as it is such a common phenomenon, especially on recordings with a lot of sources. However, we hope these tips have made it easier to reduce them to manageable levels.