How To Remove Microphone Hiss
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Unwanted background noise is one of the main challenges of recording with a microphone, and there are actually quite a few types of noises you might encounter while recording. Luckily, there are many different ways we can cancel these unwanted sounds out, especially if they’re coming from a physical source.
However, when listening back to your audio, you might encounter hissing sounds in your recording which might sound different from your typical ambient noise. While this could also be coming from an outside source, it may also have to do with technical issues and the way your camera, dynamic mic, or condenser mic are set up.
Here are possible reasons for the unwanted noise you’re hearing and precautions you can take to get rid of that pesky hissing noise in your recordings to get great sounding audio every time.
Why is My Microphone Hissing?
Electrical Sources
Electrical sources will be the most common noise sources within your home or recording space, and can easily be the cause of that hissing noise. The reason you probably don’t notice these sounds in the first place is that you’re so used to hearing them faintly in the background, such as your air conditioner or light bulbs. With a sensitive microphone like a condenser mic, these moderately loud and soft sounds can easily be picked up and affect your recording quite a lot.
Turn off your AC while you record and get rid of fluorescent light bulbs and Christmas lights, as these emit a buzzing sound that can easily be picked up by condenser microphones especially. Opt instead for LED light bulbs which don’t emit any hissing sound.
Outside Sources
While electrical noise is coming from within your recording space, outside sources are ambient noise that you can’t control outside of your recording environment.
Loud sound environments such as busy roads can be difficult to avoid especially if you’re recording within a city, but you can still take precautions to avoid these sounds from being picked up by your dynamic mic. Record away from windows and doors and stay within soundproofed spaces that are smaller and more secluded.
Closets and bedrooms, for example, are the most ideal spots for recording podcasts with a condenser microphone, and recording closer to your mic will drastically improve the speech-to-noise ratio and overall audio quality.
Equipment Sources
While controlling physical noises within and outside your recording space will help greatly, you will also have to take into consideration your actual microphone and recording equipment.
Electronic devices naturally emit sound, and this noise that audio circuits generate is called inherent noise, self-noise, or noise floor. Hiss sounds are a broadband noise similar to blue noise that spans the entire audible spectrum but with more intensity in the high frequencies and comes from this very reason. The level of a hissing sound can depend on the equipment’s noise floor and quality.
It’s also worth checking whether the XLR cable used in your recording is set up properly, as faulty cables could also create background noise.
How to Remove Microphone Hiss
Use a Microphone With a Gain Boost
The best way to combat a noisy microphone preamp is to feed it a signal with a lot of gain.
Turn off your automatic camera auto gain control or audio compressor which can cause hissing noises in quiet audio segments, and instead opt for higher quality, external microphones with gain adjustment for more effective noise removal and control.
Opt for dynamic microphones on the market that have a gain control switch that allows you to add clean gain to the microphone signal before it is sent to the camera for more effective noise reduction.
Know Your Mic Type
Knowing what kind of XLR mic you’re connecting to your camera is crucial when you want to avoid or remove background noise. Knowing the difference between condenser mics and dynamic mics and what type of environments they’re best suited for is the first step in ensuring you get the best sound quality from your type of recording.
Knowing your XLR microphone and its recording signal, whether you have to bring up the gain level on your camera’s preamp or audio interface, or even whether it requires phantom power or not will also factor into whether you will hear hiss in your mic or not.
Invest in Quality Equipment That Can Reduce Unwanted Noise
The best way to get rid of that hissing noise and reduce background noise, in general, is to prevent it from happening from the start. A cheap camera purchase will inevitably lead to noisier components that will be heard in your recording and will be harder, and sometimes more expensive, to cancel out.
Because lower quality components are the most common cause of background noise, the most sensible move is to find the weakest link in the audio signal chain to avoid hiss. Oftentimes, this is the camera’s audio input or preamp.
Investing in equipment that’s built to block out unwanted sound is your best bet for getting consistent quality sound. Look for a quality microphone with high-quality gain circuitry that you can use separately from your camera’s audio interface.
Additionally, using a noise gate during your recording sessions can greatly reduce background noise and unwanted noises. It allows audio signals to pass only when they are above a threshold. The noise gate can reduce the static noise from the amplifier, and the hum from the power supply system and cable provided it is appropriately set without affecting the sound source.
Use Noise Reduction Software to Keep Background Noise at Bay
If you’ve already surpassed the recording stage and need to remove background noise from your already recorded audio, using noise reduction audio software on your digital audio workstations is a final option that can be very effective.
Final Note
No matter what equipment you’re using, whether it’s dynamic mics or condenser mics, background noises are an inevitable hassle anyone will experience, and an even bigger problem is not knowing their source.
Hissing sounds are one of the most common sounds to hear in your audio recording, and while it can come from physical sources around you, this sound can also be caused by electronic components within your own equipment.
Being able to get rid of these noises before you record audio is the best solution, but we’re glad there are also post-recording options that allow us to avoid recording all over again. Make recording audio and effective noise reduction so much easier by following these tips and tricks and give yourself great recording quality whenever you turn on your mic.
