You may think that everything is perfect, but once you begin to edit the video, you will hear a hiss and realize that all your efforts have been vain.
How to remove microphone hiss? This is a very common problem and one of the main concerns for many audiophiles. We have created this article to help you get rid of unwanted hiss in your voice recorder.
What is Hiss Noise?
Hiss refers to a broadband noise covering the entire spectrum of the audible spectrum but is more intense in the higher frequencies. This would sound similar to blue noise from a technical perspective.
Hiss noise can be caused by electronic components, also known as self or inherent noise. A noise floor is the level of an electronic circuit’s inherent noise. It is expressed in decibels.
Audio circuits all produce some ambient noise. This is due to the heat energy created by moving electrons. The audio quality of the components used and the design of circuitry determines the final level of the noise floor.
The noise floor of audio gear that is more expensive has a higher average quality component and design.
Because lower-quality components can create background noise most often, it is sensible to search for the weakest link of the audio signal chain to avoid hiss. For filmmakers, the weakest link is often found in the audio input of their camera (or microphone preamp).
Use A Microphone With A Gain Boost
A signal with high gain is the best way to overcome a noisy microphone preamp. This is done to reduce gain by the camera’s preamp (i.e., leaving the volume set low), as this would add noise and microphone boost signal by another less noisy source.
There are many external microphones available for your camera today. However, most don’t offer any gain adjustment.
Azden’s SMX-30 microphones and SMX-15 microphones offer a gain control switch that allows for a 20 dB gain adjustment to the microphone signal before it goes to the camera.
These microphones are equipped with high-quality gain circuitry, which is what your camera lacks. There are two settings: a 20 dB gain increase and a nominal gain (no microphone boost). These settings apply to moderately loud or very loud sound environments.
Turn Off Auto Gain Control On Your Camera
AGC (auto gain control) is a common feature on modern video cameras, but most people don’t know about it. AGC, which is an audio compressor, regulates the volume of recorded audio. It turns up the gain when the sounds are quieter and down when they get louder.
Although this can help balance out the difference between loud and soft sounds, it has its limitations. The AGC can increase the audio volume during quiet sections of the video.
This increases the noise level, which makes it more audible. As the noise amplifies in quiet audio segments, you can often hear the result as a loud whooshing sound. This affects not only the noise inherent in low-quality preamps but also ambient noise from the environment.
If you don’t want unwanted noise, it is a good idea to turn off your camera’s AGC setting. A few models of cameras do not allow you to turn off AGC.
To find out if your camera features AGC, as well as how to turn it off, you will need to consult the manual. This feature should be considered when shopping for your next camera.
It is sad, but it is true. Even if you spend several thousand dollars on a very nice camera, most of your money goes towards making the images and videos look great. This is especially true for mirrorless cameras and DSLRs that include a microphone input jack of 3.5mm.
You’ll want to check your camera’s manual to know if your camera has AGC and how to control it and consider this feature when researching your next camera purchase.
Microphone Windshield To Block Outdoor Sounds
Foam (Windjammer) or fur (Windjammer); both products work well to block wind noises. The foam of the mic should be placed on top of the microphone’s head.
These accessories are dead cats and block wind interference, heavy breathing, and pop sounds. These windshields can block wind noise up to 12dB.
All mic windscreens will get rid of the volume of the microphone and lower the frequency levels. Windscreens achieve this feat with less background noise and audio interference. Any microphone with a windshield will produce a cleaner sound. It is worth it.
Pop Filter to Eliminate Unwanted Sound
What is a pop filter? Pop filters are useful for reducing sibilance and plosiveness from your recordings. Pop filters are not recommended for outdoor use.
They are most commonly used in the studio or home studio. It’s a filter that is placed between the mic and the speaker.
Pop filters are disc-shaped objects that can be mounted on a microphone stand. They also have a flexible boom which allows you to position it exactly where you need.
It looks like a large lollipop. The lollipop reduces or eliminates plosives so that the microphone does not pick up a lot of noise (pop noise). It also helps to block background noises.
It also helps to keep moisture away from the microphone, which is great for your equipment. Some microphones, like the SM58, include a pop filter underneath the metal casing. This helps to reduce the noises problem. Pop filters can be used to reduce sibilance noises in vocals.
Stop Listening to Background Sounds With a Microphone Shockmount
Modern microphones are sensitive and can pick up the background noise. Shock mounts can be used to protect your microphone from vibration and shocks and improve sound quality and performance.
Shock mounts will reduce microphone handling noise. Shock mounts can be used on microphone stands to reduce background noise due to vibrations and tremors caused by people walking across the floor and mic stand vibrations.
Filters For Mic Static, Hiss, Hum, And Other Sounds
Filters won’t change or add frequencies to the audio input signal. Filters emphasize signals within a certain frequency range and reject signals from other frequency bands, such as those associated with unwanted microphone sounds or background noises.
A high pass/low cut background noise filter should be applied to remove low-frequency rumbles and DC offset. If you are looking to remove the DC offset, set the frequency control at 10Hz. You can easily remove AC hum by using a harmonic notch filter at 50 Hz and 60 Hz.
These are the five main types of filters:
- A bandpass filter is used to separate signals at different frequencies or within the same frequency range from those at other frequencies.
- A filter that has the opposite function to the bandpass is called Notch or Band Reject. These filters reduce background noise by removing unwanted frequencies from signals while affecting as few other frequencies as possible.
- The Low-Pass filter allows low-frequency audio signals to be rejected and permits them to accept those below the cut-off frequency. When high-frequency are needed to be removed from a signal, low-pass filters can be used.
- High-Pass, the opposite to the low-pass filter that rejects signals below its cut-off frequency, is used. When it is necessary to reject low-frequency signals, high-pass filters can be used.
- The amplitude of an All-Pass or Phase-Shift filter type does not affect the signal’s amplitude. Its purpose is to alter the phase of the signal without affecting its magnitude.
A low cut (or high-pass) filter is the most common and can be found in any mixer. It reduces low-frequency rumbles from audio or mic signals. You can start at 20hz and increase until you reach the sweet spot. You could increase the frequency to 100 Hz for male vocals.
Female vocals can be up to 120hz. To get the best microphone noise reduction, experiment. These filters are very effective in removing static.
If background noises persist after applying the filters, you can fine-tune your signal using the equalizer.
Equalization To Remove Unwanted Audio And White Noise
What is an equalizer? The Equalizer (EQ), a hardware or software filter, adjusts certain frequencies.
What is equalization? What is equalization? It’s the optimization of frequencies of sound. The equalization process allows us to increase or decrease the volume of a selected frequency. This is useful for background noises that are generated from a microphone.
Each sound has its frequency, and some frequencies are louder than others. To equalize, these frequencies have used an equalizer. To get the best sound, we reduce dominant frequencies or increase them.
It is easy to use an equalizer, especially if you have its analyzer. You can see which frequencies are affecting your performance and adjust accordingly.
If you’re dealing with an audio recording, and for example, if the recording of your voice contains white noise (hiss), and your analyzer shows that the dominant frequency is 7khz, then select that frequency and reduce it using your equalizer. It should be possible to fix white microphone noise instantly.
If you prefer live performance and don’t have a digital mix, you can rely on your ears. Each tone has its frequency. A microphone placed incorrectly on a stage can cause feedback issues.
You may also experience certain sounds that are more noticeable because of background noise and acoustic echo cancellation. However, you can use equalize as an alternative to try and eliminate this problem.
You can cancel an echo with some equalization skills. You can practice identifying the frequency that is missing or accentuated.
How to cancel unwanted sounds with a noise gate
A noise gate is used to reduce background noise and unwanted noises. It allows audio signals to pass only when they are above a threshold.
It is used when the sound audio signal is higher than the noise level. 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.
It will not affect the sound source. It can be adjusted to reduce background noise and static audio picked up by your microphone, whether at the stage or in the home studio.
You can try switching to another power socket if you still experience mains hum causing audio interference.
Software and hardware that are used to create noise gates usually have 5 parameters:
- The threshold is the threshold at which the gate will open to allow sound through.
- The ratio refers to the balance between the original and gated sounds.
- Attack determines the time it takes to make the gate open from closed to open.
- After the threshold signal has been reached, hold allows the gate to remain open.
- The release setting controls the time it takes for the gate from closed to open fully. The noises sound is cut off quickly by a fast release. A slower release acts as a fade-in.
Software for Noise Reduction and Audio Recording
If there is no other solution, you will need to use noise reduction software. This can cause audio data loss. Sometimes it’s better to leave noise in your recording than to delete a large portion of your audio material.
Software that removes background noise from audio signals is called Audio Noise Suppression Software. Any noise suppression process aims to isolate noise from a signal.
There are many noise-canceling software plug-ins available which all noise reduction plug-ins work on the same principle. Get noise print, and – apply. Only additional parameter settings make the difference. For sound restoration, some companies offer full-featured DAWs (digital audio workstations).
The well-known Izotope has the latest rx7 audio editing software for post-production that offers incredible possibilities to achieve a professional sound. Editing software is worth every penny. De Noise and De Click, De Crackle, De Hum, De -Plosive, De Ess, De Reverb, De Rustle, De Wind, Dialogue Isolate. Voice DeNoise. Voice DeNoise. Mouth DeClick. EQ Match plug-ins.
It’s fantastic stuff. Adobe (Audition CC), Acon Digital (7Acoustica 7, Restoration Suite), Audacity, Waves Antares (SoundSoap), Zynaptiq (8-series), Sound Forge, and Cedar Studio are other companies that are well-known for their audio restoration software.
It is easy to guess which one is the most loved by audio hobbyists.
Audacity, a free audio editor software that includes a Noise Reduction tool plug-in, is available for Windows 10, Windows 7, Apple Mac OS, and Linux.
Although it doesn’t have as many advanced options as rx7, this noise suppression software can still do the job if your goal is to record your performance and remove any background noise from your recordings.
It is straightforward to use Audacity for noise removal. First, open the plug-in and select the area of your audio recording that only contains the room tone or noise. Next, click get noise profile.
After selecting the audio, you wish to remove background noise, click on ok. You can adjust other parameters to get a better sound. If you need to cancel out echo, it is possible.
This can be done with a USB audio interface, a PC soundcard, or any other source such as a portable recorder, mixing console, or video camera.
You should ensure that your audio drivers are current if you record from a computer. An out-of-date driver could cause clicks, crackles, and other noises. You should also ensure that your OS is up-to-date if you use Windows 10.
Adaptive Noise Reduction Technology and Cancellation Technology
The noise cancellation method uses an audio input signal that contains no noise. The adaptive filter then reduces the movement from the primary input. This Noise Reduction effects reduce background noise such as fans, air conditioners, and background conversations.
Nearly all advanced Noise Reduction software includes an adaptive noise cancellation feature that noise suppression is helpful for real-time (or live) noise removal.
Every audio recording has some ambient noise. These unwanted sounds need to be reduced as much as possible to produce the best audio recordings. Ambient noise reduction used to be a costly and challenging process.
Thanks to the new high-speed computers with microphone noise-canceling software and quality sound cards, audio noise removal has become effortless.
You can also use a real-time noise cancellation microphone. As technology advances, ambient noise cancellation filters get better.
These tips will ensure that background noise is not present in your studio recordings or live performances. You can reduce background noise in your output signal by using microphone noise reduction software. That’s all there is to it.
In addition to choosing for yourself a quality microphone, capable of capturing good sound, applying the tips we have listed above is also a good method to reduce unwanted voices of the mic.
If you have any better options, leave them in the comments below. Hooke Audio will upgrade and finish the article when possible.