Why does my mic have playback?

What is Microphone Playback?

Microphone playback, also known as mic monitoring or sidetone, refers to the experience of hearing your own voice coming back through your headphones or speakers as you speak into a microphone. This audio feedback loop is caused by routing the microphone signal back to the output, creating an echo effect. The result is an echoing or screeching sound as the microphone picks up its own output and re-amplifies it continuously. If the loop gain is high enough, it can create a painful howling or squealing noise.

Microphone playback happens when your microphone audio is being fed directly into your headphones or speakers in real-time. The audio from the mic gets “played back” out of the playback device, allowing you to hear yourself. This is often done intentionally with professional audio equipment to allow performers to monitor themselves. However, sometimes it occurs unintentionally on computers when audio devices are not configured correctly.

Common Causes of Playback

There are a few common causes of microphone playback through speakers:

Having the microphone too close to the speaker can lead to feedback. The sound from the speaker goes into the mic, gets amplified, and comes back out the speaker. To prevent this, make sure to position the mic at least 2-3 feet away from any speakers.

If the speaker volume is too high, the microphone can pick up some of that audio and send it back out. Turn down the speaker volume until you no longer hear playback coming through.

Incorrect audio cable connections can create a feedback loop. Double check that cables are plugged into the proper input and output jacks. The microphone should be connected to an audio input, not an output.

How to Prevent Playback

One of the easiest ways to prevent microphone playback through headphones or speakers is to position your microphone further away from any playback devices. The physical distance reduces the chance of sound looping back into the microphone. Place your mic an arm’s length away from speakers or headphones to start with. You can also experiment with angling the mic so it doesn’t directly face speakers.

Lowering your speaker, headphone or overall system volume can also help reduce microphone playback. With a lower sound level, less audio will be picked up by the mic. Just be careful not to lower it so much you can’t hear your audio well. Reduce volume in small increments to find an optimal balance.

Using a directional microphone rather than an omnidirectional mic can focus the audio pickup in one specific direction. Pointing a directional mic away from speakers and monitors prevents it from capturing their output. Directional mics like cardioid or shotgun mics are common choices here.

Finally, use the mute function on your mic when you aren’t speaking. This prevents ambient sounds in your room from being transmitted. Enable push-to-talk or press the mute button when listening rather than talking during calls and recordings. Just don’t forget to unmute when you need to speak up!

Audio Interface Settings

The audio interface is the hardware that connects microphones, instruments, and monitors to your computer. Adjusting the settings can help prevent microphone playback and echo.

First, try lowering the main output level on your audio interface. This reduces the overall volume being sent to your speakers or headphones. Too high of a main output can bleed into the microphone and cause playback.

Next, turn down the mic monitoring level. Most audio interfaces allow you to directly monitor the microphone input. Turning this monitoring level down or off can remove microphone bleed.

Finally, enable direct monitoring if available. Direct monitoring routes the microphone input directly to your headphones, bypassing software monitoring. This can eliminate playback caused by latency or software settings.

Refer to your specific audio interface manual for steps on adjusting these settings. Getting the output, monitoring, and direct monitoring levels set correctly can go a long way in preventing microphone playback.

Source: https://www.youtube.com/watch?v=RMdnvIN2bnY&vl=en

Microphone Types

The type of microphone you use can impact how much audio playback occurs. Microphones have different polar patterns that determine their sensitivity to sounds coming from various directions. Cardioid microphones are most sensitive to audio coming from directly in front, while rejecting sounds coming from the sides or rear. This makes them good at avoiding feedback from monitor speakers or sounds bleeding over from other instruments on stage.

Lavalier or lapel microphones are omnidirectional, meaning they pick up sound equally from all directions. However, since they are positioned on the talent’s body, they mostly capture the intended voice rather than ambient sound in the room. Proper mic placement is key to preventing playback.

Room Treatment

Proper room treatment is crucial for reducing microphone playback and achieving quality recordings. The goal of acoustic treatment is to absorb or diffuse sound in order to prevent reflections that can cause playback. There are three main types of acoustic treatment to consider:

Sound absorption panels – These panels are placed strategically around the room to absorb mid and high frequency reflections. They are typically made of rigid fiberglass or mineral wool and come in various thicknesses.

Bass traps – Bass traps absorb low frequency energy and are placed in room corners where low frequencies build up. The two main types are corner bass traps and panel traps.

Acoustic foam – Budget friendly foam panels can absorb high frequency reflections. However, foam is less effective at lower frequencies compared to fiberglass or mineral wool panels.

Optimally treating a room requires a combination of absorption at early reflection points and bass trapping. Working with an acoustic specialist can help design the right acoustic treatment plan for your space and goals.

Mixer Settings

One of the most important things you can do to prevent microphone playback is adjust the settings on your audio mixer properly. Here are some key tips:

Lower the main mix level – Keeping the overall output volume of your main mix lower gives you more headroom to work with before feedback occurs. Turn it down until you stop getting feedback.

Use subgroups for monitor mixes – Route monitor mixes (like stage monitors) through subgroups instead of straight to the mains. This allows you to send a separate monitor mix without affecting the mains.

Assign mics to monitor outputs only – Any mics meant for stage performers should be assigned only to monitor outputs, not the main mix. This prevents their signal from looping back through the mains and causing feedback.

Properly setting up your mixer is crucial for taming playback. See this source for more tips on using your mixer’s EQ to eliminate feedback.

Software Solutions

There are various software settings and tools that can help reduce or eliminate microphone playback. One option is to enable an input delay or latency within your audio interface, DAW, or recording software. This introduces a slight delay to the mic signal which prevents you from hearing the direct playback. Settings like “Software Monitoring” in DAWs like Ableton Live can enable this latency.

You can also use audio plugins like gates, expanders, and de-essers to cut out the playback audio when you are not speaking into the mic. These effects will only allow the mic audio to pass through when your voice reaches a certain input level. This removes the microphone playback in between spoken parts.

Some programs like Discord have built-in visual tools like microphone clipping indicators that let you see when your mic is picking up playback audio. This can help adjust your levels and prevent overpowering playback bleed. Monitoring these visual indicators as you adjust software and hardware settings can aid the reduction process.

Headphone Monitoring

One of the most effective ways to prevent microphone playback through headphones is to use closed-back headphones. Closed-back headphones create a seal around the ear, preventing sound from leaking out into the microphone. This prevents the headphones from creating a feedback loop with the microphone.

Be sure to disable any speaker output when tracking vocals or instruments. Having speakers active while the microphone is on creates an opportunity for sound to bounce back into the mic. Monitoring your audio through closed-back headphones instead allows you to hear what you’re recording without the playback issues.

Some musicians make the mistake of wearing open-back headphones, which allow sound to freely pass in and out. The sound from open-back headphones can easily make its way into the microphone, creating self-monitoring problems. Investing in a good pair of closed-back headphones is one of the best ways to avoid playback through the mic.

Additionally, adjust headphone volume to a moderate level. Having the headphone volume too high can cause small amounts of sound leakage back into the microphone.

By using closed-back headphones and disabling speakers, singers and musicians can monitor themselves in the headphones without hearing distracting playback through the mic (https://gearspace.com/board/audio-student-engineering-production-question-zone/1172710-headphone-monitoring-what-am-i-doing-wrong.html). This creates a better tracking experience in the studio.

When to Seek Professional Help

Despite your best troubleshooting efforts, you may still experience playback issues that require professional assistance. Here are some instances when you should consider hiring an expert:

If you have gone through all the troubleshooting steps to optimize your audio interface, microphone selection, room treatment, mixer settings, and software but still can’t resolve the playback, bringing in a professional may be your next step. An experienced technician can diagnose issues in complex setups that may not be apparent to the average user.

If you rely on your audio recording and playback for mission-critical purposes, such as podcasting, video production, or music recording, then unresolved playback problems can jeopardize your work. Seeking professional help right away may save you time and frustration for important projects.

Larger, more sophisticated recording setups with multiple microphones, mixers, and other gear can have complex interoperability issues leading to playback problems. A professional can efficiently identify and address problems stemming from equipment mismatches, gain staging, and signal flow in complex rigs.