Cleanfeed Knowledgebase

Eliminating echo

Hearing echo in your Cleanfeed session? Echo, or feedback, can be one of the more difficult problems to diagnose, and can ruin your recording. Here are some common causes of these problems, and how to handle them.

The sound of an echo comes when sound is being reflected back. That familiar ‘echo’ sound is the original sound, with the reflected one over the top. The reflected sound is slighty delayed, which is what makes such an odd sound.

In nature, for example a cave, the echo happens from hard, flat surfaces such as the walls, causing sound to bounce back and forth. Usually this echo is unpleasant, but not overwhelming; only a small fraction of the sound gets reflected. In software and hardware, it happens when we accidentally send audio back to the place where it originates from. Often this is quite a lot (or all) of the sound, and this is the cause of the disruptive echo that you might be experiencing.

In the very worst case, if both parties accidentally send audio back then we can get an echo that increases in volume, and maybe even a squeal sound (the kind that the movies use to show us somebody has a microphone). This is proper feedback and can be quite nasty — meaning we have two separate problems to fix, one at each side.

Let’s go through a checklist of the causes of echo and feedback, starting with the most likely ones first.

When someone complains of an echo, most likely the problem isn’t them — it’s the other person.

Being in the same room

It may sound obvious, but this is one of the first ones to check. Of all our requests for technical support, this comes up a suprising amount.

One of the first tests we have seen people do with Cleanfeed is to open two machines together; eg. your desktop, and laptop, and start streaming audio between them.

Unfortunately this will immediately result in an echo. When you speak, you’re picked up by two separate microphones. Digital machines take slightly different amounts of time to process the audio, sending it via your WiFi or Internet.

You’ll get the same effect if you make eg. a mobile or cellphone call between two people in the same room — try it! The echo that sounds like you coming from two places is just that; it’s actually you being picked up from two places!

Make sure you and your remote guest are actually in different rooms and can’t hear each other through being nearby.

If you actually do need to use Cleanfeed with two microphones in the same room, check out our guide.

Apple Earbuds

Let’s eliminate another common cause of echo that happens far more often than it should.

We introduced above that echo comes from reflected sound; whether from natural sources, or technical ones. And the most common technical source of this is the mainstream Apple Earbuds. Certain versions of these quite literally take the audio being sent to the headphones, and send it back through the microphone. If you had to build an echo machine this would be it. The culprit seems to be the ones with the 4 pole jack plug.

So, don’t expect usable results from these. They might be good for phonecalls, but not for your studio.

If you’re interested, this is the cause of poor audio in other apps (eg. Skype) too, where the software is working hard to cover up the echo sound. You might not hear it as an echo, but it means conversation becomes more difficult and people have to take turns to speak. Using a different device will help with these applications, too.

Mono, stereo and 4-pole mini jack plugs
Mini jack plugs have different contacts, and not all are compatible

Sometimes you have no option when you find your guest only has Apple Earbuds, and you’ll want to give them a slap on the wrist but make the best compromise. Look below for our tips on "Enabling Cleanfeed’s echo cancellation".

Someone has no headphones

Right, now we’ve eliminated a couple of silly causes, it’s on to real causes of echo.

Ever seen inside a radio studio? You’ll see almost everyone wearing headphones. Anytime they are interacting with audio from elsewhere the headphones are crucial; like a telephone caller, remote guest, or music.

The same applies to your Cleanfeed session. The guest has no headphones and just speakers? You’ll be hearing yourself from your own mouth, but you’re also hearing the sound of your guest’s speakers. And the sound of your guest’s speakers is... another you, delayed.

Switch the role of the host and the guest and the same applies. Or in a session with three or more people, just one person can be providing an echo, ruining the experience for everyone else.

For good results, everyone should be wearing headphones. And that means actually wearing them; headphones around a person’s neck are usually right next to the microphone!

Illustrating loop-back audio in a session
If you’re wondering who’s reflecting audio, try looking for it. Ask everyone else to stay silent and try speaking. If you see someone else’s audio meter moving when yours does, they’re the source of your echo.

Sometimes you have no option and a guest doesn’t have headphones. You’ll have to compromise, and see the section below which tells you how to use Cleanfeed’s echo cancellation.

Headphones too loud

Following closely behind no headphones is headphones too loud. If someone has their headphones really loud, the effect is the same as a pair of small speakers close to the microphone.

There are a number of reasons to turn your headphones down; not just echo. Consider the health implications and potential for hearing damage, too.

It could also be that the headphones are particularly susceptible to sending sound to those around them as much as the person wearing them. Cheap in-ear headphones can be the worst; you might have sat next to someone on a train or bus using these. They aren’t great for interviews or recording.

If you’re buying new headphones specifically for interviews or podcasting, consider a pair of closed-back headphones that are comfortable and fit over your ears. A long time industry favourite is the Beyerdynamic DT770.

Mixing desk set up incorrectly

You might have someone connected to your Cleanfeed session who’s using a mixing desk — sometimes known as a mixing board or broadcast console. You might need to remind them that they should be sending back a ‘mix-minus’.

Checking or testing for a mix-minus is easy. Ask the person with the mixing desk to stay silent, and let you speak. When you speak, do you see their meter in the main Cleanfeed studio screen move as well as your own? If their meter moves when you speak, the mix-minus is not set up correctly.

Cleanfeed has built-in recording and level controls, which eliminate the need for most mixer hardware. If you’re only using one microphone, consider whether you need a mixing desk at all.

Capturing the ‘desktop’ audio

This one is especially likely on Windows 10, which seems to make it particularly common or easy to do, and could be happening at the source of the echo.

Windows sound settings, displaying the stereo mix
          device
Stereo Mix on Windows 10 can be a source of echo when using a microphone

Other platforms may have similar settings; they could be labelled as Capture the desktop audio or something similar. It could depend on the manufacturer of your audio interface.

To fix, select the Gear icon in Cleanfeed next to the person who’s at the source of the echo. This will display their settings. There's a menu for the capture device; it probably displays Use browser setting. Instead, select the name of your microphone or audio device directly.

Dropdown menu to select another input device
Avoid problems with Windows default audio device by selecting the microphone or audio interface directly.

Enabling Cleanfeed’s echo cancellation

It’s time for our last resort. Sometimes a guest joins without ‘studio quality’ equipment. They don’t have headphones, and maybe they are using the microphone that’s built in to their laptop. We’d like to interview them and we’re willing to compromise on audio quality; after all, that’s better than no interview at all.

Select the gear icon next to the participant’s name. We’re going to adjust the audio settings of the person causing the echo — the person with the setup that is lacking.

From the settings, select Echo cancel from the menu, to eliminate the echo at the expense of overall sound quality.

Audio settings menu with Echo cancel
            highlighted
Enable echo cancellation on a microphone

If you temporarily enable Echo cancel on your own microphone, for testing, remember that it does impact audio quality. So you’ll want to switch it off later!

This is a summary of the common causes of overwhelming echo in a session or recording. If you’re still experiencing echo, it might be different, but closely related to the ones above.