How to Sync Radio Commentary with TV Broadcast (October 2026)

You sync radio commentary to television by measuring the real offset between the two feeds and then adding that many seconds of delay to the commentary, because the radio is normally running ahead of the TV picture rather than behind it. Most setups need somewhere between one and eight seconds, though a badly buffered stream can be a full minute or more out.

It takes about ten minutes to set up once, then thirty seconds per event afterwards if you write the number down. You need the TV feed, the radio feed, something that can delay audio (an app, a computer, or a small hardware box), and a way to hear both at the same time.

This matters most when you would rather follow your local or specialist announcers than the national TV commentary, when you are watching a match broadcast on a delay in another time zone, or when you are mixing a station commentary with a televised picture for a stream. Whatever your reason, the method is the same each time, and it takes one careful measurement rather than a night of guessing.

Table of Contents

• What You Need
• Step-by-Step: How to Sync Radio Commentary with TV Broadcast
  • Check Both Audio Sources and Formats
  • Measure the TV Broadcast Delay
  • Add or Remove Audio Delay
  • How to Sync Radio Commentary with the TV Broadcast
  • Monitor and Test the Final Playback
  • Use the Same Delay Setting Every Time
• Common Mistakes
  • Fixing Timing, Audio, and Connection Problems
  • Tips for a Stable Radio-to-TV Setup
• Frequently Asked Questions
  • Can I sync radio commentary to a live TV channel?
  • Why does radio commentary sound early or late when streamed with TV?
  • How much delay is normal between television video and streamed commentary?
  • What software can add delay to a radio audio feed?
  • Should I delay the video or the radio commentary instead?
  • How do I keep audio synchronized when the internet connection changes?
• Conclusion

What You Need

Five things, and four of them you almost certainly already have.

• The TV source. A set-top box, a free-to-air tuner, a connected TV app, or a capture card feeding a computer. Note whether it is satellite, cable, terrestrial or internet-streamed, because that decides how much delay you will be chasing.
• The radio commentary source. The station’s app, its web player, an M3U playlist, or a tuner. Internet streams are the common case and they almost always start faster than a broadcast TV chain.
• A delay tool. A radio app with a delay slider, an audio editor or DAW on a computer, or a hardware delay processor. Phone apps are the quickest; a computer is the most flexible; a box is the most reliable once set.
• Monitoring. Headphones on the programme mix, or a speaker and a camera feed you can see at the same time. Judging sync by ear alone is where most people go wrong.
• A note. Somewhere to write the number. Once you know the offset for a pairing, you rarely need to measure it again.

Here is how the practical options compare.

• DVR or pause button on the TV. No extra gear, takes seconds, works only when the television side is the one running behind. You cannot use it when the radio is ahead.
• Radio app with a delay slider. Usually the fastest genuine fix on a phone or tablet. One app in the App Store listing I looked at holds up to 300 seconds of delay, imports M3U and TXT playlists, and handles MP3, M3U8 and AAC streams. Check it keeps playing when you switch to your TV app.
• Computer audio software. Free editors and DAWs have a delay effect built in, and routing lets you send the commentary out through your speakers or headphones. Unlimited range, but you need the stream on the computer.
• Hardware delay processor. A small box that takes line or USB in and out with a numeric delay display. Rock solid once dialled in, and listeners regularly complain they cannot source one easily, so only buy it if you are doing this weekly.
• Built-in broadcaster sync. Some station apps now ship their own slider. Nine Radio’s Audio Sync feature, for instance, offers in-stadium, free-to-air and streaming presets so you pick a delay instead of measuring one. Worth checking before you buy anything, because a station that already builds in the sync saves you the whole exercise.

For UK listeners, the pairings you are most likely to be correcting look like these.

• BBC Radio 5 Live or a local BBC radio station against Sky Sports, BT Sport or TNT Sports on satellite. The satellite side carries the most processing, so the radio arrives first and you are chasing a few seconds. A Digital Spy thread put BBC Radio football commentary against Sky TV at roughly five seconds of drift.
• An internet radio stream against free-to-air terrestrial TV. Both sides are lean, so the offset is often under a second and easier to hold.
• Any stream against a streaming TV app on the same television. The picture is usually a few hundred milliseconds behind, and both feeds rebuffer independently.

Matchups against streaming platforms can be much worse. A thread on the Android subreddit described a streamed game feed running around half a minute behind, where the practical answer was to pause the television until it caught up. If your offset is that large, rule a simple delay slider out before you start.

The same method works outside sport too. Election night, festival coverage and breaking news all have the identical problem: commentary from one source describing pictures from another. Nothing about the procedure changes when the content does.

Step-by-Step: How to Sync Radio Commentary with TV Broadcast

Work through these six steps in order. The measuring step is the one that matters, and it takes longer than most people expect.

Check Both Audio Sources and Formats

Play the TV and play the radio at the same time before you touch any settings. If one of them is muted, buffering or running in the background, any number you set will be wrong.

Listen for about a minute and decide which side is late. If the commentator describes a shot before you see it, the radio is ahead and the delay belongs on the radio. If you see the shot and hear it a beat later, the TV is behind and you can try the DVR pause instead.

Note the stream format too. MP3, M3U8 and AAC streams behave differently from a broadcast feed, and an app that only accepts a direct MP3 playlist URL will not help if your station hands you an M3U8 manifest.

Measure the TV Broadcast Delay

You need one clean visual moment that both feeds share. A kick-off, a goal, a scoring shot, a penalty countdown, a start of play at a corner, a lap flag, a home run into a busy crowd. Silence is not good enough; you want something with a hard visual edge and a spoken reaction attached to it.

Wait for the next unmistakable one, then note the time. If the whistle goes at 19 minutes and 12 seconds of your stopwatch and the word “goal” finishes at 19 minutes and 17 seconds, you have five seconds of offset. A Digital Spy thread about BBC Radio football commentary against Sky TV put the drift at roughly five seconds, which is a useful first guess for a UK satellite pairing.

Do it twice before you commit. If you get 5.0 and then 5.4, the number is about five seconds and a bit of drift, not a clean figure.

Here is a fuller worked example. Start your stopwatch the instant the whistle blows and stop it on the last syllable of the commentator’s first word after it. Say the whistle reads 20:00 and “goal” lands at 20:06, so you need six seconds. If the next hard cue measures seven, you are drifting and five to six is your real figure. When two measurements disagree, take the lower number and keep a small margin, because a correction of one side of the offset is far easier to fix live than one that pushes the commentary late.

Speaking of the penalty countdown: fans syncing a local radio call to a national broadcast often simply wait for the referee to start it and start the stopwatch there. It is a spoken marker attached to an obvious visual action, which makes it a better cue than anything on the scoreboard.

Do not use the scoreboard clock alone. Graphics lag the action and will send you chasing a number that is not the real offset.

Add or Remove Audio Delay

In a phone or tablet app, find the delay or sync control, set it to the measured figure, and confirm playback begins from silence or a low source so the delay actually applies to the start of the stream.

On a computer, route the radio stream into an audio editor or DAW, add a delay effect on that track, and set the delay time in seconds. Free editors and DAWs all ship one. If your effect caps at a couple of seconds, chain a second instance in series, which is the same trick a long-running Mac guide used with two-second delay units to get past eight seconds.

If you are doing it in a live playout chain rather than an editor, the delay goes on the commentary bus before the mix rather than on the recorder, so the fix is part of the output instead of baked into a file.

Adjust in single seconds first, then half seconds. Fine steps matter more than a large delay ceiling, because the offset changes during the event.

How to Sync Radio Commentary with the TV Broadcast

With delay set, find the next hard cue again and check it. The spoken word should land on the frame, not before it and not after it.

If commentary still arrives early, add delay. If it now arrives late, take delay off. Most people get the direction wrong the first time because the radio being early is genuinely confusing when the rest of your setup assumes the television is the reference.

Check a second and third cue after that, spread a few minutes apart. One match means nothing if you tuned it to a single goal.

Test on the device you will actually watch on. A phone held next to a laptop screen is a different setup from a delay applied on the computer and played out through the television, and the second one adds its own few hundred milliseconds.

Monitor and Test the Final Playback

Watch the programme output, not the source. Whatever the audience hears is the only mix that matters, and it is often not the mix you tuned against.

Check for the three things that ruin a synced mix: drift over time, echo or comb filtering from two audio paths running together, and clipping where a boosted commentary bus hits a hot level. Run the test at the volume you will actually use, since some broadcast paths only behave at level.

On a livestream, watch the platform’s own preview rather than the encoder’s local view. Streaming platforms add their own buffer and occasionally their own lip-sync correction, and a stream can look fine locally and arrive late.

If your stream is wireless, expect trouble. Chromecast, AirPlay and Fire TV devices re-buffer on their own schedule and have been a recurring source of “it was in sync and then wasn’t” complaints. Wired beats wireless here every time.

Use the Same Delay Setting Every Time

Write the number down with the pairing next to it: station, channel, roughly when you measured it, and the delay in seconds. That turns a ten-minute task into a thirty-second one next week.

Label the app preset or the saved project after that pairing rather than after a single station, since the offset belongs to the combination, not the station.

Re-measure whenever the broadcast path changes. A different channel, a different provider, a new streaming encoder, a switched internet connection, a firmware update on the box, or a different TV set all move the offset.

Keep the note current rather than trusting it forever. Drift is the normal state, not an error.

Drift is worth separating from a wrong number. During a broadcast, ad breaks, replays, stoppages and referee decisions hit the television feed very differently from the radio, so an offset that measured five seconds at kick-off can be eight by half-time and back again after a break. That is a re-tune, not a failure: wait for the next clear cue, adjust by the amount it has moved, and write the new figure down for next time.

If you are capturing the synced result for later, delay the recording bus rather than the file after the fact. Fixing it in post means re-measuring every time, and you will have forgotten what the offset was.

Common Mistakes

Fixing Timing, Audio, and Connection Problems

These are the errors that come up over and over on the forums, with the correction that actually settles each one.

• Correcting in the wrong direction. If commentary arrives before the picture, add delay to it. Adding more delay to the commentary when it was already late makes it worse and usually gets abandoned at that point.
• Judging by ear alone. Human timing accuracy is poor, especially at low volume or in a noisy room. Watch the cue and use a stopwatch, or slow the replay down and check it.
• Delaying the wrong feed. Two delay devices on two feeds splits the error instead of fixing it. Pick one, usually the radio, and leave the TV alone.
• Treating buffering as misalignment. A stream that stutters is buffering, not mis-sync. Fix the buffer first, then measure, or your number is noise.
• Applying delay to the record instead of the output. A file with delay baked in sounds right in isolation and wrong on air. Delay the bus that feeds your monitors and your stream.
• Monitoring with speakers in the wrong place. If the commentary comes from a phone on the table and the television from across the room, the room adds its own timing impression. Get the two as close together as the setup allows.
• Confusing this with lip sync on the television. If the TV’s own dialogue is out of step with the TV’s own mouth movements, that is a television or soundbar setting problem and no amount of radio delay will touch it.

One more worth naming: syncing against a feed with a huge offset. When the gap runs to tens of seconds, a delay slider alone will not get you there, and the choice comes down to a large-ceiling app or a hardware box.

Tips for a Stable Radio-to-TV Setup

• Go wired wherever you can. Wi-Fi on both the stream and the television is the most common cause of a setup that was in sync at kick-off and drifted by half-time.
• Watch the actual programme output, not a source window or a return feed.
• Transcode once. Every extra conversion adds buffering and makes the offset move.
• Leave a small margin rather than nailing the number exactly. Two seconds of headroom on the correct side is easier to live with than a perfect setting that slips.
• Test on every destination device you use, including the one you will stream from.
• Keep a one-tap reset to zero delay between events so you never carry last week’s number into tonight.
• Check the app keeps playing when you switch to the television app or lock the screen. Several radio apps pause or get suspended when they lose foreground focus, which looks like sync drift but is not.

Frequently Asked Questions

Conclusion

Start by measuring, not by adjusting. Pick one unmistakable moment, time it on both feeds, and write the number down with the station and channel beside it.

Then set that many seconds of delay on the radio commentary, check two more cues five minutes apart, and listen to the real programme output rather than the source. When it drifts later, nudge the delay and check again.

Ten minutes of measuring saves you guessing for the whole season, and 2026‘s broadcast paths will not stay as consistent as you would like.