How to Fix IPTV Audio and Video Sync Problems

Few things are more distracting than voices that do not match lips. Once you notice it, you cannot stop noticing it. Audio and video sync problems — sometimes called lip-sync issues — can come from the stream, the player, the TV or the audio equipment between them.

This guide helps you identify where the delay is being added, then fix it at the right point.

First, work out which way it is wrong

• Audio early: you hear a word or sound before you see it.
• Audio late: you see a mouth move or a ball being kicked before you hear it.

Audio late is far more common, because TVs, soundbars and wireless audio all add processing time.

Step 1: Narrow down the cause

Run these quick checks in order:

1. Change channel. If only one channel is out of sync, the stream is the likely cause.
2. Play the same channel on another device. If it is in sync there, the issue is your original device or audio setup.
3. Switch to the TV’s own speakers. If sync becomes correct, your soundbar, receiver or headphones are adding the delay.
4. Restart the channel. Sync that drifts gradually during a programme often resets when the stream restarts.

Result	Most likely cause
One channel only, on all devices	The stream itself
All channels, one device only	Player or device settings
Fine on TV speakers, wrong on soundbar	Soundbar, receiver or HDMI ARC delay
Wrong only with Bluetooth	Bluetooth latency
Starts fine, drifts over time	Player buffering or a player bug
Wrong after skipping in a film	Player — restart playback

Cause 1: Soundbars, receivers and HDMI ARC/eARC

When audio travels from the TV to a soundbar or AV receiver, especially over HDMI ARC or eARC, each device processes the sound. If they do not account for each other’s delays, audio ends up late.

Fixes:

• Use the TV’s audio delay setting. Common names include Digital Output Audio Delay on Samsung TVs and AV Sync Adjustment on LG TVs. Other brands have similar options in their sound settings.
• Use the soundbar’s or receiver’s sync setting, often called AV sync, lip sync or audio delay.
• Turn on automatic lip-sync on the TV and audio device if available, which lets them communicate delays over HDMI.
• Connect the streaming device to the receiver, and the receiver to the TV, if your equipment supports 4K passthrough. This can keep audio and video on the same path.
• Update firmware on the TV and soundbar.

Cause 2: Audio passthrough and surround formats

With passthrough enabled, the player sends formats such as Dolby Digital directly to your audio equipment. Decoding these can add delay on some setups, and a few combinations produce drifting sync.

Fixes:

• Toggle passthrough in the player’s audio settings and compare.
• Try the device’s audio output format settings — for example, switching between automatic, stereo and surround output.

Our player settings guide explains passthrough in more detail.

Cause 3: Bluetooth headphones and speakers

Bluetooth always adds some delay. Whether you notice it depends on the codec, the headphones and whether the device compensates.

Fixes:

• Check your streaming device or TV for a Bluetooth audio delay or audio sync adjustment.
• Use headphones or speakers that support a low-latency Bluetooth codec your device also supports.
• For regular TV viewing, wired headphones or a TV headphone system designed for low latency avoid the problem.

Cause 4: The player

Players manage audio and video timing themselves. A player bug, an interrupted stream or skipping around in on-demand content can knock them out of step.

Fixes:

• Restart the channel or title.
• Use the player’s audio delay option, if available, to shift audio earlier or later in small steps. General media players such as VLC offer audio track synchronisation settings.
• Update the player, or test with a different reputable player.
• Clear the player cache and restart the device.

Cause 5: Frame rate and video processing

Heavy video processing on the TV — motion smoothing, noise reduction and some “enhanced” picture modes — delays the picture. The TV should delay audio to match, but it does not always manage perfectly.

Fixes:

• Reduce motion smoothing and other heavy processing, especially for films. Our TV picture settings guide explains what each setting does.
• Turn on match frame rate on your streaming device so the TV does less conversion.

Cause 6: The stream itself

Occasionally, audio and video are already out of step in the stream you receive. This usually affects one channel consistently, on every device.

Fixes:

• Try an alternative version of the channel if your list includes one.
• Report the channel, the time and whether audio is early or late to your provider.

Adjusting sync by hand: a simple method

If you need to set a manual delay:

1. Find a scene with a clear, close-up speaker or a sharp sound.
2. Change the delay in small steps — many settings move in increments of tens of milliseconds.
3. Stop when lips and voices match; if you overshoot, step back.
4. Check on two or three channels, because the right value should work across them if the delay comes from your equipment.

Set the delay where the problem is: on the TV or audio equipment if every source is affected, or in the player if only IPTV is affected.

Prevention tips

• Keep the TV, soundbar, streaming device and player updated.
• Avoid chaining several audio devices unless you need to.
• Use automatic lip-sync features where your equipment supports them.
• Restart long-running streams occasionally, especially if sync drifts.

The takeaway

Audio sync problems come from wherever delay is added: the stream, the player, the TV’s picture processing or the audio equipment. Test with TV speakers and another device to find the source, then fix it at that point — using the TV or soundbar delay for your whole setup, or the player’s delay when only IPTV is affected. If one channel is out of sync everywhere, report it. For other playback problems, our IPTV troubleshooting checklist is the place to start.