DisplayHUB streams your video over the local network, which adds a small, consistent delay between your source and what appears on the TVs. For DJs and karaoke hosts, this means your live PA audio can feel out of sync with the video your guests are watching. Here’s why it happens and the two easy ways to fix it.
When DisplayHUB encodes and streams your video, it introduces a small but consistent delay — typically around half a second (500ms) on most systems. Your PA system plays your audio live with no delay, but the video on the TVs lags behind by that same amount. Guests watching the screens hear music or voices that feel just slightly ahead of what they see.
Note for Roku users: Roku devices buffer significantly more than other decoders and can add approximately 6 seconds of delay on top of DisplayHUB’s own latency. If your venue uses Rokus, the gap between live audio and on-screen video will be much more noticeable.
The fix is to make your PA audio go through the same delay the video does — so both arrive at your guests’ eyes and ears at exactly the same time.
This is the cleanest fix and requires no software changes. Your DJ or karaoke computer sends its output through HDMI into the DisplayHUB encoder. That signal travels through the network and comes out the other end at a DisplayHUB decoder. By “decoder,” we mean using the audio out of a TV or attaching an HDMI audio extractor to a stick/dongle. The HDMI output of that decoder is already delayed to match the video exactly.
Place an HDMI audio extractor on the decoder’s HDMI output before it reaches the TV. The audio it pulls off is perfectly in sync with the picture – feed that into your PA or mixer and you’re done. This works especially well for Roku setups where the delay is large and hard to match manually.
If running a cable from the decoder isn’t practical, you can delay your audio output to match DisplayHUB’s latency. Most DJ and karaoke software supports an audio output delay or sync offset setting.
To measure DisplayHUB’s latency: clap in front of the camera and count the gap between the clap and the flash on the nearest TV. For most systems this will be around 500ms. Dial in that same delay in your software and both will arrive in sync.
See below for where to find this setting in common software.
For Option 2, here’s where to find the audio delay or sync offset in common DJ and karaoke programs. Start with around 500ms and adjust by ear.
Go to Settings → Audio. Look for the Latency or Audio Sync slider. Virtual DJ also has a per-deck video sync offset if you’re using its video output features.
Serato doesn’t have a direct audio output delay slider. Your best option here is Option 1 — extract audio from the decoder side — or use a digital mixer that supports a configurable delay on the main output channel.
Go to Preferences → Audio. Look for Audio Output Latency compensation. If you’re using rekordbox in Performance mode with a DVS interface, you can also adjust the buffer size to fine-tune timing.
Go to Settings → Audio and look for the Audio Latency or output buffer setting. Increase the value to add delay to the audio output to match your DisplayHUB latency.
Go to Settings → Audio and look for the Audio synchronization offset slider. Enter a positive value (in milliseconds) to delay the audio relative to the video signal.
Go to Settings → Audio/Video and look for the Audio/Video offset setting. A positive value delays the audio, which is what you need to match DisplayHUB’s video latency.
This is the most common complaint. The video is delayed but the PA audio is live. The simplest fix is Option 1 — pull your audio off the decoder HDMI output, where it’s already in sync with the video on screen.
DisplayHUB’s latency is consistent once streaming is stable. If the delay feels like it drifts, check your network for congestion — other devices streaming or large downloads can affect timing. Connecting the encoder via Ethernet instead of Wi-Fi almost always solves this.
TVs add their own processing delay on top of DisplayHUB’s. Enable Game Mode on your TVs to minimize this — it disables internal post-processing that can add lag. For Option 1, use the decoder connected to the TV closest to the DJ booth as your audio reference point.
On most systems DisplayHUB adds around 500ms (half a second) of latency — enough that live PA audio will feel slightly ahead of the video. Roku devices are the exception: they add approximately 6 seconds of additional buffering on their end, which makes the sync issue much more obvious. To measure your specific setup, clap in front of the camera and watch the nearest TV — count the gap between the clap and the visual.
Yes. Run your karaoke software output through HDMI into a DisplayHUB encoder. On any decoder in the venue, extract the HDMI audio and feed it to your PA — lyrics and music are already perfectly in sync with what’s on screen. Alternatively, use the audio offset setting in your karaoke software (see the section above).
Any passive HDMI 2.0 audio extractor works. Look for one that outputs a 3.5mm stereo or RCA analog signal — or TOSLINK digital if your mixer has that input. They’re widely available for $15–$25. No drivers, no setup: plug it between the decoder and the TV, and the audio output goes straight to your mixer.
If you’re a DJ or karaoke host using DisplayHUB, you can use RequestSongs.co at no charge. It lets your guests request songs from their phones — no app download required. Ask us about getting set up.
