The delay in sound from microphones when connecting a karaoke system to a television can occur for several reasons related to the characteristics and settings of the television, as well as the specifics of the connection and audio signal processing. Here are the main reasons:

Audio processing delay by the television (audio latency). Many modern televisions are equipped with digital signal processing (DSP) features that can introduce a delay in sound output. The television processes incoming signals (video and audio), which can cause a delay in the playback of sound from the microphone.

Audio and video synchronisation. TV may attempt to synchronise audio with video, especially when playing high-quality or high-definition content. If the television processes the video longer than the audio, it may delay the sound to maintain synchronisation between the video and audio.

Use of the "AV Sync" or "Audio Delay" feature. Some TVs have built-in audio delay functions ("Audio Delay" or "AV Sync") that allow users to adjust the audio delay time to synchronise it with the video. If this feature is enabled or incorrectly configured, it can cause a noticeable delay in sound from the microphone.

Delay on the karaoke system side. Some karaoke systems (particularly those that use digital audio processing) can introduce their own delay during audio signal processing. If the system then sends the processed signal to the television, and the television adds its own delay, the cumulative delay can become significant.

Wireless connection. If the karaoke system transmits sound to the television over a wireless network (such as Bluetooth or Wi-Fi), this can also cause a delay. Wireless technologies often introduce additional delays in signal transmission.

Use of HDMI-ARC or optical cable. If the karaoke system is connected to the television via HDMI-ARC (Audio Return Channel) or an optical cable, there may be a delay in transmitting sound to the audio system or amplifier connected to the television. The television may process the incoming sound before passing it on, resulting in a delay.

Television settings. Some televisions have different sound modes, such as "Cinema," "Games," "Sports," and so on. Some of these modes may process sound in a way that creates a delay (for example, to improve sound quality or add effects). Switching to a "Standard" or "Game" mode may help reduce the delay.

How to resolve the issue

To eliminate the sound delay from microphones when connecting a karaoke system to a television, you can try the following actions:

1. Check the television settings. Try disabling all sound processing features, such as "AV Sync," "Audio Delay," "Surround Sound," etc. Select a sound mode like "Standard" or "Game," which usually has minimal delay.

2. Connect the audio output directly to the audio system. If possible, connect the audio output of the karaoke system directly to an external audio system or amplifier, bypassing the television. This will help avoid any delay introduced by the television.

3. Use a wired connection. If you are using a wireless connection to transmit the audio signal from the karaoke system to the television, try switching to a wired connection (such as using analogue audio cables).

4. Update the firmware of the television and karaoke system. Sometimes, manufacturers release firmware updates that can improve device compatibility and reduce delays.

5. Check the karaoke system. Ensure that your karaoke system is not introducing its own delays during audio processing. If it has audio delay settings, try reducing or disabling them.

Following these recommendations can help reduce or eliminate the sound delay from microphones when connecting a karaoke system to a television.