Navigating the world of AV systems often means grappling with some challenging terminology and concepts. To help make sense of this world, we have teamed up with Will Gregory, AV & IT Technician at Fitzwilliam College to bring you a series of blogs designed to demystify AV for events. In this first post, we’ll break down some of the key AV terminology and concepts you need to know:

 

Acoustic Treatment

This involves modifying a room’s acoustics to enhance sound quality. Techniques include adding materials to absorb or reflect sound, but the specifics can be complex. Acoustic treatment helps manage sound reflections and echoes, improving audio clarity.

 

Aspect Ratio

This term describes the proportional relationship between the width and height of a screen or image. Common ratios include 4:3 (standard definition) and 16:9 (widescreen). The aspect ratio affects how visuals are displayed; for instance, a 16:9 screen is suited for HD content, while a 4:3 screen might distort widescreen content or leave black bars on the sides.

 

Audio Delay (Lip Sync)

Audio delay occurs when the sound is not synchronised with the video, making it appear as though a speaker’s lips are uncoordinated with their voice. This issue often arises due to processing delays in digital systems, especially when multiple devices like cameras, projectors, and sound systems are involved.

 

Audio Equalization (EQ)

EQ adjusts the balance between different frequency components of an audio signal. This process affects how sound frequencies are amplified or reduced, impacting the overall sound quality. Proper EQ ensures that audio is clear and balanced, but it can be complex to adjust correctly.

 

Bandwidth

Bandwidth refers to the amount of data that can be transmitted over a network in a given time. When live streaming events, sufficient bandwidth is crucial to deliver smooth, high-quality video and audio without interruptions, buffering, or dropped frames. The more data your stream requires, for example high resolution, fast frame rates, or a number of streams, the more bandwidth you will need.

Minimum Bandwidth for High-Quality Streaming

To stream in high-definition (HD) quality, the following are considered the minimum bandwidth requirements:

  • 720p (HD): At least 3-5 Mbps (megabits per second) for smooth video and clear audio.
  • 1080p (Full HD): At least 5-10 Mbps, especially if the stream involves fast-moving visuals or multiple camera angles.
  • 4K (Ultra HD): Streaming in 4K resolution requires at least 25 Mbps for high-quality, uninterrupted playback.

These minimums ensure your audience experiences a smooth stream without constant buffering. However, actual needs may vary based on factors like the complexity of the stream (e.g., multiple streams or screens) and the type of content being broadcast (e.g., presentations versus live performances).

 

Latency

Latency is the delay between the input and output of a signal. In AV contexts, this could mean the time between a speaker’s action and when it’s heard by the audience. High latency can affect real-time interactions, such as live streaming or video conferencing, where synchronisation is key.

 

Resolution

This refers to the detail an image holds, measured in pixels. Higher resolution means sharper and more detailed images. For example, 1080p (Full HD) has more detail than 720p (HD). Resolution is crucial for clarity, especially in large displays or close-up viewing.

 

Signal Conversion

Sometimes, you need to connect devices with several types of input or output. Signal conversion involves translating one type of signal into another, such as HDMI to VGA. This is necessary for compatibility between various pieces of equipment.

 

Signal Flow

Signal flow is the path that an audio signal takes from its source to the output. Your AV team will be managing and monitoring this to make sure your AV is seamless.

 

Signal Routing

This involves directing audio and video signals from various sources to their destinations. For example, a signal routing setup might send audio from a microphone to the speakers and video from a computer to a projector. Proper signal routing ensures that your equipment communicates correctly, and your event runs smoothly.

 

Streaming: Event Industry Standard

For professional events, the industry standard is typically 10 Mbps for 1080p streaming, which provides a good balance between quality and reliability. This ensures the stream remains stable even in environments with fluctuating network conditions or when several users are accessing the stream simultaneously.

  • Dedicated Internet Connection:

For large events, it’s common practice to secure a dedicated, wired Internet connection to ensure consistent bandwidth availability. Relying on shared Wi-Fi can lead to reduced quality, as the bandwidth can be affected by other users on the network.

  • Backup Streams:

Many event professionals use backup streams at lower resolutions (e.g., 720p) to ensure that, if there are bandwidth limitations, the stream can automatically downgrade to a lower quality instead of cutting out entirely.

By ensuring you meet these bandwidth standards, you can deliver a seamless streaming experience that enhances audience engagement, both in-person and remotely.

 

Is there a term or concept we've missed? Let us know here and we will add it to this page!

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