The broadcast of low latency Audio over a Wifi connection requires a solid Wifi system to ensure clear uninterrupted sound quality. Poorer quality wireless access point (WAP) systems may not have the processor power at the WAP to send packets with the regularity that audio broadcasting demands. The term for a system where packets are not sent with sufficient regularity is a system suffering ‘Jitter’.
The Flexicast Wifi Audio system allows for a reasonable amount of jitter, however the greater the tolerance a system has to jitter the greater the latency it will suffer. Latency is the difference between when the audio is sampled at the TV and when the personal device plays that audio remotely.
If jitter and in turn latency becomes excessive, a viewer will notice the audio falling out-of-step with the video being watched. Once latency exceeds about 200ms (milliseconds) total lip-sync will be lost and customer enjoyment will begin to suffer.
The Flexicast WiFi Audio App has a slider that will allow a viewer to adjust the latency the app maintains. A low latency setting in a system where jitter is an issue will cause audio underruns (where the app is starved of the next peice of audio) which manifest as audible clicks or gaps in the sound output resulting in the perception of lower quality. The Latency / Quality slider of the app allows the customer to choose between stronger lip-sync at the expense of quality (if jitter occurs). If a viewer is say; watching a football match with commentary, lip-sync is probably not overly important so a viewer can opt for the quality end of the scale, however if a half time talk show comes on the viewer may wish to suffer occassional clicks in the audio quality to enjoy tight lip-sync.
A good quality WiFi system should be able to maintain a service with low enough jitter to allow a viewer to enjoy both strong lip-sync and clear audio at the same time. The default setting of the app’s slider is set to default to the best-case compromise, and the aim of the installation should be to install a Wifi system capable of acheiving a good result with the app set at the default position. Latency on Android hardware is slightly inferior to to that of Apple IOS devices so Andrid hardware should be used for testing of a completed installation.
Another consideration when choosing a Wifi host system is the “Concurrent Connection” capability of the access point and ensure it meets the venue’s requirements for the number of viewers they wish to service. While the Flexicast Wifi Audio server system can serve over 250 connections, a typical low-end entry point WAP might only have the ability to serve only 8 or 16 high throughput connections. Commercial grade access points (ie Ruckus, Ubiquity amongst others) can typically support hundreds of high throughput concurrent connections.
All-in-all money spent on a higher grade WAP will be money well spent as customers will have hassle-free enjoyment of audio in your venue.