Things to Keep in Mind When Measuring Audio Latency of Receivers
Receivers have a lot of settings and each of these settings can impact audio latency. Here are some notes you should keep in mind when testing audio latency of a receiver:
- Receivers can often have drastically different latency based on the input signal. It’s a good idea to test different input signals such as 2.0 stereo and 5.1 surround over HDMI.
- Both a Yamaha and Sony receiver that I tested had over 40ms longer audio latency when processing an HDMI stereo signal compared to an HDMI surround sound signal.
- A receiver’s “Speaker Distance” setting affects audio latency. Speakers that are a closer distance will have a delay applied to them to make all speakers’ sounds reach the listener at the same moment. When testing, it’s important to set all of the speaker distances to be equal so no delay will be applied to any of the speakers.
- Automatic speaker calibration such as Audyssey or Accueq will adjust speaker distances, so you should expect this to add a delay to some or all speakers.
- Equalizers, such as those that are activated by speaker calibration like Audyssey or Accueq, may introduce an additional audio delay. The “Direct” sound mode can be used to disable equalizers.
- When no equalizer is active, the “Direct” sound mode often does not reduce or increase audio latency for an HDMI signal but often does reduce audio latency for an analog signal. It’s a good idea to test different sound modes to see which affect latency.
- In my initial tests, only one of six different brands had reduced audio latency in Direct mode with an HDMI signal. Conversely, four out of these six had reduced audio latency in Direct mode for an analog signal.
- A receiver’s “auto lip sync” feature enables reading of EDID or CEC messages from your TV to add a delay to audio to match your TV’s video latency. Most receivers also have a manual audio delay setting for lip sync. When testing the audio latency of a receiver that may be used by a consumer with a TV that does not have auto lip sync capabilities:
- The manual setting should be set to zero.
- If you have the receiver connected to a TV that may be communicating it’s auto lip sync delay the receiver’s auto lip sync setting should be turned off.
- Most receivers will have a different latency for an analog signal compared to an HDMI signal, so testing with an analog signal can be useful.
Last updated on July 12th, 2021.