I have a first gen Airport Express (from 2008) and use it with Mountain Lion. The connection chain looks as follows:

MacBook Pro -> WiFi (802.11n) -> Airport Express (receives Internet via DSL cable) -> Regular solid state amp

It works fine in the following situations:

  • Spotify
  • iTunes
  • Quicktime video or audio
  • Youtube using the HTML5 trial on Safari
  • Chrome
  • Vimeo on Safari

However, there's a huge sync difference (to be exact: 2 seconds) between audio and video when I use:

  • VLC
  • Youtube, Vimeo (or any other video site) on Safari using anything but HTML5
  • Youtube, Vimeo (or any other video site) on Firefox

A work around for VLC is to delay the video channel by 2 seconds to make the audio/video line-up again. But the browser is not as easily fixed.

From reading around on discussion forums this seems to be a Mountain Lion issue. Does Mavericks solve the audio/video sync problem when playing videos in Safari (or any other browser)?

For completeness I tried out the rather strange suggestion of Wheat Williams of connecting my MacBook Pro directly to the Airport Express using an Ethernet cable.

There was no difference at all compared to connecting through WiFi. The delay on VLC (if uncorrected) and on Firefox remained. This means that the connections speed is not the bottleneck.

  • It probably has more to do with WiFi speeds than the Mac OS X version you are running. What is your complete signal chain? What model Macintosh are you using? What model Airport Express? What is it connecting to, a television, another Mac, something else? Are you using WiFi g or WiFi n on the Mac, on the Airport Express, and on the target device? Have you tried connecting your Mac to the AirPort Express using an Ethernet cable rather than WiFi? That will increase your video streaming throughput dramatically. – user9290 May 26 '14 at 21:06
  • The original Airport Express from 2004 is an 802.11 b and g device. Its WiFi signal is extremely slow by modern standards. No wonder any kind of high resolution video you are streaming is of lower quality and out-of-sync. The video that was online in 2004 was much lower resolution than the videos that are available online in 2014, meaning that a 2004 router is not fast enough for modern video. Now tell us about the other devices in the signal chain and their WiFi capabilities. – user9290 May 26 '14 at 21:13
  • I've added some clarifications. The delay is not dependent on WiFi speeds, it's set at 2 seconds natively. It works for some video formats in Safari, so it seems not to be a WiFi speed problem. – Saaru Lindestøkke May 26 '14 at 22:29
  • 1
    OK, fine, but what happens when you connect your MacBook Pro to the Airport Express using Ethernet rather than WiFi? I still say you need to get a newer 802.11n or 802.11ac WiFi router. Your old Airport Express with 802.11g and 10/100base T is not going to cut it. – user9290 May 26 '14 at 22:59
  • I'm confused as I don't see how the working programs (Quicktime and Safari+HTML5 and Safari+Vimeo) get around the the speed limitation, if that's the bottleneck. – Saaru Lindestøkke May 26 '14 at 23:14

You must log in to answer this question.

Browse other questions tagged .