Streaming Audio Between Macs

Airplay you say? Between Macs, not an Airport Express or Apple TV. Airtunes you say? Well… I’m watching videos and streaming the audio to a different computer because it’s connected to the awesome speakers. And the lag… 2.5 seconds. Seriously.[1] Shairport? Same problem. Banana TV? Abandoned. And they have audio quality issues. And I could run down another half dozen systems that didn’t even work.

So, Mac to Mac, audio only. Fortunately, a friend of mine dug up this blog, which links to another blog that no longer exists. But it does provide a high-level overview, and I’m here to bring the step-by-step back.

Things you’ll need:

Sending Mac

  1. Install Soundflower (and reboot) and AU Lab
  2. Set System Audio to Soundflower (probably 2 channel) (System Preferences -> Audio -> Output)
  3. Run AU Lab
  4. Under the Stereo In/Stereo Out configuration, set the Input to SoundFlower and the Output to Built-in Output. Create document
  5. Under the Output, there’s an Effects dropdown. Set that to AUNetSend. Optionally configure a name, port, or password. Also, select Audio Quality. Both of my computers are on a gigabit LAN, so I’m streaming 24 Bit Apple Lossless with no problems.

Receiving Mac

  1. Run AU Lab
  2. Under the Stereo In/Stereo Out configuration, set the input to None and the output to Built-in Output. Create document
  3. Go to the “Edit” menu (as in menu bar) and select Add Audio Unit Generator. Choose AUNetRecieve
  4. In the new window, the share name you created earlier should appear. Select it and press Select Host and then Connect. If “Status” is “Connected”, you can close this window (you can bring it back by selecting the Generator and going to Edit -> Edit Selected Generator)
  5. Make sure the window with your Generator and Output says “Audio Engine Running” at the bottom. If it doesn’t click it to start it

Bam! High quality, low latency audio streaming between Macs. Rock out :)

Update

This solution seems to accumulate lag too over several hours :(. No idea why. Resetting the AUNet connection from either end resolves it though (on the sender, you can edit the AUNetSend effect and click “Disconnect” and then “Connect” again). It should last through a movie at least. Well… maybe not LotR extended edition…


[1]Support says they’ll be rewriting the audio subsystem eventually. After they do something with Windows…
Thanks to this site, which got me most of the way here

About Bion

I'm a software developer at Modo Payments, a mobile payment provider. When I'm not hacking away the office, you I'm usually at home hacking on something else. Or practicing Aikido. Anyway, I just post things here that Google couldn't help me with, so maybe it'll help you in the future. Since you're reading this, I guess it worked :)
This entry was posted in Technology and tagged . Bookmark the permalink.

9 Responses to Streaming Audio Between Macs

  1. Steven says:

    awesome post you have here. exactly what i needed to stream audio from one mac to another. thanks! :)

  2. This solution is awesome, and solves a very unusual problem for a friend of mine. My buddy Slau owns his own recording studio, and happens to be blind. He needs to be able to run Apple’s Logic from a remote Mac using screensharing, but the audio from VoiceOver doesn’t come through when connected via the vmc protocol. I tested out your solution using Soundflower and AU Lab, and it worked perfectly. He’s asleep right now so doesn’t know I (with your help) cracked the code on this, can’t wait till he wakes up and reads how to do it!

    By the way I’ll be talking about this on my podcast this Sunday and I’ll give full attribution here – but I was hoping to call you out by name too. I couldn’t find any attribution and perhaps that’s intentional so no worries if you don’t want your name used. Anyway, thanks for posting this – giddy with excitement that it worked!

    Allison Sheridan
    NosillaCast Mac Podcast at http://podfeet.com
    A technology geek podcast with an EVER so slight Macintosh bias!

    • Bion says:

      Awesome, glad it helped! And don’t worry about attribution (although my name is on the page :P) – it’s nice to know somebody reads this :)

  3. vurt1984 says:

    thanks! very handy !!!

  4. Josh says:

    Thank you for this! I recently had a baby and needed a way to remotely mix Pro Tools sessions from my living room while the baby slept. This AU Labs/Soundflower audio solution along with Screen Sharing made it possible. I’m going to share this blog with my friends at Pro Tools Expert. Thanks again.

  5. Samm1277 says:

    Thank you so much mate, I swear it should be so much more simple to stream audio from one mac to another but apparently not! Thanks :D

  6. Dan says:

    Hello,

    I have made it to the final hurdle and then faltered. On stage 4 of the receiving mac instructions the share name doesn’t come up. I have tried hitting the plus sign and adding my own port/user name and password but when I hit connect it just gets stuck trying to connect. Any ideas why this may be?

    Thanks in advance.

  7. Pingback: #453 Dot Me Domain, Mac Boot Up Key Modifiers, Enable Remote Mac Screensharing Audio, PortraitPro, Taming the Terminal 14 « NosillaCast

  8. John Baker says:

    Still useful, after all these years….

Leave a Reply to Steven Cancel reply

Your email address will not be published. Required fields are marked *