Sound Output to both USB and Optical simultaneously in 10.4 on G5?

WOW! Not one single idea on this?

Thanks for the link DPcheck! I've got some reading to do.

Success.

But I would appreciate others testing this method.

Excuse the cut and paste: Formatting will be a little off.



Maybe I was a bit hasty in my conclusion that the AU_Lab application did not provide acceptable dual output -it was 3am! The other day I started over and created another AUL setup file. I NOW HAVE AUDIO STREAMING TO 2 DACS. I've been switching back and forth with and without AUL for 2 days trying to determine if there is any audio disortion. I am not 100% sure. I hope someone else will try to run AUL to give an opinion on any audio degredation (AUL works with just one DAC connected as well)

These are the programs I used:

* Soundflower - audio pass-through utility http://www.cycling74.com/products/soundflower (freeware)
* AU Lab from Apple application development tool kit – Xcode 2.5 download http://developer.apple.com/tools/download/ or from "Developer Tools" from your Mac OS X Install disc (free/registration required)
* Audio Switcher 1.2.1 http://tc.versiontracker.com/product/redir/kind/0/db/mac/id/33570/ (freeware)

Though not meant as a Multiple output tutorial his article: http://www.macosxhints.com/article.php?story=200504261547021 along with one other I lost, helped me set up AUL to have "Dual Output" to my two DACs. I must say that macosxhints.com is where I feel like I am treading water wearing 25lb weight belt. I am no Mac expert. Either ignore or embrace one of the "fun things" to do with AudioUnits: simulated Quadrophonic sound. So, essentially, I just followed the process and added one additional Output.


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IMPORTANT!: Make sure your amp/speakers/ volume is set very LOW while performing this procedure. If an error is made in settings, channels can be fed into one another and cause feedback which MAY damage your speakers. TURN VOLUME DOWN NOW.



PROCEDURE FOR SOUND OUTPUT TO MULTIPLE DIGITAL DAC DEVICES: APPLE POWER MAC G5 / OS X 10.4

Here is my modification to macosxhints.com "Fun with Audio Units" procedure linked to in the post above.

* Install the Soundflower application. This app passes through audio. A computer Restart may be needed.
* Install Apple's Developer Tools
* Open up Audio Midi Setup (in /Applications/Utilities). In the Audio menu, go to Open Aggregate Device Editor. This lets you combine audio streams together but presenting itself as a single device to the computer
* Create a new aggregate device, give it a custom name ("Multi-Outputs" will be used in the following steps) Under "Structure:" Drag the Audio Device name so that Soundflower(2ch) is on the top. Also Check Clock for this device. The next device is the Built-in Audio, then your USB device. Check the "Use" buttons for each Device you want. Choose "Done"
* In the AMS, Set the "Default Output" dropdown to the newly created Aggregate Device (Multi-Outputs). Now you won't hear sound playing through at this time.
* Open up the AU Lab application over your top level folder computername/Developer/Applications/Audio.
* Create a new document. Use these settings:
o Audio Device: "Multi-Outputs" (or your custom device name).
o Outputs tab: Drag the red box to the Stream 2 (#3/#4)
o Outputs tab: Click the ➕ Add Output button and drag the new red box to the Stream 3 (#5/#6)
o Inputs tab: Click the ➕ Add Input" and drag the red box to "Soundflower Input Stream #1" (#1/#2), if necessary. Click OK.
You should now be able to hear sound. But from both outputs?
* One more thing: In the AUL control panel: Highlight both #1 and #2 boxes in the Volume tab section, located at theleft side of the cantrol panel. Now Save this file. The saved file must be used to have this work again. Make a script/automator action to automatically open it, if desired.
* No other settings are adjusted in AUL.
* I did get a couple "CPU Overload" error messages in the AUL window, which did not interrupt music or change the sound.


I use Audio Switcher on the menu bar to easily choose from my custom Aggregate Device (used for Multi-Output) or the standard Devices. I've been using some very simple vocal tracks and even a constant frequency signal audio file to compare AUL vs direct to USB. During that switch there is a "snap" sound when toggling so it is a bit tough to hear "side-by-side." At least now I know that computer is capable of sending to multiple outputs. The analog ports also are outputting sound during the AUL session.

Cheers, ed

Message was edited by: ejc3

OK maybe this Doesn't work. With sound being sent to both outputs using the settings above, after a few hours of playing one output is very distorted (SPDIF) while the USB DAC is fine. hmmm?