I have an Apogee Duet firewire audio interface that gives me one stereo channel in and out. It works great for single track recording and overdubbing but is not very functional for dj’ing. A great feature available in OSX is the ability to create aggregate audio devices. What this means is that you can use both the external audio interface and the built-in audio device in your Mac at the same time. This allows you to cue on one channel (the built-in 1/8″ mini-jack output) and send out to the main outputs on another (in this case the Duet).
Aggregate Device Editor
To accomplish this, open Audio MIDI Setup under Applications->Utilities. In the Audio MIDI Setup menu bar, select Audio->Open Aggregate Device Editor. Click the + button to create a new aggregate device and then in the Structure window select which devices you want to include. As an example, I selected the Duet and the Built-In Output and made sure that the Duet was in charge of timing by clicking the radio button next to it. Now in a program such as Ableton Live you can use both the Duet and the Built-In Output at the same time allowing you to cue loops and tracks before you bring them into the main mix.
You could also create other aggregate devices to allow recording on both your Built-In Input and your external device inputs but be warned that the recording quality may vary between the two devices.
I heard that in Ableton Live, aggregate audio devices using the Duet are producing too much latency. Have you heard anything about this? Either there’s a lag between the System Audio and the Duet (firewire) or the two simply add up to unusable measurements of latency-I can’t tell you cause I haven’t tried it. Does creating an aggregate audio device put more effort in the CPU?
I have an alternate Duet set-up whereby I’ve set-up two mono outputs in the live audio preferences pane, and omitted a grouped Stereo output. I simply put my Master through Output 1 and my cue through output 2 (and make sure the solo buttons, audiofinder etc are set to “cue”). For really stereophonic information, I think I’m actually even safer to keep things mono in a club because proximity effects wouldn’t make much sense for folks standing in different locations of a club, and many PAs are set-up in mono to begin with.
My follow up question to you-when ableton states that selecting and deselecting i/o channels will effect CPU load, do they also count the mono’s and stereo pairs as separate channels?
Thanks,
James
Hi James,
Yes you will definitely have increased latency when using the aggregate device. The onboard output is the proverbial weakest link in the chain that slows the whole thing down. That said it doesn’t slow it down that much for me. It is certainly workable. I suggest using the test tone in Ableton Live’s preferences to test the difference between the Duet on its own and as an aggregate device with the onboard output to figure out if it will work for you.
As far as your second question I don’t know the answer for sure but I suspect that two mono channels on the Duet would take roughly the same amount of processing as a stereo channel.
Cheers – Jason
u r the maaaaaaan!!!!!! now i wont sell my duet anymore
thx a lot dude!!!!!!!
You’re welcome. Glad to have helped.
so in the ableton settings what do i set things to as have tryed what you said but hear nothing through the headphones?
Hi sean,
In Live go to your audio preferences and set your Audio Input Device and Audio Output Device to the aggregate one you just created. Then in the Session view make sure that you can view the I/O, the button to do so is on the far left. Then on the Master channel set the Cue Out to whatever channel you want to use for your headphones and set the Master Out to whatever you want it to be.
Let me know if you are still having problems.
yes its working thanks for your help, do you know how to scan afor a midi controller which isnt in the ableton midi list? ive just bought a novation nocturn which i can not seem to assign to anything