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Mac (2009) digital output to Mbox2pro SPDIF input
Old 4th February 2015
Gear Head

Mac (2009) digital output to Mbox2pro SPDIF input


I have a digital cable running from my 2009 macPro (digital out via Toslink digi cable) to a powered converter to SPDIF cable into digital input on MBox2pro (channels 5&6).
Does the digital output from MacPro always send out audio
(ie. channels 1&2/L&R) by default,
or do I need to set this up somehow (aggregate device??) so I can listen to audio as usual from monitors connected to Mbox,
and get sound from digital output at the same time.
I am trying to set up SpectraFoo ( & prob Spectre in future ) to receive the audio via this method for analysis, but so far no luck...
Any help / tips would be very welcome.
Old 4th February 2015
I don't know much about Macs and some of the other things you mention, and I'm not quite sure if I'm understanding your question.... but I can say that s/pdif is a stereo signal, not multiple channels like say, adat etc. (if that is of some confusion for you?) I believe it's your audio card & DAW software that can determine which two channels you want to send that stereo signal out of, otherwise the default I would guess be channels 1/L & 2/R.

I use s/pdif cables between multiple PC's, via Aardvark Q10's in each machine. I use I think channels 9/L & 10/R of my sound cards to send my stereo signals...errr...I may be wrong on that actually...I think I just use 'channel 9' for both my In & Out on my s/pdif, as a digital coaxial RCA cable/connection caries 2-channels (L/R).
I've also used toslink cables between my Aardvark Aark 24 cards for multiple channels (8) which is much more work to set up, and since I only needed a stereo channel, I went to using that toslink for just stereo & no assigning multiple channels.

But going back to s/pdif in your case s/pdif is only capable of a stereo L/R signal. If I've understood what you're doing correctly...using a Toslink to some s/pdif conversion box, Toslink I think being capable of both multi-channel or a stereo channel, and s/pdif only being a stereo channel, you'd have to make sure you match up the Toslink & s/pdif on the same 2 channels...1/2, or 3/4 etc, etc.

Or...maybe I'm way off on what your question is...?

Last edited by Steve Fogal; 4th February 2015 at 04:22 PM..
Old 7th February 2015
Gear Head


MBox SPDIF out to converter to Toslink cable to MacPro built in digital input

AudioMidiSetup aggregate device -
MBox2pro + built in digital input

Logic Preferences > Audio > Devices = aggregate device

Logic Preferences > Audio > i/o assignements
Output = 7&8 (MBOX SPDIF)
mirroring box checked

Spectrafoo input channels = macPro built in digital in (7&8)

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