Twice

i'm working on an ambisonic patch with Max and after troubleshooting for quite a while I can't figure out how to send signal to 14 loudspeakers through two audiocards. The audio cards daisy chained/linked by firewire to my MacBook, a Motu UltraLite and a Motu 828mkII. In the past i've managed to get sound sent to half of the speakers (the 828 half) or if I set the ultra lite as the main card, the sound is sent to the other half of speakers, but never all of them at the same time. Can anyone offer any guidance/suggestion with this?

Aggregate device - 2 8in8out sound cards, 14 loudspeakers - MaxMSP...help?