Audio Engine support?

[obo]

I remember the (stalled) possibility of DTS downmixing in hardware, which would require a firmware update. Would using Audio Engine purely for pass-through still require firmware support?

If not, I might be tempted to have a hack myself. For personal use I could manage with just pass-through, but for general use it would be better to fall back to the existing sound system, if possible. If it's all a non-starter I'll wait until those who know the codebase better get to it