thavn:
That should do it. My Mac doesn´t have a HDMI, so my B&O dealer has ordered a HDMI expander where we shall use a DVI to HDMI + a separate phono signal to get both sound and vision. The DVI has no sound, but the HDMI does.
Which mac is it?? On never Macs, the headphone jack doubles as a digital output, so it's possible to get a surround output from it. But you might need an adapter to convert the mini-Toslink used in the Mac to digital coax used by B&O, ( if they still use these, they did on the Avant.)
You can also get a mini-displayport to HDMI converter if your Mac is less then a year old, such as this: http://gizmodo.com/5380669/mini-displayport-to-hdmi-adapter-with-digital-audio-review
These adaptors are also available where the audio is taken from the digital output instead of the USB port.