I just got the new "kinect ready" 4GB Xbox 360 and I have it hooked up to my computer monitor via an HDMI cable (no actual TV). However my monitor has no built in speakers, hence no sound. Looking at the back of the xbox it looks like the only way I can get sound is to try and run a SPDIF-to-RCA converter from the xbox into my audio mixer.
The AUX cable that comes with it has the RCA connections on it, but its got a plastic bit on it that prevents it from being plugged in at the same time as the HDMI cable (assuming that's intentional), so I can't try and use that for audio as-is.
I guess my question is: Is buying a SPDIF-to-RCA converter my best bet for getting sound in this situation?
Edit 1: Monitor: SAMSUNG BX2431 LED (via newegg)