Only sound through one speaker when using hdmi lead

[stressedred]

I recently installed a hitachi projector cp-ex250n to powered speakers. When i show picture through vga and audio into earphone socket on laptop everythings fine sound in both speakers. When i use a hdmi lead i only get sound through 1 speaker the powered side. Any help appreciated
Audio cables are audio out on projector to audio in on speakers

 

[americanaudiophile]

What happens if you connect the VGA and audio out of the PC to your projector (instead of the audio going directly to the speakers)?
If you don't get both channels then the problem is in the projector.
If you do then the problem might be the projector (try a different HDMI source and cable) or the PC (connect the HDMI to a TV - do you get sound on both channels?)