Hi DE

Welcome to the forum. Is the X-box giving a proper two channel output into any other equipment? Do you have any other amp, set of PC speakers, etc which you could use to verify the output?

Does the X-box have an optical digital output which you could configure on the G91 instead? If it does, that would actually be preferable anyway.

I don't have a G91 myself, so can't offer first hand advice, but it does sound like a configuration issue. The best option is to try to borrow an old laptop from someone to properly run Mconfig. If you think that you will be increasing your Meridian kit in future, buying an old laptop is definitely a good idea.

Cheers

George