I think you should be able to leave your computer set to automatic, and it should figure out a local link IP address for itself (you may need to reboot the PC without the cable modem connected so it doesn't give you an IP address), you can also leave the Empeg set to Automatic configuration (Player configuration, networking and you have to be connected via serial or USB to set this) and it should also get an IP address in the same range.

When opening Emplode select network broadcast under the options meneu, and hopefully it should find the Empeg.

If it still doesn't work you could see if anything in the FAQ helps.