John Liddard writes: "I recently purchased and G4 Cube and Harman/Kardon iSub subwoofer. Simply put; these two devices do not work together. After speaking with Harman/Kardon technical support it was indicated that the stand alone iSub will not work with the G4 Cube because of the nature of the Cube's standard audio system. The G4 Cube comes standard with the Harman/Kardon "orb" speakers which are a USB audio device. The Tech support rep indicated that the Cube supports only one USB based audio device. Harman/Kardon's solution is to use the SoundStick product. This is a complete USB based audio sound system which includes two satellite speakers and the iSub subwoofer. This entire system acts as a single USB audio device which thus works with all USB based Macintosh systems." To be fair, Apple makes it clear that the iSub is only for use with the iMac. Still, we thought this more detailed information was of interest.