When connecting 4 speakers to the RoadGear, the total loading for each power amplifier channel should not be lower than 4 ohms. Therefore, the impedance of each speaker should be 8 ohms or greater.

The two RoadGear speakers can be used in this case, as well as 2 other 8 ohm speakers. As for sound quality, of course the signal sent to each speaker will be slightly diminished, however the clarity should not be affected at all. If anything, with the output of four speakers, the sound quality improves slightly.