If your speakers all belong to the same "family," meaning that they're made by the same manufacturer and belong to the same speaker line, then you should be covered. Voice-matching simply means that the separate speakers you choose have the same timbre or tonal quality. This is essential if you want seamless, convincing sound. For example, you wouldn't want a car to sound different in your surround speakers than in your front speakers -- it would be distracting. Voice-matched speakers ensure that what you hear sounds the same in your front speakers as it does in your back, giving you the most engaging, movie theater-like experience possible.