The major difference is the size, and consequently the driver and amp configurations, which then dictates the sonic performance and audio experience, making these speakers suitable for different room sizes and varying loudness. Most of the connectivity and controls are the same across the models, with the exception of Acton, which doesn't have RCA input though, and Woburn, which is the only model in the family that comes equipped with a HDMI connector, making it more convenient to use with a TV.