bass reflex designs use energy from the rear of the speaker interacting with the volume of air in the port to give some additional efficiency over sealed box designs
Wayne Parham Messages: 18787 Registered: January 2001
Illuminati (33rd Degree)
You might notice the page where that spec is listed gives conditions where measurements were taken. All specs are given at 2.83v/M rather than 1w/M. The woofer is a 4Ω part, so 1 watt is dissipated with a 2.0v drive signal. Send it 2.83v and 2W is dissipated, which is 3dB higher.