Audiophilepure

https://www.stereophile.com/content/pearl-acoustics-model-one-loudspeaker

The driver is only half the equation; the Model One’s cabinet, based on the Voigt pipe design, is the other half. In a conventional speaker enclosure, the rear soundwave cancels the sound produced by the front of the cone. In a Voigt pipe, the rear wave is delayed so that it exits the enclosure in phase with the front wave, which it does through the vent at the base of the baffle. “The two waves reinforce each other, increasing acoustic output,” explained Harley. “Especally in the lower bass region.”Another characteristic of the Voigt pipe design is its tapered internal geometry, which works much like a horn or an acoustical instrument. Harley: “Consider the double bass. When a player plucks a string, the vibration travels down through the bridge into the front of the body of the instrument. The front panel excites a large volume of air, which escapes through the small f-holes, producing loud and powerful low frequencies.”The Model One operates on a similar principle,” he said. “The energy from the rear of the driver excites a column of air inside its enclosure. That air is then released through the front port in a controlled manner, allowing the system to produce very deep and well-defined bass from a relatively small initial movement.”