A baffle prevents acoustic short-circuiting when it makes air travel farther

Evidence

Whenever a compression region is so close to the rarefaction region that air can flow from one to the other within half a period, the pressure difference will be partially canceled by short-circuiting. If a big enough barrier is put up to make the air travel farther, the cancellation is prevented. This is the principle of the baffle. The law of similarity makes it clear that lower frequencies need a larger baffle. — Eric J. Heller, Why You Hear What You Hear- An…, 618

Categorization

• DEFINE: Explains the acoustic short-circuit mechanism and the baffle principle clearly.
• XREF: Connects to loudspeaker engineering and the law of similarity from previous chapters.