Bass Reflex Port

A bass reflex port is a tuned opening in a speaker cabinet – usually a plastic or wooden tube. The port converts rear-radiating woofer energy into forward-firing bass at a specific frequency (called the tuning frequency).

Ported vs sealed

• Ported – deeper bass extension for a given cabinet size, higher efficiency, but slightly less tight transient response and can bloat if placed too close to a wall
• Sealed – tighter, more controlled bass but rolls off higher, needs more power for equivalent SPL

Placement tips

Rear-firing ports (most common) need 4-8 inches of space behind the speaker. Placing rear-ported speakers against a wall boosts bass but adds boom. Front-firing ports (like some Klipsch designs) are more placement-flexible.