The Woofer Buying Guide is intended to help you select the correct woofer for your application. Woofers are sorted by size, enabling quick comparisons between possible options for your particular speaker system. Many woofers can be used in sealed or vented applications, though there is a trade off between enclosure size and bass extension. Look at the Xmax and sensitivity issues to get an idea of what the real-world performance of the woofer can be. The higher the XMAX, the greater the low-frequency output potential; the higher the SPL, the less amplifier power it will take to achieve a desired playback level.

The enclosure volumes and F3's are based on BassBox calculations of the drivers in unstuffed, undamped loudspeaker enclosures. These represent "optimum" volumes that can be adjusted in size according to the goals of the system. For example, a smaller than optimum vented box is often used for high-output, high-power applications, while for a home speaker will often use a larger than optimum vented box for maximum low-frequency extension. By damping the enclosure (particularly in a sealed box) the recommended enclosure size can be reduced by up to 25%.