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Sound Pressure Level
Definition: SPL (Sound Pressure Loudness) is the amplitude of an acoustic wave stated in "dB" that is proportional to the logarithm of its intensity. The decibel (dB) is a logarithmic unit indicating the ratio of a physical quantity or intensity relative to an implied reference level.

Explanation: The RATS SPL number is generated using a Sine Sweep and represents the subwoofer system's loudness once installed in the vehicle. A Sine Sweep is more accurate when analyzing high SPL frequencies as well as pinpointing the Resonant Frequency of the vehicle. The Resonant Frequency is the point at which a system tends to oscillate with a larger amplitude.

What To Look For: Look for the difference in SPL, not necessarily the biggest number. The difference in SPL is especially important when comparing different woofer sizes or alternate amplifier power. A 1dB difference is typically the smallest perception in loudness change with a 3dB difference being the most notable change. To increase a system's loudness by 3dB requires you to double the subwoofer Sd (effective cone area) or double the Pe (amplifier power).
Sample Sealed SPL Sample Vented SPL
• Written by Eric Russell.