Speakers Explained
Speaker Sensitivity and SPL
Sensitivity is the most useful speaker spec almost nobody talks about. It tells you how efficiently a speaker turns power into volume — and it explains why watts are a poor guide to loudness.
What sensitivity measures
Sensitivity is usually quoted as an SPL figure at 1 watt, measured 1 meter away — for example, 96 dB (1W/1m). A higher number means the speaker produces more volume from the same power. The difference between an 88 dB and a 96 dB speaker is dramatic.
SPL and how loudness adds up
SPL (sound pressure level, in decibels) is how we measure loudness. The decibel scale is where intuition breaks down, so two rules are worth memorizing:
Why sensitivity beats wattage
Because power buys so little volume, a speaker's efficiency does the heavy lifting. Consider two speakers:
- Speaker A: 88 dB sensitivity, fed 100 watts.
- Speaker B: 98 dB sensitivity, fed 100 watts.
Speaker B is 10 dB louder — as loud as Speaker A would be with 1,000 watts. That 10 dB of sensitivity replaced a tenfold increase in power. This is exactly why professional PA speakers get so loud without absurd amplifiers.