Your math is Ok, but 90 dB is not the starting point for your dynamic range. Dynamic range is the difference between the softest and the loudest, and 90 dB is pretty loud to start with. 120 dB is EXTREMELY LOUD, equivalent to a jet taking off. 140 dB is the threshold of pain. Your million watt amplifier producing 160 dB would destroy your hearing. A more reasonable 60 dB range would be 40 to 100 dB, well within the capabilities of most hi end amplifiers and speakers.

Speaker efficiency vs. power requirements

Recently someone gave me the "math" behind speaker efficiency ratings and power requirements. Although I am not sure if the information below is 100% accurate, it is what I have been told. Can we lay this on the table for discussion and try to resolve this confusing issue once and for all?

0 db is a power ratio of 1. Records and tape have dynamic ranges of 30-40db. To achieve a 30db dynamic range requires a power ratio of 1,000:1 and 40 db requires 10,000:1. So if you assign 1 watt of power to a speaker yielding 90db SPL, you need 1000 watts to deliver a true 30db dynamic range. With digital material we find dynamic ranges of 60-70db requiring power ratios of 1,000,000:1 & 10,000,000:1 respectively. Power amps of 1-10 million watts are not feasible today but the point is, more power offers more dynamic realism. Forget power vs. loudness because that really is not a factor in the overall scheme.

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- 13 posts total

- 13 posts total