FTC to Require Amplifier Power Ratings Based on ‘Uniform Testing'

The FTC is seeking comment on a proposal to update its 1974 amplifier rule by requiring sellers that make power claims in marketing amplifiers for home entertainment products “to calculate power output using uniform testing methods to allow consumers to easily compare amplifier sound quality,” said an NPRM released Tuesday. Comments will be due 60 days after the NPRM is published in the Federal Register.

“Numerous commenters” in a 2020 Advance NPRM urged the FTC to require uniform power band, load impedance and total harmonic distortion limits for measuring amplifier power output -- metrics that were left out of the 1974 rule, said the NPRM. The commission counted 173 commenters who proposed standardizing testing with at least one of these specs: (1) A load impedance of 8 ohms; (2) A power band of 20 Hz to 20 kHzand (3) A THD limit of less than 0.1%.

Commenters “generally asserted that uniform test conditions would address consumer confusion resulting from advertising of unrealistic power outputs,” said the NPRM. FTC staff “found this problem was ubiquitous in the marketplace,” it said. Staffers “found dozens of examples of the same equipment advertised with significantly different power output,” it said. “Using specification sheets on manufacturers’ websites, staff confirmed these widely divergent output claims result from different testing parameters.”

Consumers “are unlikely to understand the complex power output disclosures marketers are making” under the current amplifier rule, said the NPRM. “The problem is amplified by the fact that consumers now shop online more frequently, providing fewer opportunities to listen to equipment before purchasing it,” it said.

The existing rule requires manufacturers “to fully drive all ‘associated’ channels to the rated per channel power when measuring the power output of sound amplification equipment designed to amplify two or more channels simultaneously,” said the NPRM. The introduction of home theater equipment with five or more channels “improved consumer amplification choices but raised questions regarding which of these new channels were ‘associated’” under the rule, it said.

Of commenters who advocated “driving the three front channels to full rated power and all other channels to one-eighth rated power,” those comments “did not provide evidence that these parameters approximated normal use,” said the NPRM. The commission wants to know which channels in a multichannel amplifier typically are fully driven "simultaneously during normal usage,” it said.

The FTC also asks which channels in a multichannel amplifier are "partially" driven during normal usage, and "how hard such amplifiers drive these channels?” said the NPRM. The FTC also wants comments on which test procedures “would best measure multichannel amplifier power output during normal usage?”