Watts on a speaker or amplifier spec sheet: what the FTC's power rating rule has required since 2024

Wattage claims for home audio gear have been regulated for more than 50 years: the Federal Trade Commission's Amplifier Rule dates from 1974. Amendments that took effect on August 12, 2024, fixed the test conditions behind a power claim and added labels that separate a figure measured the FTC's way from one that was not. This guide explains what the rule now asks of sellers of amplifiers, receivers, powered speakers and similar gear, and what it does not cover.

Why the FTC changed the test

The rule has always required a power claim to rest on standard test conditions, but before 2024 it did not fix values for three of them, the speaker load, the range of frequencies and the level of distortion allowed, and required sellers to disclose their choices instead. The FTC's own examples show why that mattered. When it first wrote the rule, it had evidence that the same amplifier might produce 20 watts if driven to 0.5% distortion and 30 watts at 5%. Its 2024 notice also gives the example of an amplifier that might put out 550 watts into 2 ohms but only 215 watts into 8 ohms.

The FTC says its staff found dozens of examples of the same equipment advertised with very different power figures, and used manufacturers' own spec sheets to trace the gaps to different test settings. The Commission concluded that disclosing the test conditions alone would not help most buyers, because converting the figures into a like-for-like comparison is too technical, and it noted that people now shop online more, with fewer chances to listen before buying. Its review drew 550 comments responding to the 2020 notice that opened it, and all but one supported keeping the rule.

What an “FTC Power Output Rating” has to mean

Whenever a claim is made about power output, power band or power frequency response, or distortion, the manufacturer's rated power output must be disclosed, labeled “FTC Power Output Rating”. That rating must be shown clearly, conspicuously and more prominently than any other representation or disclosure the rule permits, and it may not be made by a footnote, an asterisk or a similar notation. The current test conditions are set out below.

The FTC first proposed a distortion limit of 0.1% in 2022. After commenters said many tube and solid-state amplifiers could not qualify for any rating at that level, it settled on 1.0% THD+N. The multichannel requirement formalizes the FTC's 2010 guidance. As we read it, a per-channel figure for a surround receiver measured with only one channel driven would not qualify as an FTC Power Output Rating.

Other figures must be labeled

Makers can still publish ratings measured under other methods, including international standards, as optional disclosures. Each such figure must be expressed in minimum watts per channel and labeled “This rating was not tested under the FTC standard”, again without a footnote or asterisk. It must also be less prominent than the FTC rating: under the rule, a figure in bold or more than two-thirds the height of the FTC rating does not count as less prominent. The method behind it must be well known and generally recognized in the industry, and neither intended nor likely to deceive or confuse consumers. The FTC chose that wording over its earlier draft, “This rating does not meet the FTC standard”, to meet a concern from the Consumer Technology Association (CTA) that the draft denigrated accepted international standards.

Separately, the rule bars any claim about a covered performance characteristic that the equipment cannot deliver when a consumer uses it normally, without extraneous aids. Another seller, such as a retailer, that passes on a manufacturer's figures is not in violation of that provision if it has the manufacturer's written certification that they are accurate and has no actual knowledge that they are wrong.

What the rule covers, and what it does not

The rule applies to sound amplification equipment made or sold for home entertainment, and its own examples are radios, record and tape players, component audio amplifiers, and self-powered speakers for computers, multimedia systems and sound systems. The FTC's 2022 proposal, as its 2024 notice describes it, would have required amplifiers in self-powered full-range loudspeakers, such as full-range Bluetooth speakers putting out more than two watts, to be tested across 20 Hz to 20 kHz. The final text keeps a narrower band only for subwoofer amplifiers in multi-amplifier systems.

There are two important limits. Claims are exempt when every one of them clearly and conspicuously discloses a manufacturer's rated output of 2 watts or less, per channel or in total. And the rule applies only when a seller makes a power-related claim. The FTC said in 2024 that a manufacturer that does not want to follow the standard need not make such a claim. As we read it, a speaker or soundbar whose maker states no power output, power band or distortion figure is outside the disclosure requirement.

Where the rule stands now

In October 2024, the FTC published a petition from CTA asking it either to clarify how the amended rule applies or to amend it so that it covers only products designed, tested and manufactured on or after August 12, 2024. Comments were due by November 8, 2024. When we searched the Federal Register's database on November 10, 2026, we found no later document on the petition: a search for the rule's title in documents published since October 10, 2024, returned none, and a search of FTC documents mentioning amplifiers in that period returned only the agency's August 2026 regulatory agenda. The FTC's regulatory agenda of August 14, 2026, lists the Amplifier Rule among its current rulemakings likely to have some impact on small entities, though the agenda says no final decision on the need for or substance of a rule should be inferred from it. The eCFR text on November 10, 2026, shows the 2024 amendments.

Watts are only one line on a spec sheet. Our Sonos and Bose soundbar comparison covers the specifications those two makers publish for six soundbars, and our guide to headphone volume limits covers a different kind of audio figure.