About the seemingly greatly exaggerated power specs on most Chinese class D amps. Texas Instruments provides detailed specs on each of their amp chips. But, it seems they also condone giving amp manufacturer's a lot of leeway on how they describe this power in advertising.
See this TI report on Amps and Advertised Power ratings.
On page 4 they conclude:
The need for attractive marketing strategies requires TI customers to devise creative ways to use power rating for advertisements.
This paper assists TI customers in determining the suitable power rating to be used in the advertisement of their products. TI supports customers internationally and understands that each region of the world requires different marketing strategies. While the power rating for the US market is dictated by the FTC, other countries may not be restricted to such requirements. In those cases, TI customers are open to choose the acceptable power rating for advertisement. As mentioned in the introduction, PMPO generally is not well-defined and accepted as an audio performance measurement. It is used mostly for advertisements.
The report was written in 2005. The FTC has not enforced power rating standards in the U.S. for more than 10 years...so that restriction seems quaint now.
See this TI report on Amps and Advertised Power ratings.
On page 4 they conclude:
The need for attractive marketing strategies requires TI customers to devise creative ways to use power rating for advertisements.
This paper assists TI customers in determining the suitable power rating to be used in the advertisement of their products. TI supports customers internationally and understands that each region of the world requires different marketing strategies. While the power rating for the US market is dictated by the FTC, other countries may not be restricted to such requirements. In those cases, TI customers are open to choose the acceptable power rating for advertisement. As mentioned in the introduction, PMPO generally is not well-defined and accepted as an audio performance measurement. It is used mostly for advertisements.
The report was written in 2005. The FTC has not enforced power rating standards in the U.S. for more than 10 years...so that restriction seems quaint now.