Amplifiers are one thing, but the priorities for THX speakers, if there really is much of a standard anymore, has never been the same as my priorities for speakers. THX puts a high priority on efficiency... over things like imaging and unmeasurable aspects of sound quality that are a priority to me. I can get a more powerful amplifier to overcome the lower efficiency, but the only way to get the sound quality I want from speakers, is with speakers that provide it.