Passage: The Wii has received generally positive reviews. The system was well received after its exhibition at E3 2006. At the event, Nintendo's console won the Game Critics Awards for Best of Show and Best Hardware. In the December 2006 issue of Popular Science, the console was named a Grand Award Winner in home entertainment. Spike TV's Video Games Award cited the Wii's breakthrough technology. GameSpot chose the console as having the best hardware in its "Best and Worst 2006" awards. The system was also chosen as one of PC World magazine's 20 Most Innovative Products of the Year. The console received a Golden Joystick for Innovation of the Year 2007 at the Golden Joystick Awards. In the category of Engineering & Technology for Creation and Implementation of Video Games and Platforms, Nintendo was awarded an Emmy Award for Game Controller Innovation by the National Academy of Television Arts and Sciences. In 2009, IGN named the Wii the 10th greatest console of all time (out of 25).The Wii's success caught third-party developers by surprise, leading to apologies for the quality of their early games. In an interview with German news magazine Der Spiegel, Ubisoft's Yves Guillemot and Alain Corre admitted that they made a mistake in rushing out their launch titles, promising to take future projects more seriously. Take-Two Interactive, which released few games for the Nintendo GameCube, changed its stance towards Nintendo by placing a higher priority on the Wii.At the same time, criticism of the Wii Remote and Wii hardware specifications had surfaced. Former GameSpot editor and Giantbomb.com founder Jeff Gerstmann stated that the controller's speaker produces low-quality sound, while Factor 5 President Julian Eggebrecht criticized the hardware audio as substandard for a console of its generation. UK-based developer Free Radical Design stated that the Wii hardware lacks the power necessary to run the software it scheduled for release on other seventh-generation consoles. Online connectivity of the Wii was also...

Question: For what did Gerstmann criticize the controller?
low-quality sound