Every time I bought something for the home theater, my wife questioned it at first but, then got used to it, then required it. Pro-Logic surround sound? After hearing the horses clip-clop behind her in "Dr. Quinn, Medicine Woman", she was hooked. Subwoofer? After hearing the T. Rex shake the glass of water in "Jurassic Park", she understood. Laserdisc player? "Terminator 2". DVD player? "The Fifth Element." Dolby Digital/DTS A/V receiver? "Fantasia 2000". TiVo? Never missing an episode of "Oprah". HDTV? Anything on Discovery: HD. You just have to find out what about your proposed purchase will benefit her as well as you.
Finally, when I decided to upgrade my speakers all around, she not only blessed it, she insisted on it. And when the Onix Rockets arrived, she marveled at the finish on them, loves them as furniture and marvels at the sound.
