I've posted Williston Audio before, he showed up the micro sub-woofers that would be cool in a new mini- boombox. In this video he's trying to put in bluetooth in his Emerson CTR949, a unit that he had as a kid. It's a little more difficult than he thought with the tightly mounted circuit boards. More of his videos are on car stereos but even some of those fun. He must be reading the forum! Here he converts a beautiful vintage Alpine Car Stereo for home use.
