Sidney George Brown (1873-1948), the company founder, was an active inventor of electromechanical devices, including the Microphone Amplifier which permitted loudspeaker operation from a crystal set without the use of valves. The Brown range of horns used a moving iron, and tuned magnetic reed arrangement, in contrast to the common diaphragm electromagnetic driver in other loudspeakers. The sensitivity of the reed and the thinness of the aluminium cone were advertised as offering greater volume than other designs, but the complexity made them more expensive.