We are all familiar with the square, gold-colored folded tweeters in many popular studio monitors. Klaus Heinz, who founded HEDD Audio, spent decades refining the concept into the compact AMT (air motion transformer) designs familiar to studio engineers. HEDD now produces several monitor and headphone models that utilize their advanced, handmade version of this tweeter. Most recently, HEDD debuted their main reference monitor system, the Type 40. This system is unique in several ways, and I have been lucky enough to experience this monitor in a few different studios between Nashville and Los Angeles.
A main monitor is generally defined as a high-output, full-range reference speaker designed to maintain accuracy at the high SPLs required in medium- to large-sized control rooms. Traditionally, mains are soffit-mounted into the front wall or placed several meters from the listening position. However, modern studios have become increasingly reliant on nearfield and midfield monitors, largely for two reasons. First, their cost is considerably lower than high-quality mains, and second, many project studios and small mix rooms are too small or lack adequate acoustic treatment for far-field main systems, which take up a lot of space, require a minimum listening distance of two to three meters, and place greater demands on room acoustics.