The Opal Monitor bookshelf speakers have a two-way design based on the PSC 18.8 CS/M low-frequency driver. The low-frequency driver has been adapted to work in a smaller enclosure by changing the sensitivity of the suspensions. In the middle frequencies, the paper membrane provides an accurate warmer sound. A 25 mm tweeter with a silk dome is installed in the upper part of the range, which, due to its compact size, allowed the acoustic components to be positioned closer to each other.