The Black Diamonds are Jewels, Home Theater Magazine. Pinnacle"s BD 500 is a pair of 5.25-Inch 2-Way Bookshelf Speakers. Pinnacle’s flagship Black Diamond (BD) series stands apart with astounding performance for music or movies, stunning cabinetry, and Pinnacle’s unprecedented value and warranty. The meticulously engineered designs employ premium quality specialized drive elements, including a highly refined silk dome tweeter for efficient reproduction of the most sensitive nuances of the program and a striking, bullet-like die-cast phase plug to improve the crossover function. The Black Diamond Series models are backed by Pinnacle"s unprecedented 10-year warranty. Designed and assembled in the USA. Family Owned and Operated. For over 30 years, Pinnacle Speakers has been synonymous with superior performance and value and is relied upon by thousands of professional custom home installers as their speaker of choice. Pinnacle products have been installed in millions of households and now their tradition of excellence is available directly to you. All Pinnacle speakers are designed in their state-of-the-art research facility in Massachusetts and most Pinnacle products are assembled at their factory in New York. Decades of Rave Reviews. Throughout the years Pinnacle speakers have been consistently recognized by the critical industry press for innovative designs, superior performance, build quality and great consumer value regardless of price point.