ESB Audio 4.UMA 2-Way Mid-High UnitESBs goal for its new 4000 Series was to push the limits of cost vs. performance. We know of no other car speakers currently on the market at these price points that make use of the same advanced materials or surpasses their remarkable performance. The particularly expensive design of the 3 75 mm midrange driver and its high grade, high energy neodymium magnet guarantees a level of efficiency that supports high sound pressure levels even when paired