We are now happy to introduce two new upgrades of the E100; The E100 HD and E100 HD+ (see separate brochure). The E100 HD looks exactly the same as the E100, from the outside, which is deliberate to make it an easy upgrade in previous designs. The E100 HD matches the standard E100 parameters close enough to just replace the driver in your current design. The main difference is in the high frequency, starting from 3Khz and up. As shown in the impedance curve comparison below, the HighFrequency impedance has been vastly improved, giving the E100 HD a very open, 3 dimensional, dynamic and detailed HF response. The E100HD is an outstanding performer in a single driver system and due to the simplicity, not having to use complex filters, it’s easy to build your own High End speaker system system in many different applications. For those of you still wanting to cross over to a tweeter at HF, the HD is probably the preferred driver over HD+ NEW: All new E100 drivers will now come with individual factory parameters!