The goal of the loudspeaker designer is to extract the optimum performance from each driver while blending all drivers to achieve a flat frequency response and a stable, linear phase and impedance of the system. Frequency response and impedance is greatly affected by the environment of the drivers. The internal volume of the cabinet behind the woofers, the shape and dimensions of a tuned port (if any), the amount of insulation, the mounting of the drivers, the shape and dimensions of the cabinet baffle, the shape and dimensions of the drivers themselves, the location and orientation of the drivers on the baffle, the thickness and resonant properties of the cabinet, etc., are all environmental conditions affecting overall performance. The list goes on ...       There are too many variables affecting the overall response of the system to mathematically predict end results from theoretical data. There is only one way to account for ALL variables and that is to measure the frequency response (SPL) and impedance of each driver section when they are installed in their final environment, then blend the sections together. The "final environment" should even include appropriate placement of the speaker in the intended listening room, but we can't quite get that close to each customer on a production basis. So we settle for anechoic measurements. All D+S speakers are built with the following process: Electromechanical woofer parameters are measured by the LMS computer hardware system. The data is imported into the LEAP computer software system to compute the optimal cabinet volume and port dimensions for deepest and smoothest bass alignment. The cabinet is built to completion with insulation and all drivers and ports installed. Leads for each driver section (woofer, midrange, tweeter) are hung out the port for individual measurements. Full range anechoic measurements of impedance/phase are made by LMS for each driver section. Full range anechoic measurements of on-axis SPL/phase are made by LMS for each driver section. All impedance and SPL measurement data is imported into LEAP for analysis. Conjugate networks are optimized to flatten impedance and phase of each driver section. Crossover (with conjugate circuits) is optimized to flatten SPL response to within +/- 2db. Crossover is built using highest quality components. Speaker is tested with crossover outside enclosure to verify correctness. Crossover is then installed and the speaker is fully tested and broken in. This is our proprietary EDC™ process for building crossovers and we do it for every unit made! This process ensures consistent ruler flat response with linear phase and precise imaging. No "mass produced" store bought speaker can ever come close.