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M - Investigation of energy storage - Part 2The following graphs show linear distortion data for two 8" drivers, measured un-baffled at about 1" from the dust cap. I use the time domain information in addition to non-linear distortion test results to decide on the suitability of a given driver for the intended application. In this case I was looking for a driver to cover approximately a 100Hz to 2 kHz range in an open baffle. I use driver A in the PHOENIX and driver B in the ORION with a 1400 Hz, LR4 crossover to the tweeter. The steady-state frequency response from these close-up measurements can serve as pointer for where to probe with the burst test. Before mounting the driver on the prototype speaker baffle I want to know what is inherent in the driver and what I can expect from it ultimately. The steady-state frequency response is later measured at a distance that includes all baffle effects, on-axis and off-axis. From that I determine any necessary baffle shape changes. The driver is then electronically equalized for flat response, before applying the crossover filtering. This is an example of two very successful driver designs in terms of low linear and non-linear distortion. They are far from perfect, but well behaved when used within their optimum operating range.
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