The Active Filter High Pass Crossover Response in the
The Listening Room Measurements.

Shown below is a plot of the electrical response of the active filter used in the Listening Room measurements. It has a far from perfect 2nd order Butterworth response. The attentuation slope is too shallow, which means the crossover protection requirements for the RD75 driver are not being fully met. To date (February 1999) there has been no indication of any problem resulting from the use of this device.

The frequency response plots in the Listening Room measurements all incorporate the low frequency attenuation of this filter.

The active filter is an Altec-Lansing brand autosound device acquired at great discount, and modified for use with a linear power supply. It was discovered after the fact why the units were so cheap, their switching power supplies were not operational!

The Carver 60" & RD75 Comparison.
The Listening Room Measurements - Table of Contents.
The RD75 Dipole Baffle Study - Table of Contents
Acoustic Line Source Research - Table of Contents.