Electroacoustic network

DETAILED DESCRIPTION I claim: 1.
A co-axial pair of high and low frequency electroacoustic drivers wherein the high frequency driver is mounted in front of the low frequency driver, a cross-over filter network connected in the electrical signal path to both drivers, and a delay network connected in the electrical signal path to the high frequency driver, the improvement comprising components of the filter and delay network being selected and adjusted for a substantially flat amplitude versus frequency response within the pass bands and through the cross-over frequency of the drivers and a substantially flat phase versus frequency response both within and beyond the pass bands of the low frequency filter driver network and the high frequency filter, delay and driver network, and, means to substantially prevent direct sound radiation between the high frequency driver and the low frequency driver without inhibiting direct sound radiation from the low frequency driver to the environment comprising a sound absorbent material surrounding the side and back of the high frequency driver and an annular open space between the low frequency driver and the sound absorbent material.
2.
The method of adjusting the elements of an electroacoustic network including a delay network comprising the steps of: applying an electrical impulse signal to the signal path of the electroacoustic network and to a timer to trigger a delayed second identical impulse signal, applying the second impulse signal to one channel of a spectrum analyzer, sensing the acoustic output of the electroacoustic network and applying the sensed output signal electrically to another channel of the spectrum analyzer, generating a frequency by frequency comparison of the amplitudes of the two signals input to the channels of the spectrum analyzer and a frequency by frequency comparison of the relative phase angles of the two signals input to the channels of the spectrum analyzer, generating a Fourier analysis of the frequency by frequency comparisons of the signals in the spectrum analyzer, displaying and viewing the acoustic phase and amplitude versus frequency response curves resulting from the analysis, and in response thereto, adjusting the electroacoustic network to thereby flatten the acoustic phase and amplitude versus frequency response of the network