Listening Distance Comparisons - 1.00m Height

The same RD75 driver was used in each of the differently shaped baffles used in these comparisons. The measurement conditions were similar, and the testing was performed in the large gymnasium. The responses shown are 1/12 octave smoothed, and are the result of the merging of a 61KHz sampling rate full range measurement and a 1.9KHz sampling rate high-resolution low frequency measurement at approximately 625Hz. The required passive notch filter was used in all measurements; but, no high pass filter was used. A high pass filter (125-150Hz)is required in normal use to protect the driver; and, could be expected to significantly alter the very low frequency response of the driver.

Please note, that the phenomena of 'moving dips' significantly alters the frequency responses seen in these comparisons.

The baffles compared are:
1S6T - One of the original series of 'one-sided' baffles based upon the composite baffle construction. A trapezoid, 18" base & 12" top. An 'Equal Area' baffle.
1S9T - One of the original series of 'one-sided' baffles based upon the composite baffle construction. A trapezoid, 21" base & 12" top.
1STR - A new series 'one-sided' baffle attempting as much a triangular shape as possible. A trapezoid, 23" base & 5" top. An 'Equal Area' baffle.

Comparisons at 3m Distance and 1.00m Height. 1/12 Octave smoothing.

Comparisons at 4m Distance and 1.00m Height. 1/12 Octave smoothing.

Comparisons at 5m Distance and 1.00m Height. 1/12 Octave smoothing.

Comparisons at 6m Distance and 1.00m Height. 1/12 Octave smoothing.

Listening Distance Comparisons - 1.25m Height.
RD75 Database - Table of Contents
The RD75 Dipole Baffle Study - Table of Contents
Acoustic Line Source Research - Table of Contents.