Plot below shows the frequency/magnitude plot at 2 m, 1 m and 1/2 meter from the BG RD75. It is nice to see that above 2K magnitude increases 3dB with halving of the distance in close proximity of the driver. As seen before, at these close-up ranges, there is a huge bump below 1kHz. The peak-and-dip magnitude changes can probably all be explained by reinforcements/cancellations between direct and indirect sound.