The diaphragm membrane of the RD75 'sees' two significant differences between the front and rear structure of the driver. Of greatest significant is probably the 'horn' structure on the front of the driver. As much as for any reason, the 'horn' structure is there to stiffen the length of the driver. Without the horn structure attached, it has been reported to me, the driver will flex along it's length.
Without a doubt the horn structure also increases to some extent the the high frequency capability of the driver. The second difference is that the rear wave from the diaphragm encounters foam damping material in the rear cavity of the driver.
There's not a lot of 'excitement' in the three overlayed comparisons below. The larger 1S9T baffle was used for these measurements. It can be seen that the on-axis frequency response differences between the front and rear are stable with distance; and, not particularly significant except above 10,000Hz. Which is no doubt the region in which the front 'horn' is having some effect.
1m rear response comparison: 1S9T baffle. 1/12 Octave smoothed.
2m rear response comparison: 1S9T baffle. 1/12 Octave smoothed.
3m rear response comparison: 1S9T baffle. 1/12 Octave smoothed.
The Gymnasium Measurements - On the Edge.
The Gymnasium Measurements - Let's Get Foamed.
The RD75 Dipole Baffle Study - Table
of Contents
Acoustic Line Source Research - Table of Contents.
