The physical configuration of the DynaPleat line array baffle was changed between the time of the gym measurements and the listening room measurements. Those changes can be seen in the photo at the left. Hence there is an element of an 'apples and oranges' comparison between the gym measurement and the livingroom measurements shown below. Inspection of the plots themselves will show that there is reasonable ground for comparison.
In anticipation of the completion of the true ribbon driver project and due to a desire to explore the integration potential of multiple line sources and line arrays, the RD75 planar-magnetic driver was installed between the DynaPleat array and the true ribbon driver framework. The RD75 was not active during the measurements.
Obviously the total baffle width is substantially less in this
configuration than for the gym configuration. The listening room
measurements were made with the ribbon driver framework open as shown. The
baffle width, excepting the open section of the ribbon framework and it's
outer edge, is approximately 17" compared with the 27" (at the base) for
the gym configuration.
This configuration had NO acoustic foam over the rear of the array! What is surprising in the listening room measurments below is the actual low frequency response obtained, given the theoretical prediction of reduced low frequency response with a narrower baffle.
At the left is a photograph of the livingroom setup for the study. The POV
of the photo is from a standing position over the 'prime focus' seat in the
middle of a couch.
The distance between the front wall and that listening position is 11.5 feet. There is an open doorway immediately adjacent to the wall heater to the left of the left speaker. The bay window on the right is about 2' deep and 10' long.
The room itself is L-shaped, the main rectangle being 12' x 17'. The speaker pair is located at the end of the 17' dimension. The 10' square room section that creates the 'L' shape is at the opposite end of the room; and, is to the left of the camera position.
As commentary on this setup - obviously I can do what I damn well please
in regards WAF/SAF, since I don't have one at this time. It is my firm
opinion that there is absolutely no accounting for aesthetic taste in this
life!
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Acoustic Line Source Research - Table of Contents.
