Posted by Rob G. (A) on November 19, 2004 at 07:07:37

(GOAL: Recreate, as close as possible, the full SIZE and SCALE of a large orchestra, using full-range DIY linesource dipole speakers.)

I have developed plans to build a modest custom home with a large, by domestic standards, "loft style" room that will serve as living/listening room, study, dining room and kitchen. As the plans stand, this rectangular space is 27' wide x 32' long with a flat 14' ceiling. Built on a concrete slab, the walls will be insulated concrete forms, which are 9" of re-bar reinforced concrete poured into permanent forms of 1" thick rigid insulation, covered by drywall. Various investigations suggests I will have room resonances at:

--40.3hz floor-to-ceiling
--20.9hz side-to-side
--17.6hz lengthwise

My speakers will pretty much run out of steam at 25hz after substantial bass boost to address dipolar cancellation. At this point, I am not planning subs, but the main room is designed in such a way that a multi-driver infinite baffle sub can be added later.

The linesource propogation will limit (not eliminate) the scale of the floor and ceiling reflections, but I assume that I will still be exciting this resonance with 2nd, 3rd and higher order reflections. Correct?

So, at first glance, it would appear that any major room resonances would be below the 41hz bottom range of orchestral instruments. Save for echoes (addressed in part via many diffusive elements in the wall shelving, furnishings, etc.), have I crossed some sort of "good room" threshold here, due simply to the size of the space?

Rob Gold