In our quest to eliminate subjective or problematic rules, the dBDRA Officiating Committee has made the following change regarding the definition of a "Wall".
Wall - The dBDRA defines a speaker wall as any subwoofer enclosure and / or baffle board that meets one or more of the following conditions...
Enclosures that are greater than 30 inches (76.2 cm) in height.
Any installation which results in a vertical clearance between the top of the enclosure and the headliner of 13 inches (33 cm) or less. (This clearance requirment also applies to any equipment which may be mounted to the enclosure.)
Wall Test - The judge shall use a mic jig (or other appropriate measuring device) to verfiy a vertical clearance of 13 inches (33 cm) exists everywhere between the top of the enclosure (and any equipment attached to the enclosure) and the headliner. The judge will then verify (if necessary) the height of the enclosure to insure that it is less than 30 inches (76.2 cm) in height.