STUDIO ACOUSTIC CONSTRUCTION:
The studios will be designed to have a reverberation time of 0.2 of a second and an internal noise level of no greater than NR25 based on octave band analysis, which complies with international broadcast recommendations.
The studio walls will be a box within a box structure. The studio will be sectioned off from the remainder of the building with a partition that is constructed to fit tightly up to the existing soffit. The studios themselves will be constructed as individual boxes from modified "Camden" partitions that are contained within the outer wall and each of the studios will have its own ceiling joists and isolation ceiling.
The outer barrier wall will be constructed from 75mm x 47mm softwood studs on 400mm centres. The studwork will be clad each side with a 12mm layer of fibreboard and two layers of Gypsum 15mm Soundbloc Plasterboard. All plasterboard joists are to be butt-jointed on the timber members, staggered, taped and filled. The exposed side of the outer wall is skimmed. This construction exceeds 30 minutes fire rating.
The studio walls will be constructed from similar softwood studs but modified to permit building from one side with 12mm fibreboard and two layers 15mm Soundbloc plasterboard each side. All plasterboard joists are to be butt-jointed on the timber members, staggered, taped and filled.
The fibreboard, which serves to damp the resonance in the plasterboard as well as partially isolating the plasterboard from the timber frame, contributes a significant portion of the mass and therefore increases the sound insulating properties of the partition.
All studio frames will be filled with Rockwool insulation between the facing sheets.
The cavity between the partitions will be blocked at the end of each wall with dense Rockwool to act as a cavity barrier and trimmed with hardwood edging.
All studio and outer walls will have their sole and head plates mounted resiliently from the existing structure using a quality hair felt material and non-setting mastic.
The inside of the studio walls will additionally be clad with softwood framing, Rockwool between the studs and a hardboard covering that is perforated depending on position on the walls to approximately 0.05% or 5% of area to control the acoustics of the room. This hardboard will then be covered with a plastic sheet, dustsheet and a tight weave fabric that is fire treated to class 1 speed of flame.
The ceilings will be constructed from 200mm x 47mm joists spaced at 400mm centres. The underside will be clad with a layer of 12mm fibreboard and two layers of 15mm Soundbloc Plasterboard. The cavity between the joists will be filled with 100mm Rockwool insulation. A suspended acoustic ceiling will be fitted in the studios and sound lobby underneath the plasterboard ceiling.