Frame, jamb, threshold, and seal specifications for each acoustic door
[AC] All door assemblies are Acoustic Critical. See the
Modification Policy
before substituting any frame, seal, or hardware component.
BUILDER CUSTOMIZATION GUIDE -- DOOR ASSEMBLIES
CUSTOMIZABLE -- Door leaf surface finish (veneer, laminate, paint colour), handle/lever hardware style (if maintaining required latching force), threshold cover plate finish, door signage and room labels, viewer/peephole brand.
DO NOT ALTER -- STC ratings (D1:50, D2:45, D3:45, D4:40), door core construction and fill material, frame gauge and profile, perimeter seal type and compression rating, automatic door bottom model, glass layup in observation windows, frame anchoring method, gasket compression dimensions. All door assemblies are Acoustic Critical -- no substitutions without written approval from the acoustic consultant.
A Full Door Cross-Section
B Head Detail Close-Up
Head / frame junction detail
Threshold / drop seal detail (D1 with rain deflector)
C Hardware Checklist
Component
Specification
Qty
Critical Notes
D Installation Sequence
A Full Door Cross-Section
B Head and Threshold Details
Head detail (STC 45 interior doors)
Threshold detail (STC 45 interior doors)
C Hardware Checklist
Component
Specification
Qty
Critical Notes
D Installation Sequence
A Full Door Cross-Section
B Head and Threshold Details
Same as D2 Control door. See D2 panel for head and threshold close-up drawings.
Frame: 18 ga steel, grout-filled. Threshold: automatic drop seal. D2 and D3 share identical STC-45 frame assembly; D4 uses an STC-40 assembly matched to the W7 partition.
C Hardware Checklist
Component
Specification
Qty
Critical Notes
D Installation Sequence
A Full Door Cross-Section
B Head and Threshold Details
Similar frame assembly to D2/D3. See D2 panel for head and threshold close-up drawings.
Frame: 18 ga steel, grout-filled. Threshold: automatic drop seal. D4 uses STC 40 rated leaf matched to W7 partition (STC 40).
C Hardware Checklist
Component
Specification
Qty
Critical Notes
D Installation Sequence
Side-by-Side
Door Comparison
All four acoustic doors at a glance. Specifications sourced from the project SSOT.
Attribute
Critical Requirements
Installation Warnings
Non-negotiable quality checks. Failure at any of these points compromises the acoustic envelope.
!
Light Test
No light visible around closed door perimeter. Test in darkened room with bright light source on opposite side. Any light leak = sound leak.
!
Drop Seal Contact
Drop seal must contact threshold plate full width. Use slip paper test across entire threshold. If paper slides freely at any point, adjust seal.
!
Sealant Type
Acoustic sealant (non-hardening) at all frame-to-wall joints. NOT construction adhesive, NOT silicone caulk. Only approved: Tremco Acoustical Sealant.
D1
D1 Exterior: Dual Seal Systems
Exterior door requires weather seal AND acoustic seal as two separate systems. Weather stripping protects against moisture ingress. Acoustic gasket provides sound isolation. Do not substitute one for the other.
Ongoing Performance
Seal Maintenance
Acoustic door performance degrades over time. A 1mm perimeter gap can reduce effective STC by 10–15 points. Annual inspections are essential.
Engineering Advisory
Door seal maintenance is not optional. Even correctly installed acoustic doors lose performance as gaskets compress, drop seals wear, and closers drift out of adjustment. Schedule annual inspections as part of facility maintenance.
Seal Inspections
Perimeter gaskets: Check for compression set, cracking, or gaps — replace if any light is visible around closed door
Drop seals: Verify full contact with threshold when door closes — adjust or replace mechanism if daylight visible
Threshold gaskets: Inspect for wear from foot traffic — D1 exterior threshold especially prone to degradation
Magnetic seals (D1): Verify magnetic strip alignment and pull force > 2 kg/m
Hardware Checks
Door closer: Verify latching force pulls door fully into seal contact
Hinge pins: Lubricate annually — squeaking causes staff to prop doors open
Closing speed: 3–5 seconds from 90° to latch — too fast damages seals, too slow encourages leaving open
Prop prevention: Consider magnetic hold-open devices that release on studio “LIVE” signal
Critical
Propping acoustic doors open during sessions destroys all isolation. Even 30 seconds of an open door during a recording session can render that take unusable. Consider interlocked magnetic hold-open devices connected to the studio tally/live light system.