Sound Lock™ Door Bottom Seal

The Sound Lock Door Bottom Seal is an automatic drop-down seal that closes the gap under a solid core door. It drops in a teeter-totter motion, touching the floor at the hinge side first, then self-levels so it seals evenly on a slightly uneven floor. On its own it adds up to 5 STC points, with a maximum of STC 43. Most people pair it with jamb seals in the full Sound Lock Adjustable Door Seal Kit or with gasket tape in the Sound Lock Gasket Tape Door Seal Kit, since a fully sealed door gives the biggest improvement.

Measure your door width and order a seal that covers it, then trim it during install. The seal can never be made longer, so ordering short means starting over. All trimming is done from the end without the actuator screw. Bottom seals from 18" to 24" are custom ordered to the exact width, cannot be trimmed and have a slightly longer lead time. Call us at 1-800-679-8511 to order one.

The Sound Lock Door Bottom Seal starts at $149.99 for the 30" to 36" sizes. The 38" to 42" sizes are $159.99, and the 44" to 48" sizes are $169.99. Dark Bronze, Gold and Industrial are also available. Reach out for pricing.

Yes, the Sound Lock Door Bottom Seal is a soundproofing upgrade over a standard door sweep. It drops automatically as the door closes and self-levels, so it seals tightly even when the floor is slightly uneven.

Ideally 3/8" of gap under the door, and never more than 1/2". The mounting holes sit about 2" above the bottom of the drop seal. If your gap is greater than 1/2", you will need to attach a solid wood extension or shim to the bottom face of the door panel to bridge the gap.

To install the Sound Lock Door Bottom Seal, first slide the rubber gasket out the actuator screw side. Cut the aluminum channel only on the end without the actuator screw. Then, slide the rubber gasket back to the center of the aluminum channel and trim the rubber with scissors so it stays slightly longer than the channel (about 1/8" on each side). Rest the seal on 3/8" thick spacers with the actuator screw toward the hinge side. Screw it in starting at the center hole. Then, with the door open, back out the actuator screw a half-turn at a time until the seal just blocks light under the door.

Read the full Sound Lock Door Seal install guide before you start. Call us at 1-800-679-8511 if you have questions.

The most common cause is a seal mounted more than 3/8" above the floor. Check with a straightedge and lower it if needed. If your gap is greater than 1/2", you will need to attach a solid wood extension or shim to the bottom face of the door panel to bridge the gap. Then, install the bottom seal so the drop is about 3/8". You should also confirm that the actuator screw is on the hinge side, and that you adjusted it in quarter-turns. If the seal still will not drop and the metal is not binding against the opposite jamb, call us at 1-800-679-8511.

You only need a threshold if the floor under the door is not flat and smooth, such as carpet. A threshold adds no performance over a hard, flat floor. It is there as a hard transition.

Doors wider than 48" use a custom-made bottom seal instead of the Sound Lock Door Bottom Seal. We can make one up to 96" wide by quote request. It has a longer lead time. Request a quote or call us at 1-800-679-8511.

You can screw the bottom seal through a kickplate. However, we recommend moving the kickplate up so it sits directly above the bottom seal.

The Sound Lock Door Bottom Seal comes in Silver (clear anodized) as standard. Dark Bronze and Gold are also available and take about 1 extra week to ship. Industrial has a thicker casing, 7/8" instead of 17/32", and both casings seal equally well once installed. Reach out for pricing.