Krieger Specialty Products
Krieger recommends the following closers and guidelines for gaining maximum performance from your sound control doors.
Please note that all UL rated sound control doors will require a closer to be UL certified.
Parallel Arm Closers
Mount the arm bracket to the "Z" brackets furnished by Krieger, or use a top jamb mounted closer. Never mount closer arm shoe directly to the seal cover.
Rixson Floor Closers
The arm which must mount in the bottom of the door precludes the use of a mortised door bottom. Krieger does not recommend using this hardware item on sound control doors.
Concealed Overhead Closer
Krieger cannot certify an STC rating for these closers because they mount directly into the head of the frame and prevent a continuous perimeter seal resulting in sound leaks.

Since cam lift hinge assemblies require closers that allow for 3/8" vertical movement, Krieger offers the following manufacturer and model recommendations (with non-hold open arms):

LCN: 4010, 4020, 4041, 4040
Dorma: 8600
Corbin/Russwin: DC8000
Norton: 7500/7700
Sargent: 281, 351
Yale: 400/4400
Stanley: QDC 111R

NOTE: Krieger has not received any documentation from Norton, Yale, Corbin/Russwin validating Krieger's recommendation.
Closers Not Recommended for Use with Cam Lift Hinges
Heavy Duty Rigid closer arms will not allow 3/8" vertical movement. Closers with a large Hold Open knuckles at the elbow that will not allow 3/8" vertical movement. Slide track type closers. Overhead stops.