To provide a shaker and a method of testing suitable for various applications, including those presenting adverse test environments.

The shaker has a permanent magnet assembly mounted in a sealed housing for vibration along a shaker axis. The permanent magnet is double ended, and includes at least one shorting ring to hold down the inductance of driving coils at higher frequencies. Fluid cooling (or heating) of both the shaker housing and the permanent magnet assembly allows placement of the shaker inside a temperature test chamber. The shaker may be coupled directly to an article to be tested, or coupled singularly or in a plurality to a test table to which the article to be tested is coupled. Various embodiments and methods of testing are disclosed.