Assigning a natural frequency limits to composite beams (RAM steel)

Question

Hello, 
 I have completed a model of an entire floor plate and in RAM Steel. I wish to change the design frequency for the composite beams to 4 Hz in some areas and 6 Hz in others. 
 I cannot find any way of achieving this. I have found a way of changing the natural frequency via the "RAM defaults utility-RAM Steel- Effective Length/Frequency BS5950" but this only changes new models and not existing ones. There must be a way of changing the natural frequency requirements within existing models? 
 Any help is very much appreciated!

Seth Guthrie · Answer

Within the Ram Steel beam module, you'll find the same settings under Criteria - Design Defaults, but only when the design code is BS 5950. We recommend the use of FloorVibe, which can be launched from within the program - Vibration menu, for evaluation of floor vibration.

Seth Guthrie · Answer

When we have items in the criteria menu they always apply to the whole model. Only options under the Assign menu can be delegated to particular members. 
 See this about FloorVibe: It sounds like you need to install it, or get up to the latest RAM SS version which includes it.