I hope you are tracking the responses of the members regarding your posting. The reason you mentioned for this step by the management is "due to a downfall in business."
What does this have to do with any change of designation in the first place? Revision of salary—yes, but what is the company achieving by changing the designations? And why should they?
As AS Bhat mentioned, designation is more often viewed as a punishment in relation to performance than any other issue. The moment you touch the designations, you are giving scope to the employees (levels don't matter here) to think that there's something else going on and begin to look out rather than lend a helping hand to the management—unless that is the prime motive of the management.
And, as other members pointed out, take the employees into confidence on the why of the decision, even for salary cuts. Be clear on the duration as well, at least approximately, before you begin this exercise.
In such situations, if you take a "take-it-or-leave-it" stand, then don't be surprised if the employees make their own decisions based on their understanding of what is being done by the management. The very same management may then start to say "the employees ditched the company"—I have seen such situations before.
Regards, TS