I was asked to propose a solution to reduce echos in a large event hall measuring 70 feet long by 60 feet wide with ceiling height 14 feet( I have never done anything of this sort before). The room will be used for seminars & presentations for 100-200 people seated or standing. The flooring is made of vitrified tiles/ceramic tiles and the 4 walls are made of some kind of highly reflective paint. The ceiling is PoP with 12 feet long concealed ducts for AC .The echo is uncontrollable.
They are running on a very tight budget, so covering the entire floor with carpeting seems very expensive, so is acoustic panels.The ceiling is also off limits due to AC vents & lighting.
For a start i am proposing that tall indoor potted plants be placed in all the 4 corners. Then cover the first 1/3rd of the walls(toward the front ,near the stage area) from top to bottom with thick velvet curtains, and see if the echo reduces. If it doesn't do much, then repeat towards the back 1/3rd. Is there any other approach to handle this?
Also I have a choice of proposing either 15-20 in ceiling speakers(bose or QSC) covering the entire area for speech,light music &video / OR 4 point speakers(like bose S1 pro in a single loop) in the 4 corners mounted on 6-8 feet high poles. Which of the 2 solutions will be better for echo reduction? Ill be using a 3-4 wireless MIC setup without any DSP for feedback cancellation. Will it be an issue? or do i have to compulsorily use a DSP?