The key to success of your acoustic treatment comes with understanding which product best suits your particular needs, and then how much of that product is required to produce the intended sound effects. Within the product selection phase, sound panel thickness plays a key role in ensuring you trigger the collapse in noise you are seeking.
While sound panels serve to absorb echoes in a room, panel thickness can decay your values if you select the wrong depth. It is the frequency of the noise source that will determine your panel thickness. For mid to high pitch noise, the sound waves are easier to absorb and it will deliver more frequent amplitudes, while lower pitched sounds have longer, flatter sound waves. As a result, thicker panels are needed if the sounds are low base tones.
So while choosing your product thickness, pay attention to the frequency of your noise. Do not scale back on panel thickness to save on cost, if your noise is low base. Maybe you might spend huge amount of money and still not achieve the quality you would like to have.