Essential Compressor Controls
  The effectiveness of a compressor of any kind is ultimately determined by the signal being presented to the compressor. For this reason, there is no one overall setting that will work properly as this will vary from scenario to  scenario. However, a basic breakdown of the essential controls will help in the understanding of the compressor unit itself First, will be the THRESHOLD knob, which will determine the amount of signal in dB that is presented to the compressor. Start with the THRESHOLD knob turned all the way over to the right. Now, with a strong signal source being sent through the compressor, slowly turn the THRESHOLD knob back to the left. When this process is started, the signal source will more than likely be very low in volume, or not even heard at all. However, as the THRESHOLD knob is turned back to the left, the signal source will start to be heard more strongly. Get the THRESHOLD knob set to the appropriate level for the scenario.  The RATIO knob can then be used to determine how much compression will be applied to the signal. The more the RATIO knob is turned to the right, the more the compression is applied to the signal. Once this is set, then the ATTACK and RELEASE knobs can be set appropriately.The ATTACK will determine how quickly the compressor will grab a hold of the signal once it has exceeded the threshold level. The more the ATTACK knob is turned to the right, the more slowly the compressor will kick in and grab the signal. For the RELEASE knob, this will determine how quickly the signal will be released from the compressor after the level of the signal has dropped below the threshold level setting. The more the RELEASE knob is turned to the right, the more slowly the signal will be released from the compressor.