Help with Circuit Board

The effect light below is supposed to sequence the lights on and off, one at a time, in response to music (sound). Well it does that, but not until the input is around 95 - 100 DBs. I'm trying to figure out what to replace so that it responds to sounds at lower DB levels. The left knob on the rear is for sound adjustment (worthless at this point), the right knob is the chase (sequence)speed. The sound is set to max and the lights still doesn't respond until you really crank the music up. CN2 is where the sound and chase controls connect. It's wired, left to right as follows 1 - red from chase knob 2 - yellow from chase knob 3 - red from sound knob 4 - yellow from sound knob 5 - blue from sound knob The pin block in front of CN2 is power and the other block goes to LEDs on the rear of the unit. I'm trying to figure out what I can replace to make this more sensitive to sound input. The mic isn't the issue, I've tried several and even directly wired headphone input into it and still had to crank it up before it would respond. No comments on my soldering butcher job on the back. The red wire is the positive to the mic (which should be in the burned out hole to the left, but it works there - no better, but no worse) Any thoughts at all on what I could play with to make this thing respond to sound a lower levels would be greatly appreciated.