Hey FRYER what audio interface are you using to connect the mixer to the comptuer? U mentioned a Tascam, is that a portable recorder or an audio interface?
Even though I can see levels when recording hitting up -5dB once it hits zero it's cracked and gone forever- if you are recording from a clean digital mixer (like the DJM2000) into a digital medium (computer/hard drive) it's best to have the peak of the music not go above -14dB- so play a track, add a fitler, add an echo then check the input levels on the computer and make sure they dont' hit anything above -14dB... once recorded you can go back and fix/normalize the levels of the set. At least this way you can boost as much as you want in post- safer option to get clean live recordings.
Hope that helps