Sound quality test running 1 mackie using only 1 channel but through the dbx driverack pa2. In this video all the settings are neutral so the dac/mixer read 0db output into the dbx and the mackie are set to 0db on the channel input and the master gain. The dbx has all 6 channels running full pass through with no extra settings. I'm running off the mid right channel and the dbx shows around - 15 as the output. Sound is crystal clear, very impressed but only around 100db Mark. Once I started to increase the gains on the mackie slightly there was a noticeable quality drop but for bars in which your not wanting to take down the roof, these are very impressive. Plan for me is to use the dbx system to use all my sets of speakers including subs and create a 4 way system. Comment if you would like any info.