@Novachord On each track, use an EQ plugin that shows the audio spectrum. See what parts of the sonic spectrum it's taking and shape it with the EQ. Sometimes boost the frequences of that track but often use the EQ to cut offending frequences and make it sit in the mix.

After doing that to each of the tracks, THEN use a sidechain compressor to duck them out.

I think it's a two part process in that order.