This works particularly well with smaller bass drums.1. Tune both heads to their lowest viable pitch.2. Add an extra turn or half turn to each tuner...3. ...then de-tune *alternate* tension rods by half a turn or so - so for an eight-lug drum, for example, you would de-tune 2, 4, 6 and 8.This has the effect of disrupting the drum's fundamental pitch, so you don't hear much of the 'boom' - just a good, meaty thud. Add damping of your choice to finalise.Oddly enough, it's harder to do this accurately by simply de-tuning alternate rods upwards from step 1, which is why I don't suggest it.