Ok, here's the deal. I have Ocheltree's DVD. He never REALLY reveals Bonhams "secret". Instead, he says thinks like; "he tuned the bottom head WAY up", and "the bottom head would be tuned the way you would hear a snare drum being tuned". Not very technical. However with those clues, and some experimentation, I have come very close.
First, for all wood drums, you gotta go coated Emperors over coated Ambassadors. Tune the top head to just a little up from where the drum makes a nice clear resonant tone, but not enough to start choking it. Then tune the bottom head a perfect fourth higher than the top head. Do not use any muffling or dampening. The tuning takes care of the dampening. The snare tuning is high and tight, the bottom head higher but not a fourth, just until it sounds right. Snares somewhat loose, so you can hear the snares even with the lightest tap. But for the bass, I prefer Aquarian Superkick 1s. This tuning is neither original or secret, but has been used by jazz drummers for decades. Bonham was very jazz influenced, and he liked that sound. Combine that with large drums, his unique feel, and boom, classic rock god. Oh, I have a drum dial too. Sell it. They are worthless, and will drive you mad.
I must warn you that they will sound weird to you at first from behind the kit because you will hear a lot of the bottom head, and it will sound high and choked, but out in the room (where his room mikes were) they sound open and beautiful.