I did a little more investigation into the Sleishman drum system and am questioning whether or not, that maybe your problem now. Because you can only the tune the drums one way. Both the batter and the resonant head must have the same tension from the rods. The drum heads tuned identical have a nice sound to them, it is constructive interference where the frequencies of the top and bottom are identical and they add to the sound of the drum because they are both vibrating the same.
In their video they show a bass drum with a port. I do not understand how that drum is tuned. It means both heads have the same tension and yet because of the port, one head will not be the same. The diaphragm movement with a port does not move the same as the diaphragm without a port. Now the constructive interference will not work, and the two heads are not the same frequency any longer.
With a normal lug drum system, you can tighten a lug in one area say 12 o'clock and find that the tension on the head 180 degrees away at 6 o'clock is also effected with the tuning. With a port, what happens? Does the lug 180 degrees away also tighten if it is through a port? I believe that with the reinforcement ring at the port, the tension is then distributed to other lugs and not the lug directly opposite the 12 o'clock lug.
Well, with the uniform tension on the batter and resonant rods, you now add another layer of complication to the tuning, you have to now tighten that lug on the batter at 12 o'clock the lug at 6 o'clock is effected as well as the lugs on resonant heads. But, you have that hole in the bass port and now the two heads are not capable of being tuned to the same pitch any longer. I believe that even if you put a muffler on the batter head across the lugs between 1 & 2 o'clock to the lugs between 4 & 5 o'clock you can not tune both heads to the same pitch any longer and this defeats the purpose of the uniform tension system.
I think with the Sleishman system, you are limited in the way you tune the bass drum.
I wonder how this effects the snare drum when you engage the snare wires on the resonant head, and what happens if you put a muffler on the batter heads. I kind of like the sound for the toms though, but question whether this is good for snares and bass drums.