The leak was fixed, the box IMO is fine, what exactly do you mean not designed for the sub?
I like big low tuned boxes, and thats what i have, as i said, its .8ft^3 at 28htz ported, IMO its perfect for my tastes, it has surprising ok low end for an 8.
My receiver is rated to only handle 6 ohms, but it takes 4 ohm like a champ, hasnt gone into protect once, and doesnt heat up any more than normal.
And with the LP, i plan to buy a crossover, but i honestly dont think its needed all that much, it sounds decent the way it is, however i have found a way to solve the problem for now, the EQ has left and right channels, and the receiver has 4 front outputs, 2 left and 2 right, i have 3 speakers in total, two yamahas, and the sub. I have the EQs left channel all on flat except for all of the higher frequencies, this should lessen the highs going through the sub, correct? The sub is hooked up to the left channel and the Yamahas are hooked up through the right channel, which is EQed to the way i like them to sound. Now i know i have no stereo sound, but it works for now till i get a crossover.