Much good advice here, so I'll just try to add a little.
Some subs are designed for a ported enclosure, and some are designed to work best in a sealed enclosure. You have to find the manufacturers information specs on your exact woofers and build the boxes exactly to spec. I can't stress how important it is to have the right size enclosure and be ported correctly if it needs to be ported. Either way, sealed or ported you will get tight bass if you've built the box correctly and drive them with a good clean signal and proper power. Sealed is generally tighter, but ported will be great also if you do it to spec.
What kind of amplifier are you running and what kind of head unit or signal source? I've seen guys with amps that have "bass gain" that the owner will turn way up, then crank up the gain too high and both overdrive the amp and distort the signal worse by using the stupid bass gain.
Reduce crossover to 80-100hz
build boxes exactly to spec, including port tube diameter, depth ect. Making a perfect shape box with a port tube that isn't right will result in shit bass. It all needs to be to spec.
If you have a bass gain on the amp, set it to zero - set bass gain on the headunit to zero.
You could also have the drivers facing the wrong way. They called it "transfer function" when I was into this stuff, not sure if it's the right term, but it's basically positioning of the speakers in the car to get the best performance from the shape of the vehicle. Sometimes facing backwards away from you, pointed at the rear of the truck will improve performance drastically. You just have to play around a bit and adjust, listen, adjust listen.