Pannyman

I bought a JL 10w7 and a 500/1 and at first I loved the bass but it seemed that overtime it got less and less loud. I doubt that its the amp at this point my guess is the sub or that I need to buy a cap or two. I really don't know that much about systems. If someone could please suggest to me another brand possibly or if a 13.5w7 is gonna be enough......I wanna feel it.

Also if I do get another system my set-up will be for sale.

XBFred

before you buy equipment need to do some trouble shooting.... you don't need a cap, but make sure you have enough power going to the amp. Make sure you cables are big enough. Check your box size etc.


If your equipment is fine, it might be as simple as you are used to the output. If that's the case, keep the amp and pick up a couple nice 12's or maybe a new ported box for you sub might do it... make sure it is built to spec. Ported boxes are harder to build and need to be exact to really sound good

UV7

The JLW7 series are power-hungry woofers. Pairing them up with a JL Slash series amplifier, which has an unregulated power supply, is going to put a significant strain on the charging system of your xB, which is already weak from the factory. Since the slash series amps are unregulated, they will continue to pull as much current as is necessary to maintain their output. This is one of the significant differences between JL's Slash series and A series amplifiers, which have a regulated power supply that limits the amount of current they can draw from the charging system.
It is possible that you are pulling beyond what the charging system is capable of delivering, which would cause a decrease in output, as well as many other issues that could be detrimental to the health of your vehicle.
As Fred stated before, you need to ensure you are giving the sub/amp setup enough current to circulate throughout the setup. This means thick gauge, low-resistance wire for both power and ground. As well as the appropriate wire, you are probably going to need a larger capacity battery in order to provide sufficient current for the sub/amp setup. The stock charging system isn't strong enough to provide this setup with the necessary current without hindering the performance of other current requirements throughout the car.
You have probably already noticed your lights dimming with every good hit of the sub. This is a symptom of a weak charging system struggling to provide enough current for every requirement. As the bass hits, the amp draws more current from the charging system, thereby causing a decrease in the provided current to the rest of the electrical system, which causes the lights to dim due to a lack of necessary electricity. This can become a serious issue if too much current is being drawn. It could damage other electrical components.
Before you go changing your sub setup, you really need to evaluate the capacity of your charging system. After all, if it is too weak for a JL10W7 and a 500/1, it is probably going to be too weak to support anything stronger.