I have two kicker solo baric l5 subs and a kicker kx 800.2 amp powered and grounded by an 8 gauge wire and when i first hooked them up they sounded great and at night my headlights didnt even dim at all. After about 2 weeks of having them hooked up i noticed that the subs began to bottom out when i turned them up real loud and at night my headlights began to dim badly (my truck is a 97' and has the original battery in it). I was thinkin that I probably just needed a new battery but im not for sure, it also makes me think my amp could be losing power. Any help would be appreciated.

 

First off, get a bigger ground. AT LEAST 4 gauge. Personally Id probably run 2 gauge(overkill, but I like overkill ).
How big of wire do you have running from the battery to your amp?

Are you sure your subs are bottoming out? Do you have them in a sealed or ported box? If its ported what is it tuned to? What kind of music are you listening to also?
The only way I can see that set up bottoming out is if you have them in a ported box tuned high, and you are playing music with some low notes.

Also, did you use a DMM to set your gains? If not, aproximatley how high is your gain ****?

Finally, do you know if your truck has the HO alternator, or standard one? Any other big electrical devices youve added (lights, etc).

 

I have 8 gauge running from my battery to my amp, i bought a 4 gauge wire but the wire is to big to stay tightened in the amp. My boxes are sealed but i might add they are pretty small enclosures for L5 10" subs. But like i said before the subs sounded great at first and then one day they just got to where they didnt sound good at all and songs that sounded really good before were bottoming out (they are mostly rap songs). I'm really not sure about the alternator whether its HO or just normal. It's really a weird situation, everyone ive talked to has said that to them it sounds like i just need a new better battery. The battery in it now has no trouble with starting the truck but I think where its so old its having problems constantly pushing 800 watts.

 

....and the only other electrical thing i have added is 2 washer lights on the hood that run off the battery and are controlled by a switch, nothing major

 

Stop listening to Rap and your problems will be solved

 

If your subs are actually being overdriven or "bottoming out", as you say, the only thing that would cause that is something being used beyond its capabilities.

 

Have you made sure all your connections are good? If it's the original battery it wouldn't hurt to put in a new one anyway. That "might" solve your problem. There's also the remote possability that the alternator is getting weak and starting to draw more off the battery to power everything. A good auto shop should be able to test the alternator and battery to see if one is having problems. Personally I'd just go ahead and change the battery out first. Upgrading to larger wire never hurts either.

I do agree that it sounds like you're not getting enough power to the amp. That amp and sub combo shouldn't be having problems unless something is failing somewhere.

 

sounds more like sub failure. Pull the subs out and check the spider and surround see if it is still firm to move the sub back and forth. 2 things can happen 1 the spider or suround are weakened allowing the sub to move too much and the impeadence drops drastically causing the amp to see a real small impeadance load, or 1 or both of the voice coils is/are damaged to the point the impeadance is lower than it should be. Easy indication would be smell inside if its a sealed box. The dimming lights are probabaly a byproduct of the amp seeing a lower than normal imp load and drawing a lot of power to drive it. If either of these are the problem reset your gains again or the same thing will happen again.

 

clipping an amp can sound very much like a sub bottoming out too. either way you gonna want to grab the dmm and ohm out the VC's and see if they are still in spec and then set the gain on the amp accordingly