Power issues.....Please Read
 

So I've searched this forum for my answer and decided to ask you people for help on my problem. I'm new to car audio, so please bare with me.

I have 2 punch 10", pushed with a 520w amp. These items are in a '07 Chevy Silverado. Now, I noticed when I got the truck that the interior lights would dim when I hit the window switches, sometimes the hitting the brake would cause the same issue. When this is happening, the voltage meter on the dash, flucuates between 12 & 14 volts. Seems like a power issue. So when I hooked up my system, the amp loses power when the bass hits. Also putting a voltage meter on the amp shows it drop from 14v to 12v when the bass hits and sometimes even further. This worsens as I increase the volume to the point that the amp cuts out completely. My alternator pushes 145 amps. This seems to be plenty of amperage for the size amp & subs that I have. I had the same amp with 2 12" Bostwicks in a 2001, same model truck and never had problems.

What is the problem and what is the cheapest way to fix it? I've read a few things about the big 3. Please explain the big 3? I believe its something to do with wiring 'must'.

Thanks!

You will find out plenty about the big 3 if you search for it, but in short it is upgrading the engine/alt ground, battery ground, and power feed to the battery from the altnernator with larger gauge wire. Many use anything from 4gauge (thats all I used since I only have a 75amp alt and don't run a huge system, but it definitely helped with voltage drop/dimming) down to 0. For your application in particular, I suggest 2 or 0awg wiring.

In the case of grounds it is better to add rather than replace. Current will take the path of least resistence anyways.

You could try the big 3, adding a capacitor, adding a better alternator, a low resistance battery.... There are many things. The cheapest, as mentioned above, would be to try the big 3 first.

is your amp class D ? or A/B ?

I got a 120amp alt. basically I had one 10" hooked up to an A/B type amp feeding about 400wrms into the sub and the lights would dim like crazy. Then I switched to a class D monoblock and the issue was gone for good. Even though I didn't need the big 3 I still installed it because it doesn't hurt that's for sure.

so your saying a class d draws less?

it is more efficient. I guess it means that it needs less to provide the same amount of output as AB. Therefore most likely it actually draws less current.

I didn't buy the monoblock to fix the problem though, I had my sub running off my 4ch bridged temporarily while waiting to find and purchase a class D monoblock. So this was my observation.

huh? class d`s are more efficent DRIVING subs than a AB because they provide much more power, therefore as a result depending on you sub/amp combo will have a far greater current draw that a 2 or 4channel amp. buying a mono block will not fix this problem.

Here's the thing... when I got the class D monoblock I added it to the system and hooked up new speakers all around to the 4ch. So the draw increased at least twice. But once the sub was on the mono the lights don't flicker no matter how loud I crank it.

that really dosent make sense though lol...maby the draw is so bad you just cant tell because the lights are so dim lol...

both dash and cabin lights are the same as when I had no system (nice and bright that is). I still get the dimming when I operate the window regulators but that was there before also.

Have you tried anything out yet or what? Let us know how its going.

Yes class d's are generally much more efficient than a/b class amps. Say the ab class is 60 percent efficient which is reasonable for ab possibly a little low, and the d class is 85 percent which is a pretty good d class amp. Lets take even numbers even though its not the actual values of the vehicle with a 100 percent efficient system 12volts x 100 amps would be 1200 watts rms. With a d class having 80 percent efficiency you would need 125 amps to produce 1200 watts rms, a a/b class amp with 60 percent efficiency would need 167 amps. There would be why a d-class amplifier would help to reduce the strain on a vehicles electrical system. Because d-class are more efficient less electrical energy is wasted as heat.

Well, I upgraded my power wire and ground to my amp both to 4 gauge as opposed to 8 gauge. I grounded my amp straight to the battery to see if that was the problem and that didn't help. I installed a optima yellow top battery and that kept the amp lights from dimming everytime the bass hits, but it still clips bad. The battery didn't help the interior lights of my truck from dimming though. I orderd a new amp and it will be here by the end of the week. Hopefully this is the problem because I have run out of things to try and I'm tired of funding this experiments.

I haven't tried the big three. I have a Chevy Silverado, I'm assuming all battery power and ground is already 4 gauge, looks to be anyway. The only wire that I could upgrade is the one from the alternator to the battery. It looks like 10-12 gauge. I just haven't explored on how to rig up that plug that goes into the alternator.

Any suggestions on what I've done and what could still be the problem? I'm thinking its not a power issue anymore.

The new trucks usually come with a pretty big alternator, especially if its a V8. My chevy came with 2 ga. battery to starter, but only 4 ga. alt to starter.
I thought it was strange that it was wired that way but apparently its common. While i was installing and was under the car anyway, i checked all the connections i could get to. quite a few of the nuts were fairly loose, so i tightened them up. Don't know if that makes a difference, but you'd better check. Something else thats hard to find is a bad crimp connection, you can drop a lot of voltage on a bad crimp. You can find these with a voltmeter and a lot of searching. With your system running loud, measure volts at alt, at battery, at fuse box, at amps etc., etc. You'll find the places where voltage drops.
I'm running a whole lot more power and i have to go beyond the pain theshold before i can get the lights to dim on idle. no dimming at all at 2k rpm. That's why i still suspect a connection problem.

Edit: Your truck is brand new, Tell the dealer that your alt is bad. They can test it at idle and under load.

You keep mentioning that your amp is clipping. How high are your gains set?

Improperly set gains can cause dimming. For about a day my lights would dim at high volume, so I broke out the voltmeter and set my gain properly. No more dimming. This is with a class d 400W rms amp and the stock 140 amp alternator.

Okay folks, I found the problem and I still can't explain it. Maybe someone here can.

Since I couldn't find the problem I upgraded my amp from a power acoustic 520w, gothic series amp, to a Rockford Fosgate P325.1. When I connected the RF amp, it wouldn't power up. I reconnected the PA amp and it would work, so this was very baffling. I knew my power and grounds were solid. So I'm thinking the REM connection is bad. So I ran a short piece of wire from the battery terminal to the REM terminal and the RF amp powered up! I then moved the REM to a source in the fuse box as opposed to the back of the deck.

Interesting how the connection was good for the PA amp and no good for the RF amp.

My interior lights, nor my headlights dim when the bass hits. They only dim when I use the electric windows. It's not bad, so I'm not going to worry with it.

No more clipping.

REM Terminal – The heavy duty, nickel-plated captive c-clamp wire connector will accept wire sizes from 12 AWG to 24 AWG.This terminal is used to remotely turn-on and turn-off the amplifier when +12V DC is applied.

^^^^^
Out of the amp manual.

If your deck is not supplying enough on the remote wire the amp won't turn on.
I remember older decks were like 2v or something.

And I guess I was more or less correct that a proper class BD in your case solved your issues just like it did in my situation.