Big 3 upgrade? (Car Audio)

[miztahsparklez]

I've looked around the forum and it seems that the general consensus that the big 3 is not needed in our cars, but I beg to differ. I haven't had a poke around the engine and follow the cable back to the trunk, but has anyone done the upgrade? specifically, the battery to alternator cable?

I'm considering running 0GA to the trunk, as I seem to be having excessive power draw from my stereo, shutting components off when the bass hits during loud volume. I suppose my battery or something has weakened over time, as this wasn't an issue when I first put in the system.

I've already added a 1 farad capacitor to try to help smooth out the power dips, but it seems like the issue is more of a power draw over time. Dynamics have increased, but power going to my sound processor isn't sufficient enough to keep it alive, resulting in it shutting down everything.

I've also tried rewiring my remote turn on wires up to a relay instead of juicing from the sound processor, but it doesn't have seemed to have much of an effect.

[S4-Rob]

I take delivery of my 2014 in 2 weeks and I plan to put a reasonable stereo in as well. I have had extreme competition vehicles in the past and really would not feel comfortable interfering with the big three in this vehicle. Too many ways to TD1 yourself IMHO. My intent is to use a 20f cap to smooth out the power requirements, but my system (as I have the components sitting in my living room is only about 1800 watts. What king of power are you drawing that would actually shut components down? Have you considered a dual output alternator and second battery to keep the factory and aftermarket path's separate? If you upgrade the alt/bat cable, I would suggest a second battery and isolator, just to avoid touching the stock system. That's just me. (of course, I say this, and I have my ECU tune scheduled for 3 weeks from now, which will TD1 me automatically)

[Mbrad]

Miztah,

I had a bunch of similar issues but figured out that it was not power in that was the problem. It was an overvoltage protection on the output of my amp that was causing the amp to shut down. My guess (based on a bunch of fiddling) is that there is an impedance drop in the stock midbase/bass front door speakers at increased power. If I ran loud, my amp went down. Turned down gains, an problem was solved. Also, removed the connection to those speakers from the amp and could run full power into my replacement dash speakers/tweeters. Recently upgraded door speakers and can now run full on gain with no shutting off. Long winded response to show that I that at least in my case, the issue was the speaker, not the power draw (granted, I only have a 700 watt amp in (in addition to the stock one)). If your running more power, my point may be irrelevant.

On a related issue .... I have peppered the guys at Hybrid audio and am an inch away from getting LS6's for the doors if they work/fit. NEVER have I heard a midbass that good!

[Deckdout2]

Take out that useless farad cap. It will do more harm then good. If you want to really beef up your power delivery, find someone that will recoil your alternator. Or find a bigger one that will fit. You're going to kill your alternator and your battery using a farad cap. They do nothing for systems except drain them, and it's not the 90's anymore......

[infinkc]

I dont think the 0ga wire will do much. Like mentioned above you should get your alternator rebuilt to output more current. Your problem however sounds more like a grounding issue for the amps. Have you checked to make sure that they are tigntened down enough on bare metal? That or the amps are going into protection mode from being overworked.

What battery are you using the stock one?

[riegeraudi]

Take out that useless farad cap. It will do more harm then good. If you want to really beef up your power delivery, find someone that will recoil your alternator. Or find a bigger one that will fit. You're going to kill your alternator and your battery using a farad cap. They do nothing for systems except drain them, and it's not the 90's anymore......

The Farad cap won't kill your alternator. I have had one in my B5 for 13 years and everything is still working. Without it my bass sounded like mush. With it much punchier and controlled bass.

[Alipor]

I've looked around the forum and it seems that the general consensus that the big 3 is not needed in our cars, but I beg to differ. I haven't had a poke around the engine and follow the cable back to the trunk, but has anyone done the upgrade? specifically, the battery to alternator cable?

I'm considering running 0GA to the trunk, as I seem to be having excessive power draw from my stereo, shutting components off when the bass hits during loud volume. I suppose my battery or something has weakened over time, as this wasn't an issue when I first put in the system.

I've already added a 1 farad capacitor to try to help smooth out the power dips, but it seems like the issue is more of a power draw over time. Dynamics have increased, but power going to my sound processor isn't sufficient enough to keep it alive, resulting in it shutting down everything.

I've also tried rewiring my remote turn on wires up to a relay instead of juicing from the sound processor, but it doesn't have seemed to have much of an effect.

How many watts is your system? I would check your grounds first.

[gendry]

What's the concern with the cap? I get the leakage current could drain the battery over an extended period of time not using the car, but I have no idea on the order of magnitudes of power drainage to have any clue whether the drain is fast enough to matter in the real world. Its not like the cap is the only existing source of leakage current. Also, how does it hurt the alternator?

I had a 1 farad cap in my old Nissan in undergrad when I was getting a degree in EE (I probably did it more for novelty than utility, but it was a big cap!) and never had a problem - nor any voltage drops under load.

Take out that useless farad cap. It will do more harm then good. If you want to really beef up your power delivery, find someone that will recoil your alternator. Or find a bigger one that will fit. You're going to kill your alternator and your battery using a farad cap. They do nothing for systems except drain them, and it's not the 90's anymore......

[steve trac]

can someone please explain what the big 3 are? the power wires going to/from what, what and what? Thanks.

[Alipor]

can someone please explain what the big 3 are? the power wires going to/from what, what and what? Thanks.

Big 3, 0gauge from alt to battery, Bigger alternator, and battery.

As for caps, check out this thread. For the money for most, i'd rather have a second quick discharge small battery instead of a cap.

http://www.diymobileaudio.com/forum/...ste-money.html

[gendry]

As someone with an EE degree I can say that some of the info from the link in that thread is quite wrong on very basic levels. "The capacitor are electrical buffering devices. They are not current-generating devices." - yeah caps can provide current. That's the way they (temporarily) resist voltage changes. Me thinks the author should take a charged 1 farad cap, disconnect it from the circuit, then short the terminals. That big bang you then see that probably melted the terminals? That's current buddy. Way more current than a battery can provide at max discharge rate. The ability to spark like that is how you the cap keeps the voltage in the car high even in short bursts of high power draw from a crazy sound system.

I think the author found out the hard way that a cap isn't a battery and won't increase max SUSTAINED current draw even with an alternator on and decided caps are useless.

I know more about caps than I do alternators, but I always assumed that swinging the alternator load from low to beyond max (and thus letting the voltage drop) between every audio beat was bad for it long term.

"Sounds like the author that he would get a cap as a battery backup and then realized they don't work that way and was disappointed. AFAIKT, the cap is great if you have a power draw larger than the battery's max discharge rate at its peak (or the battery + alternator)

Big 3, 0gauge from alt to battery, Bigger alternator, and battery.

As for caps, check out this thread. For the money for most, i'd rather have a second quick discharge small battery instead of a cap.

http://www.diymobileaudio.com/forum/...ste-money.html

[gendry]

a second discharge small battery for what purpose? If the purpose is to increase the max power stored for use when engine is off, sure that's a good idea.

If the purpose is to increase the max current able to be provided at any given instant (say when you are on beat and the subs dim the light), then a large cap will temporarily provide far more current.

Or is there another purpose I am missing?

[miztahsparklez]

Considering I was able to run the same system in a 04 C230K, with one additional amp, something's not quite right here. This car i had 0GA going from the battery (in front) to the trunk.

I'm actually running LESS power now than i was previously. As for speakers, most are 8ohms in my system. Nothing is stock except the MMI. I run 7" speakers in the doors.

When i was running full class A/B in my Acura, I had my alternator redone for 120A. Also had an overdrive pulley on it. However, the change to Alpine's PDX series should have had a significant drop in power requirements.

I know there's an obvious voltage drop issue to the rear, as I measure 14.4 up front, while the rear reads mid to low 12s and under at times, which is why I'm suspecting the cable is insufficient for my needs.

Again, I'm not using the cap to magically "gain more power". I'm using it to level the load and clean out some of the dips and valleys during bass hits. Caps are more responsive to delivering power than say a battery is. Directly pounding on your alternator probably isn't very good for your regulator either. Providing a consistent draw of power from your alternator will help it gear up for the current demands. A drop in voltage signals the regulator to produce more, then as the bass subsides, you end up with an over voltage situation, prompting the alternator to stop producing, just as the bass hits again, forcing the voltage spikes to be increasingly massive.

Recoiling your alternator does nothing when your pipe is only so big. Imagine having a huge lake full of water. If you're only sucking through a straw, what's the point? Yes, I'm on the stock battery. The car is a 2012, so should be good still.

I'll recheck my grounds. Seems like it could have rattled loose. I'm using one of the factory bolts in the spare tire well. They have acorn nuts on them. Not sure what they're used for, but seemed to work decently initially anyway. One thing I did notice while inspecting some wires was that one of my grounds leading back to my distribution block had melted through the sheath and grounded itself out on the bolt in question. I've replaced that cable and put loom over it now.

My draw is minor. 2200WRMS, more than most people, but not quite up there with the big hitters. Plus they are all class D.

[Alipor]

Considering I was able to run the same system in a 04 C230K, with one additional amp, something's not quite right here. This car i had 0GA going from the battery (in front) to the trunk.

I'm actually running LESS power now than i was previously. As for speakers, most are 8ohms in my system. Nothing is stock except the MMI. I run 7" speakers in the doors.

When i was running full class A/B in my Acura, I had my alternator redone for 120A. Also had an overdrive pulley on it. However, the change to Alpine's PDX series should have had a significant drop in power requirements.

I know there's an obvious voltage drop issue to the rear, as I measure 14.4 up front, while the rear reads mid to low 12s and under at times, which is why I'm suspecting the cable is insufficient for my needs.

Again, I'm not using the cap to magically "gain more power". I'm using it to level the load and clean out some of the dips and valleys during bass hits. Caps are more responsive to delivering power than say a battery is. Directly pounding on your alternator probably isn't very good for your regulator either. Providing a consistent draw of power from your alternator will help it gear up for the current demands. A drop in voltage signals the regulator to produce more, then as the bass subsides, you end up with an over voltage situation, prompting the alternator to stop producing, just as the bass hits again, forcing the voltage spikes to be increasingly massive.

Recoiling your alternator does nothing when your pipe is only so big. Imagine having a huge lake full of water. If you're only sucking through a straw, what's the point? Yes, I'm on the stock battery. The car is a 2012, so should be good still.

I'll recheck my grounds. Seems like it could have rattled loose. I'm using one of the factory bolts in the spare tire well. They have acorn nuts on them. Not sure what they're used for, but seemed to work decently initially anyway. One thing I did notice while inspecting some wires was that one of my grounds leading back to my distribution block had melted through the sheath and grounded itself out on the bolt in question. I've replaced that cable and put loom over it now.

My draw is minor. 2200WRMS, more than most people, but not quite up there with the big hitters. Plus they are all class D.

2200WRMS is a bit, but good thing the alternator in the S4 is 150 amp so that is pretty big to start with. Your system has a higher RMS than mine, on my two stock systems, I run a PDX-V9 with no problem on the stock alt and battery. I found a way to figure out if your alternator was up to that load somewhere online, let me look around and see if I can find it again. But IIRC 120amp alt should do ~3000RMS. I'm just learning about all this, I think Gendry as an EE would be much more help.

[Alipor]

a second discharge small battery for what purpose? If the purpose is to increase the max power stored for use when engine is off, sure that's a good idea.

If the purpose is to increase the max current able to be provided at any given instant (say when you are on beat and the subs dim the light), then a large cap will temporarily provide far more current.

Or is there another purpose I am missing?

I'm not 100% sure but what I've been reading on the audio forum, if you have a quick discharge battery as a secondary, it will be able to absorb the multi hits of bass or large peaks better than a capacitor, and my theory on this is that once you discharge the cap, the battery has to replace the wattage, which will pull from the battery, then if large enough the alternator still has to run to replace that amount also, just one be daisy chain. Is this incorrect in my assumption? I'm not a EE, just trying to learn more about this. I've had two different audio shops do my car stereo's both with the same amps, one used something like this http://stingerelectronics.com/produc...&CategoryID=11 but the battery was ~10 years old, in my other system all be it, I'm sure it has a larger alternator and battery they didn't use a cap or anything else. So that falls in the big three. However the car with the cap, I feel like if I spent the same money on a new battery I wouldn't have the issue, since the alternator is putting out 120amp+

[gendry]

In a very basic sense, you can think of a battery and a capacitor as the same kind of thing, they charge energy when a voltage is applied to their terminals and discharge their stored energy when the voltage at their terminals drop lower than what they are charged to. For both a battery and a cap, all their charged energy is provided by an alternator. In this sense, they are the same.

The key difference here is that the capacitor charges and discharges all its stored energy VERY quickly (I am talking seconds for a big cap and milli or micro seconds for the tiny caps used on circuit boards), while a battery can only discharge its stored energy slowly over time (minutes or hours). Think of the difference between how long it takes a block of ice to give off its cold verses when you open the freezer door and let the cold out. One potentially has a lot more cold to give off while melting while the other cools a room much faster but then is used up for awhile.

It is true that if you discharge the cap (which isn't happening if your voltage isn't dropping/lights not dimming), the battery and alternator have to kick in to recharge it. But a large cap should only discharge a small fraction of its stored energy on the beat and will be recharge during off beat times. So the result is a tiny voltage swing instead of a huge one and a more constant load to the alternator. Also, its the same principle for a second battery, whatever you discharge from the second battery will need to be recharged later by the main battery and/or alternator.

the take away is this: (1) if you need more overall power to be provided for extended periods of time, get a better alternator but (2) if your problem is only voltage drops on beat dimming headlights, get a capacitor (or a bigger alternator).

[miztahsparklez]

Strangely enough, after I made this post, my amps have stopped shutting themselves off. So I do think i have a loose connection somewhere. I'll have to track it down.

[miztahsparklez]

Sure enough, it was the ground nut. It loosened itself a good 1/4"

Potentially the heat from the exposed ground wire made it contract/expand. Great news for me, as now I don't have to run anymore cables!