? for the audio guru's.

I've got two 12'' subs powered by a 342 MTX amp. I've noticed that when the bass hits hard, the light output from my headlights dims a tiny bit. I know for a fact that my battery isn't that great. (left the dome light on overnight a few times in the past) But is it really the batt?

What's the problem and how can I fix it?

 

More than likely your setup is pulling too many amps when the bass hits. Pretty much it's going to want power, takes from the battery but the altenator is going to take a split second to output more amps to the system. If its not that bad at all, a band-aid fix would be to buy a capacitor. It will store power and releases it really quickly when the bass needs it and stores more power again after discharge... That's not the full solution though, it would just help smooth out the drain on the elec. system for the most part from what I've gathered. A good solution would be to get a higher output altenator and a battery that is designed for audio setups. I'm sure more people will contribute better info to you on this matter, this is just my .02 on what i've gathered over the months on here.

 

^what he said. also a possible big 3 upgrade may help. which essentially is VERY ARGUABLY "effective" as the cap is. i did both. lol

 

i just looked up the amp you have... at max you are pushing 340w. i am running 400 and have yet to have any dimming problems. what gauge wire are you using out of curiosity?

 

I don't know. Its an old amp kit I've had for a while. What is standard? Its not that heavy.

Thanks for the info so far guys. What is this 'big 3' upgrade?

 

thats a good point, I was pulling 400W on 4gauge and I didnt get any dimming (not sure how but I wasnt) I didnt have a sub but I had 4 powered speakers, two of which were component setups with 6.5" "subs"

 

theres no real "standard" per se. but for safety on a basic set up youd wanna run at least 4awg to the trunk, then into a distro block if you need 8awg. but definately do 4awg run to the trunk for power and your ground (ground can be anywhere and doesnt necessarily have to be ran from the battery).

the big 3 consists of adding 2 grounds and connecting an extra power line. 1. is connecting the negative on your battery to a chasis ground. 2. is your engine to a chasis ground. and finally 3. is connecting the positive on your battery to the positive on your alternator. this is usually done with 0awg wiring, but do not go as low as 4awg (i use 4awg since i had extra wires. lol)

i think golden86 is running at 600w at 2ohms with the same amp i have and says he has no dimming problems. as to how he did it i have no idea. haha. i tried running 600 and had dimming each time my bass kicked. so definately at 340 shouldnt be too heavy with the dimming. note i am also running 9005 headlights (+20w) instead so thats even taking up more power, and yet i still dont have dimming . just might check your connections and what not that everything is clean and make sure that your grounds are good too.

 

Cool thanks a lot guys.

 

Do the big 3 and get a cap if you still need it

 

Here's the "Big 3 Upgrade" - that EVERY Scion owner should do:

http://www.the12volt.com/installbay/...TID=73496&PN=1

The "Big 3 Upgrade" is replacing the small wires car manufacturers use for larger ones and thus better performance. When Matt and I upgraded the tC's wires, we were shocked (pardon the pun) at how much smoother the engine ran, and it no doubt helped the stereo. The goal of the upgrade is to lower resistance by increasing the wire size between critical components - alternator, battery, chassis, etc.

The OEM battery is fine for most systems...no need to "upgrade". Most amplifiers have enough internal capacitance to withstand even the most demanding bass tracks, and external caps are only a band aid fix, provided you've got the proper size power cables to the amps. Again, upgrading the "big 3" is key, and 99% of the time will cure any head light dimming, etc.

The problem with adding a capacitor is it's an additional energy storage device that must recharge every time the amplifier draws energy from it. Of course, the amplifier is trying to recharge it's own internal capacitors, so with the addition of the external cap, the alternator has three devices (battery, cap, amp) to charge, PLUS supply enough energy to sustain the car's normal operation - headlights, tail lights, A/C blower, etc.

 

Upgrading the wiring is definitely the first thing I'd recommend. After that if you are still experiencing problems, an upgraded alternator is the next best step.

As mentioned a couple of times, a capacitor is really only a band aid to larger problems. Don't waste the money on one!

 

I was reading the 12volt.com guide to doing the Big 3...I didn't know you needed to solder anything to do the upgrade on the tC. Is there a way to do it without soldering?

 

I've never heard of it needing soldering. The thread I read on it was just using wires crimped into the circle like connectors, with heat shrink wrapping to water protect them. Then connecting at different parts of the car. I realize this is a lot to read but I did it and it has setups in it for the tC https://www.scionlife.com/forums/viewtopic.php?t=29261

Have fun :D

 

what did it say to solder? i only soldered the tips to keep the wire from falling out.. lol

 

6. You may need to use a vise or some other set of "helping hands" to hold the cable while you solder it. Heat your soldering iron and place it on the connector (on the lug side) barrel. Hold a piece of solder against the tip of the iron and melt the solder into the strands of the cable. Use sufficient solder to fill the connector and completely cover all strands of the cable. NOTE: the lug will get hot and will burn you if you try to hold it. Also, if the insulation on the cable starts to melt, you are over-heating the cable and not paying attention to melting the solder into the cable. You do not need to try and melt the cable!

 

i think thats if you wanna lock it in like i did. i didnt have a good 4awg crimper so i used what i had, then i soldered it ot make sure that it dint fall out.

 

Ah but if you use 0g...it shouldn't fall out?

 

if you dont or cant crimp it right then it will. soldering will lock it in so it wont fall out. even if the crimp fails, itll still be stuck in there.

 

I suppose soldering isn't a big deal anyways. I have a butane powered soldering iron so portability isn't an issue...

 

do the big 3 first i would say which is your - on your battery to ground. your batter + to your alternator power and then to ground your engine block
after big 3 if its still bad which it shouldnt then i would say get a dry cell battery like optima or kinetic
then alternator. like said before its arguable caps arents needed and i dont feel there needed