Hey guys,
I have a rather old car (1988 560 SEL Benz) and the new soundsystem I installed in it is putting quite a strain on the alternator (dimming lights whenever bass hits). I already bought a 3 farad capacitor to help the strain but I was thinking...couldn't I just put in another car battery? I could just parallel a new battery to my old one. Any reason why this wouldn't work? Please let me know! Oh my soundsystem power drain is about 800W
-Segasonicfan
I have a rather old car (1988 560 SEL Benz) and the new soundsystem I installed in it is putting quite a strain on the alternator (dimming lights whenever bass hits). I already bought a 3 farad capacitor to help the strain but I was thinking...couldn't I just put in another car battery? I could just parallel a new battery to my old one. Any reason why this wouldn't work? Please let me know! Oh my soundsystem power drain is about 800W
-Segasonicfan
YES!!
Not only can you put in an extra battery in parallel, you definately should. You might find that it is sufficient to prevent the lights from dimming and then you might get to return the capacitor. You could even put more than one extra battery. Note, that it is best to place the battery as close to the amplifier as possible.
Not only can you put in an extra battery in parallel, you definately should. You might find that it is sufficient to prevent the lights from dimming and then you might get to return the capacitor. You could even put more than one extra battery. Note, that it is best to place the battery as close to the amplifier as possible.
Hey thanks so much Nafta 
I'm actually using a bunch of amps: 1 Infinity 7520a, 1 Lightning Audio, 2 250W Crunch amps, and my pioneer in-deck receiver amp. I might also be adding my own amps to the system. As to the gauge of the cable, I'm using 20AWG to everything since I got a bunch of it bulk for a great price. It's coaxial and has great woven grounding insulation so I think it has great audio and power use (expecially cause it's solid).
-Segasonicfan
I'm actually using a bunch of amps: 1 Infinity 7520a, 1 Lightning Audio, 2 250W Crunch amps, and my pioneer in-deck receiver amp. I might also be adding my own amps to the system. As to the gauge of the cable, I'm using 20AWG to everything since I got a bunch of it bulk for a great price. It's coaxial and has great woven grounding insulation so I think it has great audio and power use (expecially cause it's solid).
-Segasonicfan
Wrong on all counts, if it's for power.
20 guage is way small for anything over a few watts. IASCA has a chart for this. You may be dropping as much as a couple of your 14 volts right across the wire, depending on the current. Not to mention the risk of fire. It would be an urban legend but I actually read the article myself... a fireman of all people had his car burn to the ground because of too-small power leads to his amplifiers and they heated up, melted the insulation, caught fire...
"they" tell us that current travels more on the outside of the wire "skin effect"... stranded wire = better for high current...
so you want MUCH bigger, stranded wire for power.
Another battery wouldn't hurt unless you install it wrong. Part of "wrong" is "without its own fuse within 18" ".
What you really want is a bigger alternator. I can't see stock parts from way back then being rated for lotsa watts for your sound system. Another battery is only a bandaid like the capacitor is a bandaid, and will be prone to the same not-helping effect, besides taking up more room. A new alternator is the solution to high current demands, and takes up almost no additional space.
HTH
-David
20 guage is way small for anything over a few watts. IASCA has a chart for this. You may be dropping as much as a couple of your 14 volts right across the wire, depending on the current. Not to mention the risk of fire. It would be an urban legend but I actually read the article myself... a fireman of all people had his car burn to the ground because of too-small power leads to his amplifiers and they heated up, melted the insulation, caught fire...
"they" tell us that current travels more on the outside of the wire "skin effect"... stranded wire = better for high current...
so you want MUCH bigger, stranded wire for power.
Another battery wouldn't hurt unless you install it wrong. Part of "wrong" is "without its own fuse within 18" ".
What you really want is a bigger alternator. I can't see stock parts from way back then being rated for lotsa watts for your sound system. Another battery is only a bandaid like the capacitor is a bandaid, and will be prone to the same not-helping effect, besides taking up more room. A new alternator is the solution to high current demands, and takes up almost no additional space.
HTH
-David
Thanks for your insight stocker. Unfortunately a new alternator isn't a possibility. The cost of a fitting my Mercedes with a new one wold be staggering-more than my soundsystem itself :/ And while the capacitors and the extra battery may be a bandaid, they are very good ones. Once the caps (and extra battery) are charged they should have enough power to pump out to the sound system for a while.
That's strange what you said about the gauge of wire though....I've never found the 20AWG to be heated in the slightest, even when running to the 250W amp. It doesn't make much sense to me that a hugher gauge would be required for safety when smaller gauges are run throughout my entire car at 12v running to everything from the original 10A soundsystem to the powerful window motors and other amps. I have a household heater that pumps out 1500W that has wire heating issues, but that's about double my soundsystem power and I've used less than 20AWG with it. I think something else must've burned that guys car down....
I always fuse the hell out of everything I have so I will definitely do so with the new battery. All my amps have at least one fuse a piece not to mention that the 12v battery and 12v signal lines are all fused (along with everything else) to my cars fusebox.
-Segasonicfan
That's strange what you said about the gauge of wire though....I've never found the 20AWG to be heated in the slightest, even when running to the 250W amp. It doesn't make much sense to me that a hugher gauge would be required for safety when smaller gauges are run throughout my entire car at 12v running to everything from the original 10A soundsystem to the powerful window motors and other amps. I have a household heater that pumps out 1500W that has wire heating issues, but that's about double my soundsystem power and I've used less than 20AWG with it. I think something else must've burned that guys car down....
I always fuse the hell out of everything I have so I will definitely do so with the new battery. All my amps have at least one fuse a piece not to mention that the 12v battery and 12v signal lines are all fused (along with everything else) to my cars fusebox.
-Segasonicfan
stocker is not kidding about the 20 ga coax for your main power to the amps-the cable is mainly used for low volt situations,not only is it going to sound worse it is dangerous-replace it with at least 4 gauge from batt to a disto near your amps and split it off with 8 ga.-for sub amp- or 10ga. to mid-high to ea amp,spend a few dollars it will sound better and you and your car will live longer. 
Well maybe it would improve the sound quality but I certainly don't think it's a fire hazard. I can't even find a 12v power line in the car larger than 24AWG and I would have to take about the entire dash (at the very least) to run wire directly from the new battery. So even if I do use 18AWG if will be connected to an internal 24AWG line or less coming from the battery not to mention the other 12v line coming from the remote which is also 24AWG or smaller.
-Segasonicfan
-Segasonicfan
Wait, your power cable isn't even running straight to the battery?
This is basic stuff man, I hate to be so honest, but you should know better. Just the IDLE current from those amps is around the maximum that 24awg can handle, if you play any music, anything at all, you're exceeding the maximum current carrying capability of the power wire. 20awg can hold around 2 amps effectively (for power transmission) and around 10 amps safely. You're grossly exceeding both of those in your current setup. I don't know why can't find anything larger than 24awg in your car, my car has a 6awg coming off of the battery that goes straight to the starter, and a seperate 8awg coming off the battery that powers the windows, headunit, lights, etc. The power windows have ~12awg power, the headunit has ~16awg power...there are "large" cables all over. Your 20awg power is seriously a fire hazard, especially if you have it connected to a 24awg power lead in the dash.
Go in and run a 4awg cable straight from the battery to the trunk, then you can use a fused distribution block to split it to a few 8awg cables for your amps.
This is basic stuff man, I hate to be so honest, but you should know better. Just the IDLE current from those amps is around the maximum that 24awg can handle, if you play any music, anything at all, you're exceeding the maximum current carrying capability of the power wire. 20awg can hold around 2 amps effectively (for power transmission) and around 10 amps safely. You're grossly exceeding both of those in your current setup. I don't know why can't find anything larger than 24awg in your car, my car has a 6awg coming off of the battery that goes straight to the starter, and a seperate 8awg coming off the battery that powers the windows, headunit, lights, etc. The power windows have ~12awg power, the headunit has ~16awg power...there are "large" cables all over. Your 20awg power is seriously a fire hazard, especially if you have it connected to a 24awg power lead in the dash.
Go in and run a 4awg cable straight from the battery to the trunk, then you can use a fused distribution block to split it to a few 8awg cables for your amps.
Alright, alright I'll use some larger wire. It may be basic stuff but like I said everything in the dash and all the stuff running to the power windows, heaters, etc is 20AWG or smaller. I guess my car is just too damn old...heh. It's just SUCH a pain to run wire directly from the battery because that means I have to pull apart the whole dash to run wire from the interior to under the front hood (where the battery is). Oh well..... :/
-Segasonicfan
-Segasonicfan
I haven't found a vehicle yet where it's really that hard, then again I've only worked on newer cars and most of them have holes already cut in the firewall with grommets that you can just slit open and use at will. 4awg still isn't that bad though, I've got 0awg in my car, that was a little interesting running through the cabin inconspicuously.
Also, a good, cheap fix for dimming problems is something called the big 3. It's just 3 cables under the hood that you can upgrade to improve the efficiency of the car's electrical system, namely the battery - to chassis, engine block to chassis, and battery + to alternator. Doing this (especially the batt - to chassis) won't always completely cure dimming, but it will significantly help almost every time.
Also, a good, cheap fix for dimming problems is something called the big 3. It's just 3 cables under the hood that you can upgrade to improve the efficiency of the car's electrical system, namely the battery - to chassis, engine block to chassis, and battery + to alternator. Doing this (especially the batt - to chassis) won't always completely cure dimming, but it will significantly help almost every time.
thanks sr20demon My god, 0AWG through the interior must've looked like a giant snake...lol. Well, I guess I'll do a 4AWG for the power lines then. Should I use thick wire for the amp outputs too? I'm trying to preserve the audio quality with insulated wire. I'll use my 20AWW coaxial stuff for the preamp outputs anyway...but it looks like buying 100' of that was a waste lol. I'll have to drive by home depot to pick up the thick stuff.
and yeah, I'm sure newer cars are wayyy easier. Older cars (especially below 1990) are hell to work with.
-Segasonicfan
My god, 0AWG through the interior must've looked like a giant snake...lol. Well, I guess I'll do a 4AWG for the power lines then. Should I use thick wire for the amp outputs too? I'm trying to preserve the audio quality with insulated wire. I'll use my 20AWW coaxial stuff for the preamp outputs anyway...but it looks like buying 100' of that was a waste lol. I'll have to drive by home depot to pick up the thick stuff. and yeah, I'm sure newer cars are wayyy easier. Older cars (especially below 1990) are hell to work with.
-Segasonicfan
For mids/highs I generally use 16awg and for sub(s) I generally use 12awg, but it all depends on how much power you're sending them and at what impedance. Right now I've got 18awg for the tweets (100x2 @ 4ohm, though I never use anywhere near that), 16awg for the mids (250x2 @ 4ohm, though I never use that much), and 10awg for the sub (1500rms @ 1ohm = lots of current)
holy crap, where did you get a sub at 1 ohm with 1500w rms? I presume that's 4 subs connected parallel. Still, that's 375w a piece...very nice! Your car must shake the earth though...lol
I don't use a whole ton of power for anything but the subs. I'm more about quality not quantity. The most I ever pump out of any midrange/ tweeters is 40-50watts. The subs are 250w a piece though. Thanks for the recommendations. Also, what voltage caps for the crossovers do you think I should use? I'm not sure if the audio signal is mainly pushed by voltage or current (I'm guessing mostly current though since these are running off 12v). There's a DC-DC conver inside my amps that pushes out 25v so I'm thinking 50v should do it? Or should I get 100v to be safe?
-Segasonicfan
I don't use a whole ton of power for anything but the subs. I'm more about quality not quantity. The most I ever pump out of any midrange/ tweeters is 40-50watts. The subs are 250w a piece though. Thanks for the recommendations. Also, what voltage caps for the crossovers do you think I should use? I'm not sure if the audio signal is mainly pushed by voltage or current (I'm guessing mostly current though since these are running off 12v). There's a DC-DC conver inside my amps that pushes out 25v so I'm thinking 50v should do it? Or should I get 100v to be safe?
-Segasonicfan
100V crossover caps will not hurt anything besides the wallet.
Too low will have an annoying tendency of catching fire or letting out noxious fumes and killing tweeters.
To clarify and expand on the power wiring:
Go to even any rathole car audio shop for low prices (knowing what is a low price first is mandatory) or ask a freind/neighbour who is upgrading if you can have their old stuff, or go to (e.g.) Partsexpress.com for the following... high power wire is also to be found in welding shops if you prefer.
Get:
+enough RED 4AWG to get to your distribution block plus a couple/few feet for ooopsies
+enough BLACK 4AWG to get from the battery to the engine block or the chassis
+enough RED 8AWG to get from the distribution block to the amps
+enough BLACK 8AWG to get from the amps to wherever you are grounding the amps nearby
+a fused distribution block with a fuse per amplifier OR at least a non-fused distribution block with enough properly-sized terminals for the number of amps you have
Connectors for:
+4AWG to battery terminal x2
+4AWG to ground lug x1 (or more depending on how crazy you get with the grounding
+grounding lugs (ring terminals or spade terminals) for all the ground and power connections that need them
and MOST important:
+1x REALLY BIG fuse holder to put someplace solidly mounted within 18" of the battery's (+) terminal. You can screw the rest of the wiring up, but get this right. This WILL prevent your car burning down (and was missing from our fireman's install) and is a requirement to be considered even a marginally safe installation of any aftermarket amplifier. add up the fuse ratings on all the individual amps, and get that size fuse to put in this fuse holder. Mine is rated for 100A
All of this should set you back around $50 or less if properly sourced and can save your car, your life and your pride.
Please understand that we are trying to look out for your and your car's safety here...
p.s., car audio installations done properly take a little time and a lot of hassle usually. Accepting this or not is the difference between knowing you did a good job, a bad job, or forked out $40-60/hr for labor to someone else for something you could have done yourself.
-David
Too low will have an annoying tendency of catching fire or letting out noxious fumes and killing tweeters.
To clarify and expand on the power wiring:
Go to even any rathole car audio shop for low prices (knowing what is a low price first is mandatory) or ask a freind/neighbour who is upgrading if you can have their old stuff, or go to (e.g.) Partsexpress.com for the following... high power wire is also to be found in welding shops if you prefer.
Get:
+enough RED 4AWG to get to your distribution block plus a couple/few feet for ooopsies
+enough BLACK 4AWG to get from the battery to the engine block or the chassis
+enough RED 8AWG to get from the distribution block to the amps
+enough BLACK 8AWG to get from the amps to wherever you are grounding the amps nearby
+a fused distribution block with a fuse per amplifier OR at least a non-fused distribution block with enough properly-sized terminals for the number of amps you have
Connectors for:
+4AWG to battery terminal x2
+4AWG to ground lug x1 (or more depending on how crazy you get with the grounding
+grounding lugs (ring terminals or spade terminals) for all the ground and power connections that need them
and MOST important:
+1x REALLY BIG fuse holder to put someplace solidly mounted within 18" of the battery's (+) terminal. You can screw the rest of the wiring up, but get this right. This WILL prevent your car burning down (and was missing from our fireman's install) and is a requirement to be considered even a marginally safe installation of any aftermarket amplifier. add up the fuse ratings on all the individual amps, and get that size fuse to put in this fuse holder. Mine is rated for 100A
All of this should set you back around $50 or less if properly sourced and can save your car, your life and your pride.
Please understand that we are trying to look out for your and your car's safety here...
p.s., car audio installations done properly take a little time and a lot of hassle usually. Accepting this or not is the difference between knowing you did a good job, a bad job, or forked out $40-60/hr for labor to someone else for something you could have done yourself.
-David
segasonicfan said:
Adire Brahma 15
For normal listening it's turned down so that it's balanced with the front stage though
Stocker made good points in his post. One thing to clarify though, watch out on fusing. For the main fuse, you can add together the fuse rating of each of the amps running off that cable and use that for your fuse, but just make sure that value is smaller than the maximum current that size wire is capable of carrying, for 4awg this is around 125-140 amps. If you use a distribution block to step down wire size, unless your primary fuse is small enough to still offer protection for these new smaller wires, you should use a fused distro with the proper sized fuses for your new wires, for 8awg it is around 80amps.
OK I picked up all the wire yesterday. Home Depot has suprisingly cheap stuff. I bought 6AWG for the batt (600W is probably the most I'll use of my system anyway), 10AWG for the subs, and 14AWG for the res of the speakers (which are all under 100W max). Now I just have to get the fuse, another battery, and wait for my 3 farad caps to come in the mail!
-Segasonicfan
-Segasonicfan
That is like saying a house is just a load on the foundation... the response is "well yes, depending on your perspective, but...".
If you need a little bit more energy for qiuck transient bass notes than your charging system will provide, a capacitor is one "band-aid" way to fix it. When discharged, yes they are a load until charged again, but the rest of the stereo is "just" a load on the electrical system as well. Some loads we tolerate because we like what happens when we carry then, no?
If you need a little bit more energy for qiuck transient bass notes than your charging system will provide, a capacitor is one "band-aid" way to fix it. When discharged, yes they are a load until charged again, but the rest of the stereo is "just" a load on the electrical system as well. Some loads we tolerate because we like what happens when we carry then, no?
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