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| Show, Shine, and Tunes! Great talk on keeping your car looking the very best, discussing appearance items, and audio |
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#1 (permalink) |
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Posts: n/a
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Can somebody help me understand this?
Why are the cables for installing car audio so goddamn thick? First off, on the Monster install kit i used to wire up my amp in my honda. What the hell is with the 1/2 inch thick ground wire, and 1/2 inch thick power cable? The cable is too thick to be attached to the amps terminal. In fact, i have to pull back the sleeve and cut about 80% of the thickness of the cable so i can get it in the terminal. Once in, it runs fine like that. instead of using this garden hose power cable can i just use #6 AWG solid copper core? Im talking the same stuff i used to wire up my hot tub. That stuff can handle to 40 amps, the HOT TUB's requirements are 115Volts and a maximum of 1,500 watts. I have a Kenwood KAC-6202, nothing fancy but it fits my application perfectly. it is only a 400w amp and realisticly probably wont do over 200watts. How many amperes does an amplifier like this need? And are these big fat braided wires really needed or can i go with a decent gauge solid copper cable instead? Hell, the monster ground wire is thicker than the entire 6-3 bundle that feeds my hot tub. Hell, lets think about the power requirements of my Home audio system Reciever, 840 at 8 ohms Subwoofers 800 at 8 ohms 2 channel amp, 400w at 8 ohms. Grand total of 2,040 total watts that can be generated. All of my equipment is fed into a stage 3 power filter which goes to a dedicated 20amp ckt that runs to the breaker with yer standard romex cabling. It works beautifully. Im not sure if car audio works differently when it comes to power requirements, but there has to be something better than these goddamn garden hoses i have running under my carpet. Plus, i dont have a very high opinion of ANY cables from the Monster brand. Help me out. Do i HAVE to use these fat ****ing cables or can i use solid core copper? |
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#2 (permalink) |
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Senior Member
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id run anything thats oxygen free copper. doesnt sound like you need much so id run like 8 awg. you want it to be as little resistance as possible. a lot of guys run welding cable for power wire and ground too.
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#3 (permalink) | |
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Posts: n/a
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Quote:
I plan on putting another amp in my honda and a sub, and i hate the fat ass cables that come with monster. Adding another amp i might see if i can get some high purity 6 gauge long grain copper cables. Thanks! |
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#4 (permalink) |
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Senior Member
Join Date: Nov 2004
Location: Murfreesboro, TN
Posts: 1,788
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yea I hate 0/1 gauge and other thick wires. I run 8gauge with no problems.
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2003 DSG GT 5-speed Hellion 62mm and Flowmaster catback..... My bonestock 2v engine had been through 2 years of NX 100 shot, 3 years running 8-12lbs vortech s-trim, got into boost daily while racing on the weekends, had 157,000 miles on it, and was running like new |
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#5 (permalink) |
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Super Moderator
Join Date: Sep 2004
Posts: 5,416
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If its too thick and you have the cable you can strip the insulation cut some of the braided wiring if its too thick then use shrink wrap tubing to cover the bare wiring for a clean and safe install.
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#6 (permalink) |
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Senior Member
Join Date: Sep 2004
Location: Ft Wayne, IN
Posts: 1,093
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Generally the larger cable are using is for multi amp applications. You run the 2 gauge or whatever you have into a distribution block then run 8 gauge to each amp.
But in most cases brand doesnt matter, its all made in the same plants on the lines with the same copper and compounds.
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#7 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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Don't confuse household voltage(120/240V AC) with car voltage (12.5-14V DC). Its like comparing apples to oranges. With your car running, say you have 14V DC. Voltage can be related to the "pressure" pushing the current flow(like pressure pushing water out of a hose). 14 Volts of pressure isn't that much...car audio requires lots of current...add to that the fact that with DC voltage, the electrons have to flow from the battery...thru the load(stereo components, lights, etc)...then back to battery. There is a lot of resistance in the wiring. So, those are the reasons why you need humongo cables for high current draw accessories in your car(also why you need huge fuses). Now, in your house............120V AC....you have a lot more "pressure" to push the current(electrons)...also AC voltage is back and forth(sine wave)...Therefore, smaller wires and circuit breakers can be used.
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#8 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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The foundation for a good system install is to run a large conductor from your battery back to the trunk to avoid voltage drops, and to carry the current your amps need. In the trunk, step the big wire down using a distribution block to smaller wires going to the amps. It is also recommended to have atleast 1 Farad of capacitance for every 1000W of amplifier power. Capacitors quickly store and release energy that your amps require when a bass note hits. This helps reduce the dimming headlights problem.
Don't skimp on the ground wire either! Add an extra ground from battery under the hood to the body of the car. Also use a heavy gauge wire to ground in the trunk. Match the trunk ground wire size with the large wire coming from the battery to the trunk. Like I said before, in DC circuits, the electrons have to flow thru the entire circuit......so a large power wire and whimpy ground wire isnt good. The small ground wire doesn't allow all the electrons back to the source(conventional current flow), negating the benefits of the heavy power wire. |
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#9 (permalink) |
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Senior Member
Join Date: Oct 2007
Location: Lake in the Hills, IL
Posts: 490
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have you resolved ur problem jack? its been over a year.... haha
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#11 (permalink) |
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Super Moderator
Join Date: Sep 2007
Posts: 9,926
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Dear god! This thread has been ressurected form the dead! IT HAS BECOME... ![]() Sorry andy, just kiddin, thanks for the good info! |
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#12 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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Sorry guys....didn't realize that this thread was over a year old.
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#13 (permalink) | |
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Senior Member
Join Date: Mar 2006
Location: California
Posts: 1,782
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Quote:
The reason for the huge cables is that a low voltage (DC) signal requires a lot of amperage to do the same amount of work. Ohms law: P=IV Power = Current x voltage say you want 500 watts for your car stereo (DC.) You need 35.7 amps on that 14 volts to get the power you need. 14volts x 35.7Amps = 500 watts now say you need the same 500 watts in your house (AC.) You only need 4.16 amps with the 120 volts. 120volts x 4.16Amps = 500 watts Also capacitors for car audio are a waste of money. If you put a capacitor on an already taxed DC electrical system, you are not helping any. In DC analysis capacitors are treated as shorts anyway. |
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#14 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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Not to start an arguement, but the voltage is the "pressure" that pushes the flow of electrons(current-measured in amperes) through the conductor. I'm an electrical engineer and work at an electrical utility company( I have a little background in that). Maybe you learned the water analogy differently???? Also, Ohm's Law is V=IxR. P=VI is a very good equation for this comparison though(I was trying to keep it simple and avoid even basic equations)...And capacitors are helpful in car audio systems. They aren't a majic fix for a weak battery, thin wires, weak alternator, etc....but in a properly designed system they really do help. I have had them in most of my systems. If they had no use, why would all competition vehicles use them? Aside from competition vehicles, my friend had a decent system in his car, with just marginal wiring. The headlights would dim like crazy...he installed a cap, and it eliminated about 75% of the dimming. Wasn't a bad fix for less than $100. Just ask Richard Clark about capacitors use in car audio. He introduced them into car audio back in the day and trademarked the term "stiffening capacitor". They also filter noise if present in the power cables.
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#15 (permalink) | |
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Senior Member
Join Date: Mar 2006
Location: California
Posts: 1,782
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Quote:
I= V/R I= P/V I= Square root of (P/R) R= V/I R= P/I^2 R= V^2/P P= V^2/R P= I^2 times R P= IV V= IR V= Square root of (PR) V= P/I More schooling for you when I have more time |
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#16 (permalink) |
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Super Moderator
Join Date: Sep 2007
Posts: 9,926
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#17 (permalink) | |
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Senior Member
Join Date: Mar 2006
Location: California
Posts: 1,782
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I know total nerd fight going on right?
http://en.wikipedia.org/wiki/Car_audio Quote:
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Last edited by Codiddy : 05-20-2008 at 04:25 PM. |
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#18 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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Don't bother "schooling" me....unless you have a master's degree in electrical engineering..... you don't even remember that voltage is "pressure"(you said amperage is pressure- WRONG grasshopper). You are just throwing out highschool level basic DC formulas. Look up OHM's law: V=IxR. A few pages in your text book later you will find the POWER formula, that you are so proud of. When you have the "time", maybe school yourself or keep quiet. Lets get back to cars now...................This is a nerd fight! I'm an electrical engineer now...but used to be a auto technician in my "cooler" days!
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#19 (permalink) |
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Senior Member
Join Date: Oct 2007
Location: Lake in the Hills, IL
Posts: 490
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i like turtles
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#20 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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Haha....yes, turtles are nice quiet littles creatures!
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#21 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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Just to beat a dead horse.....here's Richard Clark's reply:
Quote: Originally Posted by ANDYS87 Hi Richard, I've written you before. Was a huge fan of you and your "sound system" GN back in the good old days. Reasons why I went into electrical engineering.... Anyways, this guy on a Mustang forum(american muscle.com) is throwing out basic highschool DC formulas and trying to "school" me. There's always an ass**** out there! Anyways, he says that capacitors for car audio purposes are useless. You are the stiffening capacitor "GOD" so I thought I'd get your take on it. I will paste what he said below: .................................................. ...................... Actually if you are using the hose analogy, the amperage would be the pressure and voltage would be the diameter of the hose, not the pressure. The reason for the huge cables is that a low voltage (DC) signal requires a lot of amperage to do the same amount of work. Ohms law: P=IV Power = Current x voltage say you want 500 watts for your car stereo (DC.) You need 35.7 amps on that 14 volts to get the power you need. 14volts x 35.7Amps = 500 watts now say you need the same 500 watts in your house (AC.) You only need 4.16 amps with the 120 volts. 120volts x 4.16Amps = 500 watts Also capacitors for car audio are a waste of money. If you put a capacitor on an already taxed DC electrical system, you are not helping any. In DC analysis capacitors are treated as shorts anyway. __________________................................ ........... Ok, he thinks amperage is electrical "pressure"...back to highschool for him! What is your take on his capacitor arguement? Thanks for your time. Andy he's obviously not too bright or he failed to pay attention in his circuits class-------i really hate arguing with idiots on the internet-------it really gets old after about two paragraphs.............RRC __________________ Richard Clark at AMI |
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#22 (permalink) |
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Member
Join Date: Dec 2006
Posts: 97
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DONE.........
Lets talk fun stuff now |
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#23 (permalink) | |
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Senior Member
Join Date: Mar 2006
Location: California
Posts: 1,782
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When you're done making lame attempts at insulting me, you can go ahead and post up some evidence to back up your capacitor nonsense. Here, let me RE-POST mine:
http://en.wikipedia.org/wiki/Car_audio Quote:
Now let me explain the hose analogy again. The voltage would be the diameter of the house, and the Amperage would be how quickly the water flows out of that hose. The actual amount of total water can represent wattage. Say you need 1 gallon per minute of water, and you have two hoses, one that is 1/2 inch in diameter (DC power) and one that is 10 inches in diameter. (AC power) The 1/2 inch hose is going to need to flow very fast to get the gallon out in a minute. It needs a lot of "current" That ten inch diameter hose on the other hand isn't going to need to flow very fast to meet those requirements, So it doesn't need as much "current," to put out the same gallon of water
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Last edited by Codiddy : 05-21-2008 at 03:05 PM. |
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