Mixed messages
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Silver Member Username: ScubasteveAnnapolis, MD Post Number: 306 Registered: May-05 | "routing signal wires and power wires on the opposite side of a vehicle is a completely moot point" Is there truly no advantage in a well installed system of wiring the power wire away from the signal wire? I've always done it because I thought it was common knowledge, but is this indeed a myth? |
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Gold Member Username: IlluminatorPost Number: 1215 Registered: Apr-05 | I think it is. I've ran them together and couldn't get noise from the RCAs. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8740 Registered: Dec-03 | in 15 years as a professional installer, I've had to re-run plenty of signal lines away from power lines. It's mandated in the MECP guide as well, so yes I can tell you running signal and noise lines together <b>can>/b> cause noise. This doesn't mean it always will cause noise, but why take the chance only later to find out you have alternator whine in the speakers, and you have to pull the car apart again to re-do your work? |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8741 Registered: Dec-03 | signal and power lines away from each other that is. I just woke up. |
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Silver Member Username: ScubasteveAnnapolis, MD Post Number: 311 Registered: May-05 | thanks glass, thats basically what I thought, and I wouldn't have questioned it if it weren't written by scott buwalda who's aparently winning world championships. http://www.roadgearmag.com/article.asp?section_id=11&article_id=485&page_number= 1 |
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Gold Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 1471 Registered: Sep-04 | Richard Clark believes it to be a myth as well: You'll need to copy/paste that link to your address line. I think it probably depends on the situation. If a power wire already has a good deal of current passing through it at idle then I guess it would be possible for the induced noise to be audible at low volumes. -Fishy |
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Gold Member Username: InvainMichigan United States Post Number: 3329 Registered: Aug-04 | Glass you should take up Richard's $1000 challenge... |
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Gold Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 1472 Registered: Sep-04 | Just hook up a big inverter(1000-1500 watt) and run a hair dryer a la "P!mp My Ride". Might very well induce a thousand bucks worth of noise.  Five or six SS Class A 10.0's for subs would probably draw a good bit of current at idle as well. -Fishy |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8752 Registered: Dec-03 | why? I could just call Rich and tell him what I think.. lol I used to compete in the same classes as he did, years ago. anyway, a lot of this is going to depend on how well shielded your signal lines are as well. If you're using twisted pair or triple shielded lines, yeah most of them are noise cancelling or reject enough noise not to be an issue, but when you get a pinched cable that compromises the shielding, or you're using cheap cables to begin with (like a lot of people do.. think radio shack specials with no shielding to speak of) then you're going to run a much higher chance of having problems. I also stay away from high current power lines in the car itself when I can. Not just the ones I've run myself. Anyway, if you want to run them together, that's fine. I just don't see any advantage to doing it. If you run them together, you have a bigger clump of cables under the carpet and trim anyway. when I run big 0AWG cable the length of a car, I run it alone so I can put padding on each side of it under the carpet, so you don't see of feel a big pipe of cable running under your feet when you're in the car, too. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8753 Registered: Dec-03 | Rick has a point, but the problem is that older class A or class AB amps in particular draw a fair amount of current even at low volume or no volume, due to their power supplys needing it to keep the transistors operational with their bias current. The other problem you encounter is the signal lines being near things like ignition lines, and if you want to see a lot of voltage and a lot of current, see what your ignition system draws some time. Therea are, as Rick pointed out, real world factors to consider, and while taking the time to lay out a good wiring route is one way to help this, just as spending money on good noise canceling cables is, you have to ask how many people tear out the entire cabin of a car to build a stereo system, and how many just shove cables under plastic trim with a screwdriver, and do it themselves, cutting corners to get the job done in an afternoon before dad gets upset about it, or they have to be off to work.. and because they want instant gratification and want to hear the new system now! |
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Bronze Member Username: FandimReno, Nevada United State... Post Number: 68 Registered: Jun-05 | It really isnt an issue with subs, I thought? Just mainly amps for highs/mids? |
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