amp question

[meef]

ive got a 98 ESi...was wondering how everyone ran their wires from the trunk to the battery? i mean thru the car some way or another, but how did yall do it? or have it done?

 

[TwinkY]

a good way we did on my friends celica was run it under the bottom door panel (not the panel but the thing that is under the door when u open it) it should b put on with about 3 screws? and just put the wire under the door and run it to the dash. i will take about an hour er so

 

[meef]

hm...could you elaborate a lil more? i understand what ya mean by the door thingy...but whered you start at?

 

[siueclipse]

cut a hole in the firewall, ran wire to center console and back under the console, under the carpet and under the rear seats to where the spare is stored.

 

[TwinkY]

you could also do that... well it all depends on where ur amp is on the box and everything

 

[meef]

hm...if i put the amp under my seat, how hard is it to get under the carpet to run it in both directions? i mean i can run the one to the battery thru the console, but what about the back? how hard is that to get under the carpet?

 

[4g63tc]

the eclipse/talon has a wiring channel on both sides of the car. Look under the sill panels in the door underneath the carpet. for a hole in the firewall just look for an unused rubber grommit, and go through that.( i found one underneath the glovebox.)

same place i ran my n2o lines.

 

[meef]

tight....thanx fellas. take it easy..ill let ya know how it goes once its done..

 

[ENEVEL RACER]

Make sure that you don't run the RCA cables along with the power line or next to any other high power source. A high power source can disrupt the signal traveling through the RCA cables.

 

[xplosivetalon]

yea i got a 95 talon and i used to work at beam riders a car audio place in bc..neways best way to do it is run ur power wire down the passenger side and ur rca's down the driver side along with ur remote wire. i say this becuz in order to get thru your fire wall you will need get under behind the glove department area. u will see the rubber gramet people have been talking about earlier. Just slide ur power wire thru there and hook it up to your battery ( remem to use a fuse ). so basically start from the battery and then thru the firewall and to ur amp ( of course hiding the wires as mentioned above thru wiring channels on the driver and passenger sides
-good luck

 

[meef]

thanks a Ton everybody...beats the hell out of payin like $100 for the install...not counting the wiring...

 

[greyforestgst]

weird, i have my rcas and power wire running right next to each other down the wire tray under the door and i dont have any problem...

oh, and the steering column boot is an extremely easy place to run your wires from the cabin to the engine bay.

 

[ENEVEL RACER]

Originally posted by greyforestgst
weird, i have my rcas and power wire running right next to each other down the wire tray under the door and i dont have any problem...

oh, and the steering column boot is an extremely easy place to run your wires from the cabin to the engine bay.

You may have shielded RCA cables, which are about twice the price of basic RCA cables. The reason they recomend running them seperate is that the RCA cables are sending iformation to your amp at around 5 watts, and everybody knows that the longer the cable, the more wattage you lose, so any high power lines running along side of it could disrupt the signal, or you may just get a whinning noise at low volume. Usually it can be heard if your stereo is on, but the volume is all the way down, then rev your motor a couple of times, if you can hear the motor reving through the speakers or a whinning noise that changes with the rev of your motor, you have interference. That's why the came out with RCA's for car stereo's, cause high power speaker lines directly connected to the amp almost always give you that problem.

 

[scorpion]

The way I did mine was I removed the battery, under the tray there is a bundle of wires already going though the firewall. I ran the amp wire though that and then into the track under the passenger side scuff plate. On the drivers side there where already a ton of wires in there so it was easier on the passenger side. Also if you don't want to hear the whine from the alternator, make sure you ground your amp well and that the ground wire is as short as possible. Run the RCA cables and remote turn on lead under the center counsel, and under the rear seats, this will keep then seperated and easy to run.

 

[steve]

Originally posted by ENEVEL RACER
The reason they recomend running them seperate is that the RCA cables are sending iformation to your amp at around 5 watts, and everybody knows that the longer the cable, the more wattage you lose, so any high power lines running along side of it could disrupt the signal, or you may just get a whinning noise at low volume. ... That's why the came out with RCA's for car stereo's, cause high power speaker lines directly connected to the amp almost always give you that problem.

I really pondered responding to this but I couldn't let it go.

RCA style signal cables have been around for decades. When car audio started they used the same interconnect stardard as used in home audio for years and that turned out to be both useful and unfortunate. The standard was 1v p-p into 10k impedance unbalanced (signal referenced to ground). So an amp would produce it's full rated output with an input of 1v. This works just fine at home but in a car there are lots of noise sources and the unbalanced signal cables are more likely to pick up that noise than say balanced cables. In a given environment the signal level created by noise is constant. With a 1v p-p input a few milivolts of noise is very audible. One way to solve the problem is improved shielding on the interconnects, another is to increase the level of the drive (input to the amp). When you go from a 1v p-p to a 5v p-p the the relative noise level drops 5x. It's still the same noise imposed on the cables but it's a smaller percentage of the input signal so the noise margin inproves.

That said the problem I had with your post was that there is nothing close to 5W used in the interconnects in a normal system. Power = Volts^2 / Ohms. Ignoring conversions to RMS, 1v^2 / 10000 = .0001W or 5v^2 / 10000 = .0025W. At these power levels and a 10k input impedance the resistance of the interconnect isn't a real factor. The issue with longer cables is the longer the cable the more likely it is to pick up noise. Since all wires carrying current create a electric field directly related to the current and wires in a changing electric field will induce a voltage in that wire, putting your interconnect near the speaker wires or power cables can create noise on your input. That noise is always there but as you turn the volume up it's a smaller part of the whole signal and less audible and now we are back to rasing the input voltage lowers the noise levels due to less gain at the amp.

Steve

 

[ENEVEL RACER]

Originally posted by steve
I really pondered responding to this but I couldn't let it go.

RCA style signal cables have been around for decades. When car audio started they used the same interconnect stardard as used in home audio for years and that turned out to be both useful and unfortunate. The standard was 1v p-p into 10k impedance unbalanced (signal referenced to ground). So an amp would produce it's full rated output with an input of 1v. This works just fine at home but in a car there are lots of noise sources and the unbalanced signal cables are more likely to pick up that noise than say balanced cables. In a given environment the signal level created by noise is constant. With a 1v p-p input a few milivolts of noise is very audible. One way to solve the problem is improved shielding on the interconnects, another is to increase the level of the drive (input to the amp). When you go from a 1v p-p to a 5v p-p the the relative noise level drops 5x. It's still the same noise imposed on the cables but it's a smaller percentage of the input signal so the noise margin inproves.

That said the problem I had with your post was that there is nothing close to 5W used in the interconnects in a normal system. Power = Volts^2 / Ohms. Ignoring conversions to RMS, 1v^2 / 10000 = .0001W or 5v^2 / 10000 = .0025W. At these power levels and a 10k input impedance the resistance of the interconnect isn't a real factor. The issue with longer cables is the longer the cable the more likely it is to pick up noise. Since all wires carrying current create a electric field directly related to the current and wires in a changing electric field will induce a voltage in that wire, putting your interconnect near the speaker wires or power cables can create noise on your input. That noise is always there but as you turn the volume up it's a smaller part of the whole signal and less audible and now we are back to rasing the input voltage lowers the noise levels due to less gain at the amp.

Steve

Sorry, I didn't mean 5 watt, I meant 5 Volt. I'm a CAD drafter for a state public power facility, and sometimes type faster than I can think, your are right, it's Volts not watts. But the matter of fact is that a low voltage like that can be diminshed on longer cables since they don't use much wire to support the current. That's why monster cable came out with thicker shielded RCA's. Frankly, I've never had a problem running unshielded RCA's, I just keep them away from power sources, and never get a whine or hum. But thanks for the info.