top!

 

I recieved a SubSolutions subwoofer box for chirstmas, I took out the plastic thing from behind the seats, and the box fits perfectly, I have yet to hear it, it has two 8" speakers inside. Designed very well, color is almost perfect to the interior of the truck. Also needed was a 250 watt amplifier which will be placed underneath my seat, and a "converter" for the stock deck. The converter taps into the outgoing signal to the rear speakers and feeds a very small portion of it to the amplifier. Most after market audio deckks have this built-in, and most factory decks do not, since they usually produce enough power to supply the speakers with. It would be unwise to install the proper amp-outs when the majority of car buyers do not upgrade their audio systems. After market audio systems (decks), however, tend to appeal to the crowd that has more in mind than just a deck upgrade, which would most likely include an amplifier. This is why after market decks come with amp-outs. The reason why I have not heard the system was because the company I purchased the system from had just ran out of the converters, and they would be in the following week. Two months later they called and saidd they just cam in. Planning ahead, I completed the installation of the subwoofer and amplifier, making the proper connections to the battery and an extra thick wire for the ground. The ground wire is the most important part of the system. The importance of the ground wire is like that of the driveshaft. If it is too small, or too long, the power generated by the motor (amp) would snap the driveshaft (ground wire). If the ground wire is a little too small, or in the wrong place, electricity has a funny way of messing with other parts of the rest of the electronics that are tied into the same ground. This could lead to a variety of electrical problems, which may include burning your alternator.

The alternator is another factor one must include when upgrading the audio system, I have chosen not to severely upgrade my system, with only peak demands of 250 watts, and max continuous power of 160 watts (from amp). I will only utilize approx. 100 watts at most as this is a small cab. Most stock alternators usually generate 23-28 (I forgot the specs) amps, given todays cars are 12 volt systems, that would equate to approx 270 - 336 watts of power. Keep in mind not only must this alternator power your audio system, but it also must power your headlights, instrument panel, ignition system, it all adds up. I beleive it equates to approx 16 amps used at all times. This means 7 - 12 amps are available for use without demanding too much power from the alternator. In my case I will probably have a demand load of about 8.3 amps every weekend. This puts me in a safe range. Ever look at the alternator in these things? Pretty hard to get to. If you really want to upgrade your audio system, I suggest you get your favorite alternator catalogue and order a $5 part that allows your alternator to let out more power, once again I forgot what part in the alternator limits the output, but it can be changed without purchasing a whole new alternator, similar to the speedo gears on the old trannies when different size tires are added. It is a small part, yet important if you are severly upgrading your audio system, or if you decide to add a bunch of lights to your truck. I know it was overkill, and I am no electrician, but my mothers boyfriend is in a union and they sent him to an auto class. About the same time I was looking into this audio system, he was learning about auto electrical systems. I just thought I would let everyone know how I wasted my time writing all this when I should be studying for chemistry! I hope it helps.
Thanks for reading.

PS here is a cost chart
Subwoofer $450
Amplifier $189
Install kit $60 (recommended)
Converter $50 I suggest a high quality converter, lower quality converters let you hear the engine rpms through the speakers. This was the one the sound dude recommended for me.
Total cost $750, he offered installation for $119, and I would have jumped at it, but I am paranoid about someone else's fingerprints and farts on my Lightning. I know I am getting tired. Good luck, I hope it helps.

------------------
99 Black Lightning
created 8/17/99, bought 9/25/99
#3681/4000
CD changer, Tow package, factory tonneau cover
100k mile warrantee, bed/under liner, paint protected

 

I have to say that I think you guys that are buying those $50 "speaker output to preamp converters" are throwing your money away. Allow me to explain (this will require a brief electronics lecture). Most aftermarket decks put out between 40-45 watts of peak power. Power=Voltage x Current, or Current(squared) x Resistance. Volage=Current x Resistance. Using those formulas, you can conclude that most decks put out between 12.5 and 13.3 volts. Most aftermarket amps will accept "preamp" signals of up to 6.5 volts (some up to 8). Also, most amps have an input resistance of 10,000 ohms. When resisters are wired in series (like two speakers) the voltage is divided between them. If the resistors are the same value, each gets half the total voltage being put into them. So, if your deck puts out 13 volts, and you wire a 10k ohm (10,000 ohm) resistor in series with the speaker output, into the external amps signal input, your amp will see a 6.5 volt preamp signal (assuming your amp has an input resistance of 10k ohms. Check with the manufacturer to find out.). Instead of buying a preamp converter for $30-50, you did the same thing with two 20 cent resistors (one is needed on each channel, on the positive side.).

Hope I've saved some people some time and money. Feel free to e-mail me if you have any electronics/stereo questions or just questions in general.

Brett

lilbeam@hotmail.com

 

LilBeam, I didn't check the math, but it looks right. Although this would work, you failed to take into account the EM Noise in a vehicle, which is substanial. By doing this, you will basically have an antenna for EM noise that will be amplified (in the amp) and reproduced by your speakers, not good.
The Speaker level to RCA converter will eliminate this because the antenna will be short (<2") and the RCA are shielded.

 

Umm, How about you just follow my initial instructions and move the fade forwards a little

Just teasing guys, but I've enjoyed hearing you all chit chat on these tangents.

 

200Silverbullet,

Please elaborate on what you mean by creating an antenna for the EM noise in a vehicle.
Also, I will say that I was only 75% correct in my original post. My math was right, but my method was slightly off. I'm working out the details with my electronics instructor, because he said there was a better way. So far he said a voltage divider would be needed instead of what I originally said. A voltage divider would simply use two resistors instead of one per channel. I'll be talking to him on Wednesday (3-15-00), so I'll post a brief description of the changes then.