now I see why I am Not seeing the watts that I fell I should. When I key my voltage goes from 14.45v to 10.5 to 11v does anyone have any Ideas on how to keep my voltage up when I key? I got two alts and a red top optima only seeing 700 to 750 out of 1x4 all 2879 fat boy. need cheap ideas like will a capacitor that people use for amps in car audio setups work? I see them at wallmart for like 30 bucks..... thanks
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now I see Voltage drop!
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Where do you measure the voltage?
At the amp with long wires connected, or at the battery when you key up?
At 11 volt and 750 watts out you need about 1250 watts in DC (60% effectivenesss), wich is about 113.6 Amp at 11 volts....
What amperage are the 2 alternators?, wired correctly?
If you have long wires on the amp and measure voltage tthere, you might need better cables to feed the amp.
At the amp with long wires connected, or at the battery when you key up?
At 11 volt and 750 watts out you need about 1250 watts in DC (60% effectivenesss), wich is about 113.6 Amp at 11 volts....
What amperage are the 2 alternators?, wired correctly?
If you have long wires on the amp and measure voltage tthere, you might need better cables to feed the amp.
You should be doing fine. Make sure the amp is powered by at least #4 wire, if it's along run go #2. How big are your alternators? Are they installed right? Were the charge lines off the alternators up-graded?
The Bat Cap thing is a point of debate. I say they don't work well with big cb amplifiers because you drain the thing in 2 seconds on a dead key. A car stereo has breif peaks from say a drum beat that let the Cap recover for the next spike. They do filter the power alittle though.
Something with you install or electrical system is not right, you should be fine with what you have.
The Bat Cap thing is a point of debate. I say they don't work well with big cb amplifiers because you drain the thing in 2 seconds on a dead key. A car stereo has breif peaks from say a drum beat that let the Cap recover for the next spike. They do filter the power alittle though.
Something with you install or electrical system is not right, you should be fine with what you have.
There are three possibilities here:
1. Your alternators are not installed correctly: Are they the same amperage rating? Are you sure both are charging the battery? Why do you need two alternators to charge one battery, anyway?
2. Your battery is insufficient to supply enough power to the amplifier for as long a period of time as you need it. Have your battery checked. Perhaps you should be using two batteries and one (beefier) alternator?
3. Your getting a lot of voltage drop from the battery to the amp. This is caused by using wire guage that is too small for the current required and the distant it's run.
BTW, 750 watts out of a 4-2sc2879 final stage of an amplifier is more than plenty. You're already driving the piss out of those transistors because the four are being driven by another 2sc2879. You can work on this problem all you want to get the wattage rating that you think you should, but your not going to be doing yourself or anybody else any favors by pushing that thing harder.
1. Your alternators are not installed correctly: Are they the same amperage rating? Are you sure both are charging the battery? Why do you need two alternators to charge one battery, anyway?
2. Your battery is insufficient to supply enough power to the amplifier for as long a period of time as you need it. Have your battery checked. Perhaps you should be using two batteries and one (beefier) alternator?
3. Your getting a lot of voltage drop from the battery to the amp. This is caused by using wire guage that is too small for the current required and the distant it's run.
BTW, 750 watts out of a 4-2sc2879 final stage of an amplifier is more than plenty. You're already driving the piss out of those transistors because the four are being driven by another 2sc2879. You can work on this problem all you want to get the wattage rating that you think you should, but your not going to be doing yourself or anybody else any favors by pushing that thing harder.
Before you go there check out ALL the connections at the battery posts and alternator connections as well as grounds. It could be as simple as a poor connection. When dealing with 100 amps or more it only takes a fraction of an ohm to drop a volt or two.If you were measuring directly on the battery posts and not on any connector then you may have a problem with the battery and/or charging system. BTW the wire should be larger than 8 ga. anyway.
The whole idea of Class C Competition amps is to push the limits well beyond what is technically clean and sane. That is their purpose. Irregardless of the way it's run, voltage drop is bad.
good comments here, cannot disagree.
If had 3 volts drop across a wire feeding an amplifier drawing 100 amps, that wire would be wasting 300 watts of power. That wire would be 0.03 ohms.
0.03ohms = 3volts / 100amps
300watts = 3volts * 100amps
You would have 3 volt drop if you had 14volts at the battery, and 11 volts at the amp.
This is why you need fat wires for amplifier running at automotive voltage.
If had 3 volts drop across a wire feeding an amplifier drawing 100 amps, that wire would be wasting 300 watts of power. That wire would be 0.03 ohms.
0.03ohms = 3volts / 100amps
300watts = 3volts * 100amps
You would have 3 volt drop if you had 14volts at the battery, and 11 volts at the amp.
This is why you need fat wires for amplifier running at automotive voltage.
ok easy fix I found 4 guage for $2.00/ft STUPID question If I upgrade the power wire do I have to upgrade the ground?
finally found 4 guage wire by the foot $2.00. If I upgrade the power wire do I Have to upgrade the ground?
B
BOOTY MONSTER
Guest
yes you need to upgrade both to 4 guage or higher .
dont forget to put a fuse on the 4 guage positive at the battery if you havnt already .
Parts Express:Wafer Fuse Holder
150 amp fuse should be fine . its to protect the vehicle from catching fire in case of a power line short . its NOT to protect the amp . the amp should have its own protective fuse .
dont forget to put a fuse on the 4 guage positive at the battery if you havnt already .
Parts Express:Wafer Fuse Holder
150 amp fuse should be fine . its to protect the vehicle from catching fire in case of a power line short . its NOT to protect the amp . the amp should have its own protective fuse .