Up-Grade My Car Amplifier

[Dj BASS AMP]

Originally posted by millwood



better (or worse) in what regard?

you can always argue that 10000000F is better than 1F. but does it make a difference in real life? if not, why should we care?

i dont understand...!

what will be batter?

[Eva]

Equivalent energy storage placed after the power supply allways gives lower voltage drop to the amplifier circuit

Even if the 1F capacitor is showing .004 ohms at 60Hz, the power supply of a typical amplifier will apear as .030 ohms or so in series with the capacitor so the voltage drop inside the amplifier will be higher when energy storage is before power supply

Alternators operate as pulsed current sources whose amplitude is very slowly controlled by the regulator [amplitude depends on the magnetization of the rotor, whose inductance is huge], so the output impedance of an alternator is almost infinite at audio frequencies

Lead-acid batteries can only source some current when its cell voltage is made less than 2 to 2.1 volts, so when you put 20-50A of load to the 12V system, even if the multimeter measures more than 13 Volts, the instantaneous voltage will be oscilating between less than 12V between alternator pulses and 15V during the crest of the pulses

The only way to get DC voltages [not pulsed] higher than 12 V is to add some storage capacitance so alternator output could be truly rectified

An oscilloscope, a car and sompe patience will help to understand all these facts

Of course, don't expect car audio people to get an oscilloscope and have enough electronics knowledge to do some serious findings about this

Also, it's a very bad idea to have huge currents at 2*signal_freq flowing thorugh 5-10 meters of 12V supply wires because this produces huge magnetic fields and lots of magnetic induction on signal lines and speaker wires [the induced signal will be pure distortion due to its 2*F nature and can be measured with a simple loop of wire connected to the scope probe]

Again, don't ask car-audio people about magnetic fields or induction or about twisting 12V supply wires to reduce it

[Dj BASS AMP]

ok thanks u