Head Unit Pre-amp volt....

[rn240sx]

I have a question regarding the pre-amp voltage from a head unit. I have 2 radio's here and one of them only runs a 2 volt output and the other runs a 4 volt output.What is the difference between the two other than 2 volts difference..??Why would one run double the voltage..?? Is there any benefit to it..?? Am i gonna physically hear the difference..??

ThanksRobert

[Rex]

From Carstereo's help pageQuote »RCA Outputs - If you are planning to run the speakers from the head unit's built-in amplifier, you don't have to worry about RCAs, but if you plan to add amplifiers in the future, get one with a set of RCAs (left and right), three sets preferably (left and right for front, rear and subwoofer). An important feature to look for is high-voltage RCA outputs. Typically RCA signals are less than 1 volt. High-voltage RCA signals are 2, 3 or even 4 volts. This allows for better noise immunity and gives you a higher headroom for amplifier gain settings. Most high-end manufacturers are selling units with high-voltage RCA outputs which are frequently used in competition.[/quote]

[IveBeenBad]

TO reiterate what Rex posted, the higher the voltage, the cleaner the signal which in turn gives you less distortion and less unwanted noise.

Also remember to run any signal and power wires seperately to avoid noise.

[DammitBobby]

I just replaced my old head unit with a Alpine pushing 4 volts to the amp. It sounds so much better!! My friend is a manager of stereo shop and he said Alpine is one of the better units.

[93sleeper]

It's all about signal-to-noise ratio when connecting the HU to the amp. Given that the voltage of the electrical noise in the wiring is a constant, you can get a huge benefit by increasing the voltage of the preamp outputs. So with 4 volts versus 2 volts, you should effectively hear half of the noise with the amplified 4-volt signal.

If you have really clean wiring without much ambient electrical noise you probably won't hear as much of a difference between the two. (Basically, if there were no noise at all...an impossible situation...both units should perform identically)

[Checkered-Member]

I just replaced my old head unit with a Alpine pushing 4 volts to the amp. It sounds so much better!! My friend is a manager of stereo shop and he said Alpine is one of the better units.

Alpine = Over Price and Overrated

my pioneer head unit (Organic Electroluminescent) is pumping 6 volts my amp gains are all the way down...and it costs half a similar alpine head unit

[DammitBobby]

This being the 3rd car I have replaced the head unit. All of them have been Alpine and not one of them have given me any problems. The unit I purchased was the lowest priced Alpine MP3 player and I only payed 239.00. I don`t think that is to overpriced. As far as sound quality I am very happy with it.

[Simmsled]

When it comes to the RCA preouts, voltage is important. One other variable that is important is the output impedance. This can range from 55ohms to a high number such as 10,000. For instance... Eclipse was the first company, back in the day, to introduce a low impedance high voltage RCA preout. Everyone wanted to run their decks because they were so noise free. If you have access to the output impedance level, check it out. If it is in the double digits, thats great, if it is more than triple digits, you might want to keep looking if you want the cleanest sound.