View Full Version : Preout Volatge
04-17-2010, 07:03 AM
First in foremost, i know it's a noob question.
but here we go!
Preout voltage on a deck... what does this actually do?
My pioneer avic-d3 has 2.2 volts...
I see some eclipse decks have higher preout volts...like 4volts or so...
if my avic d3 had 4 volts instead of 2.2 with the exact set up right now, would it sound any different?
04-17-2010, 12:29 PM
basically you match you amps to your head unit
2.2 vs 4 volt...4 volts = you dont have to turn your amps gain up as much, which means the CHANCE for less noise.
its more marketing than anything.
04-17-2010, 10:12 PM
Some decks are rated at 4v but when you actually take a oscilloscope you'll often find it to be less than that, rated and real world performance is almost always different.
I have no trouble driving three amps to max output with my current cheap *** Pioneer deck that only has 2v preouts. Noise? Never encountered them.
Don't go cheap on the interconnects, get "twisted pair" RCA cables with OFC copper for wires.
04-28-2010, 10:24 PM
Your amp gain setting will make 2 V or 4 V or whatever be exactly the same V as what the amp wants to see at it's primary amplification stage assuming you set the gain correctly.
Assuming the presence of low V noise in your system from electronic ignition, alternator fans etc..,
The difference is that with the higher starting V you've got twice as much headroom (on paper) over the noise threshold. Since the noise is amplified along with the signal you have just increased your signal to noise ratio in your primary amplification stage.
a 2 V system will amplify the noise to double the level of a 4 V system at the amp gain stage of adjustment.
Of course in real practice both versions can be just as perceptably quiet because the noise level is likely still very low compared to the signal level and the noise picked up in your signal line can be picked up in your amps as well, so, yea it helps and it's better, but I wouldn't trade out a 2V HU because it had lower V pre-outs.