Pre Output Voltage, Before Clipping

Pre Output Voltage (Before Clipping) : 2 Volts

can someone explain that to me?

This is important. Good to ask about this topic.

Basically your h.u will output a voltage in its pre amp signal (usually the rca cables). This voltage varies from deck to deck. It is important and usually good to have higher pre-outs, but there are OTHER variables to it as well.

So to answer your question now, that statement you have there claims that the h.u will produce 2 volts of output to your amplifier. It may produce more, but like a gain on an amp, if pushed too far it will clip and send a "square" signal. This will cause your amp to clip (bad).

If you are still unsure, there is some more technical info here.  http://www.bcae1.com/preoutv.htm  

Preout voltage is the voltage (measured in AC) put out to the RCA's.  If you were to view this signal on an o-scope, it would look something like a sine wave- a "squiggly line".  When the volume is turned up too high, the peak-to-peak voltage cannot be increased (due to the components limitations), so the tops and bottoms of the signal is "clipped off".  Viewed on an o-scope, the tops and bottoms would be flat across.

I tried to find a visual on www.bcae1.com to help better, but couldn't.  Maybe someone else knows where one is.

would a line driver help then?  line driver meaning up my preamp voltage to 4volts? 

good website though dwarren. somewhat to complicated for me.

Line drivers often create more problems than do good. Yes they bump up voltage, but they often introduce noise into your system. They must be installed as to the h.u as possible. Most line drivers are cheap and poorly designed.

A low pre amp voltage isn't necessarily bad, the actual cleanliness of the signal is more important.

geepherder, i can visually see what your are trying to explain about the tops and bottoms being flat.. but what happens when that happens though..

It sounds like garbage.