Equalizer, line driver question?

I was looking on the internet at audio equipment and i ran across and equalize and line driver. I know kind of what an equalizer is but what is a line driver? Also do these items add a considerable ammount of sound quality to a system if used right?

a line driver boosts the signal in the output RCA's of the device considerably. It doesn't so much increase sound quality, but it can avoid some noise problems because the signal level is so high.

DING! Correct.

line drivers were invented because most of the head units only put out like 500 mV until like the 90's. It was causing a lot of stereos to be noisy no matter where they ran the RCA's. I have still have an old phoenix gold one, it had a receiver and tranmitter. The RCA's from the deck went into the tranmitter, it came out of the tranmitter at like 17 V RMS down a balanced line twisted pair cable to the receiver, then out of the receiver as RCA. NO WAY 17 V is gonna induce noise - even if you tie wrapped it to the power cable all the way down the side of the car.

so basically they use linedrivers to increase the volatge to the amp through the rca's. Well can amps take that much or is there a limit to the volts they can take. Also if the line driver is hooked up to an equalizer does that mean any thing or same thing onlt with and eq there too.

all audio control EQ's have line drivers built-in (that I know of) ....... it raises the signal level just before it leaves the EQ box.