Been looking into and studying "Line Drivers" Do I want one? To my knowledge they take the voltage from the HU and amplify it, then send it to my Amplifier, allowing it to perform "better?" I have an Alpine IVA-D310 and to my knowledge it only does 2v. I see these Line drivers.. have the capability of turning it into or up to 5 sometimes more V. Any input would be helpful, Feel free to help Glass.
Well, here's the problem with a line driver. Garbage in = garbage out. By this, I mean if our head unit puts out 2 volts, then a line driver will only amplify the 2V signal. That's the same thing the amplifier you're connecting the head unit to does with it's input stage anyway when the gain is set properly. If there is any noise floor in your head unit's output, then the line driver will amplify that noise along with the signal itself (s/n ratio here makes a difference)
The only time a line driver is really helpful is if the signal voltage isn't strong enough to reach the amplifier cleanly otherwise, which in a 20 foot run, is never going to be an issue. 200 feet? maybe.
In short, I wouldn't really bother with one. Go straight from source to signal processor or amplifier(s) and set the gains right. if the input stage matches the output stage voltage, you'll have the cleanest signal possible. keep it simple. the fewer things there are in teh system, the cleaner and mroe accurately the source signal will be reproduced.
This is why home, pro, and some high end car audio systems use XLR, optical, or other balanced or digital means of signal transport. To preserve the source signal as much as possible.
Think of a line driver like magnifying a JPG image. The more you blow it up, the more distorted and pixelated it becomes.
electronic crossovers are very useful, but most head units now offer 3 pre-outs and a built in crossover, so an external one isn't required. The amplifiers often have HPF or LPF onboard as well, although try not to use both the head unit and amplifier crossovers at the same time. you'll run into issues like the crossover slope from both XOs being cumulative.