a few years ago i did an install in an EVO 8. it was a kicker L5 12 on some kind of mtx amp. The bass was ok but it didnt hit like we expected it to. So then I ran the RCAs from my head unit at the time (eclipse with 5v pre out) magically the sub came alive. (and yes the gains were set right for each application) so then we installed a JL audio line driver and upped the voltage on the guys head unit to ~6 volts. And it did the trick. Since then i have done many tests with and without line drivers and i swear it makes a difference and in some cases 1-3 db increases in spl. I know many people say its not possible or logical but i have experienced it first hand and im not a noob by any means. So my question is who uses them and how much of a difference did you see. Another comment i want to say is that most of the people who say you dont need one have never used one.
i use a soundstream 5x0 preamp on my set as a "line driver" , i keep its settings on flat & because of its 10v max output it makes a huge difference ...gain on both amps r on 0 ...
my eqs is an eq with linedriver, but i can't say that i've hooked up my sub without it bc it kinda runs my whole system. my system sounds fu<kin sweet though so i can't say anything bad about line drivers.
In all actuality if your amps gain is adjustable from .2 to 6V and your HU puts out somewhere in between if the gain is set correctly you should not notice a difference UNLESS you are overdriving the signal which indeed would cause signal clipping. There is no need for a line driver unless your input voltage is to low, signal processors are different. Polo..
I understand what you are saying Polo. in most cases where i am from people buy really cheap touch screen head units with low voltages. I think that it might have something to do with efficiency as far as the line driver goes. IMO if the signal is stronger then the amp doesn't have to work as hard to produce the same result. For instance a .2v signal vs a 5v signal. Because the amp doesn't have to work as hard it might be more efficient with its power output. i may be wrong but its a theory. in fact im probably wrong because i don't build amps
Polo is right on...... I will bet the people who say the line driver makes it louder haven't set their gains with a DMM..... b/c if they had there would be no difference.
so to sum the thread up there is no point to having a line driver because most aftermarket head units have enough pre out....thread ended. maybe these companies should stop production on them.