My alpine head unit is only a 2 volt preamp output. If i bought a 5 volt preamp output, would it make that big of a difference? I know it will make a difference, but will it be significant enough to spend the money? Also what head units would u recommend?
you'll have a cleaner, higher resolution signal going to the amplifiers. that's the main difference. if you're running a pretty good setup with an amplifier on both subs and components, and you're setting up for sound quality, it's worth it. if you're only using an amp for subs, and you're not going to spend a lot on the rest of the system, I wouldn't bother. With properly set gain on the amplifier, you won't notice a big difference.