Yes- Overall, the higher the voltage of the preouts, the less chance that something will make the audio distorted- Eclipse is even rumored(I have only heard of them, not seen them) to have made some headunits with 18 volt preouts for competition use.
18v is rediculous.. why pay that much when you can take high ouput and plug it into the low level..yeah, yeah I know its not recommended.. but it will make that amp sweat when your volume is only on 1! 8v is more than enough in the industry.infact I beleive the 8V is intended to be split between multiple amps so theres enough juice in running to multiple amps... and to think my .2mV carpc on a JL Audio amp hurts my ears..lmao..
Did it.. Done it... now I got to keep the neighbors kids away!!