WHY WE DON’T RECOMMEND HIGHER VOLTAGE
I guess I can list the benefits and drawbacks of running "higher voltage than normal" (I would consider above 15.0 "Higher Voltage"
1. Your batteries will top off faster. I say, "top off" because your alternator isn’t supposed to be a battery "charger" It’s meant to "top off" your battery after starting and run the electrical accessories on the car
2. Your amplifiers will make more power IF.... Your voltage is stable and DOESNT drop. You will need more alternator power than amplifier power for this to be relevant
3. Your headlights will be brighter. LOL
4. You will appear to be "cool" in all your YouTube videos where you show how pimp you are when your volt meter reads 15.0+ (yes, I was being sarcastic...)
5. Your alternator will make a few more amps at this voltage. (You’ll never know the difference though)
That’s about all the Benefits...Voltage is the illusion of having power
Why You Need Current Not Voltage
In car audio Current is power not Voltage. Voltage is the constant, not the variable. No matter how much power you have (wattage) voltage is always the constant.
When you buy a 1000 watt amp it's rated usually at 12.8 or 14.4 depending on if they go by battery voltage or alternator voltage for their specs. When you buy a 5000 watt amp it's the same voltage. It pulls more Current to make power.
When you buy a high amperage alternator you buy it for its amperage... Not it's voltage. When you buy that extra amperage that allows you to have less Voltage Drop. Voltage cant keep itself from dropping. If your voltage is dropping you can't simply raise the voltage..
You need more current in order to maintain voltage. Voltage drops because you don't have enough "CURRENT" .. Not because you don't have enough "VOLTAGE".