12V vs 13.7V For Car Audio Components

[enskpo]

Does it make a difference?  My alpine car amp sticker says it's rated at 14.4 volts, will it perform as well at 12 volts from my computer power supply?

[richms]

No, not as well as at 14.4v

Will it make any difference in a mame cab - probably not.

If the PSU is dedicated to the amp you can open it and turn the voltage up with the trim control, but they seem to max out at about 12.8 or so.

makes a big difference to a car fridge tho.

[Blanka]

Amps mostly handle well in a range +/- 20% of the nominal voltage. If there is a controller/pre-amp IC in the amp that needs 5 volts, it mostly has its own voltage regulator. For the end-stage, a difference in voltage only affects maximum output power, and since dB logarithmic is applied, it never means more than 2-3dB difference in output levels.

[enskpo]

Great- thanks for the input- it looks like I'll be OK.  I'll have plenty of wattage to compensate for any lost volume due to lower line voltage.    I was more concerned with the sound quality instead of decibel output.

I had to decide whether or not I'm going to return the 13.7 volt, 25 amp Radio Shack power supply now that I've just received the Corsair TX750 computer power supply (or return the Radio Shack and get a better 13.7 volt power supply for cheaper; after my teachings here )

[rovingmind]

Your car alternator puts out 13.7 volts on average to run your vehicle and charge the battery. 

As for sound quality.  In the morning when the surface charge wears off and your battery is sitting at its rated 12 volts turn on the radio and listen to it at normal volume before you start your car.  Then turn the car on and listen to it again at the same volume.

 See how much of a difference you hear.  The human ear can detect a difference of 3 decibels.  Just make sure your 12 volt power supply can supply enough current to feed the amplifier you choose.

[heffe2001]

FWIW, I've had 0 problems out of my Corsair TX750 running my amp, and it will get much louder than you can stand without having any issues at all (it's not shut down once, nor failed in any way at all).  With the tolerances on most amps (roughly 20% on the input power), you can power them down to about 10.7ish volts and it'll still work (although you'll be outputting less power at that voltage), so the 12v supply on that Corsair will be fine (and it'll push 60a down that same 12v line, so you'll be hard pressed to overload it with a single amplifier).

Great- thanks for the input- it looks like I'll be OK.  I'll have plenty of wattage to compensate for any lost volume due to lower line voltage.    I was more concerned with the sound quality instead of decibel output.

I had to decide whether or not I'm going to return the 13.7 volt, 25 amp Radio Shack power supply now that I've just received the Corsair TX750 computer power supply (or return the Radio Shack and get a better 13.7 volt power supply for cheaper; after my teachings here )