Whats the actual difference in pre out voltage

[itsblown 10+ year member]

So I realize that the pre out voltage is the voltage it sends through the RCA's and that having a higher voltage means more volts going through the RCA's and reaching the amp which means your amp has more to work with but Im just wondering how big of a deal that is as far as "loudness" gos

Im pretty much on my first system and the first thing I bought (before researching) was a sony head unit with .5v pre outs. Recently the left side RCA's seem to be dropping voltage. The entire left side of my car seems to be not as loud. If I go to my mono block amp and I remove the right RCA (which seems to be more powerfull) the subs will get really quite. the same goes for my speaker amp. the left side is quite enless i flip the RCA's around. So I figure my head unit is going. THis made me wonder if I switch from a .5v pre out head unit to lets say a 2v pre out head unit will my system get noticabbly louder. By the way im not talking numbers wise but will that be enough change for my to actually notice a difference.

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[PaulD 10+ year member]

as long as the HU output will drive your amp to full power, it makes NO difference. Higher voltage usually is less prone to induced noise and also means the amp gain can be turned down which generally means less hiss at higer volume (mid/tweet amps)

 

[CAT MAN 5,000+ posts]

cleaner/fuller signal.

 

[maylar 10+ year member]

cleaner/fuller signal.

Cleaner maybe, for the reasons stated above. But please define "fuller".

 

[CAT MAN 5,000+ posts]

Cleaner maybe, for the reasons stated above. But please define "fuller".

from my experience of going from 2v-5v on the 5v it seemed like the loud function was on if it makes any sense at all. i could hear a bit clearer etc. more sq oriented

 

[JimJ 5,000+ posts]

from my experience of going from 2v-5v on the 5v it seemed like the loud function was on if it makes any sense at all. i could hear a bit clearer etc. more sq oriented

This is the roots of a classic sales pitch for high-end audio. Just make whatever you want to sell louder, and people usually pick it as the one that sounds better.

Assuming there's no underlying noise problem, going to a higher pre-out voltage does absolutely nothing. Home audio unbalanced outputs very rarely have anything over 2V, and there's no issue driving amplifiers.

 

[IonRL205 10+ year member]

Never noticed any difference from using 2v pre outs or 4v pre outs.

 

[CAT MAN 5,000+ posts]

i dont doubt it. coulda been the headunit period. i believe you guys on it .

 

[trumpet 5,000+ posts]

I believe this is the same reason line drivers came into existance, because people started believing their head units weren't putting out enough voltage for their amplifiers to properly perform. People love seeing bigger numbers on a spec list when justifying their purchases, and 4V vs 2V is an easy one to do the math on.

 

[CAT MAN 5,000+ posts]

I believe this is the same reason line drivers came into existance, because people started believing their head units weren't putting out enough voltage for their amplifiers to properly perform. People love seeing bigger numbers on a spec list when justifying their purchases, and 4V vs 2V is an easy one to do the math on.

eh idk alot of hardcore sq guys still believe in it

 

[trumpet 5,000+ posts]

eh idk alot of hardcore sq guys still believe in it

I believe as you talk to people who are more "hardcore" or more to the purist audiophile end of the spectrum the amount of BS increases exponentially. See $2,000 6 ft speaker cables, cable supports to keep wires from touching the floor, etc.

The reason people will swear up and down they're hearing differences can sometimes be attributed to expectation bias and perception bias. Those biases affect all aspects of our lives as consumers. When a person wants to hear a positive difference they will hear positive changes. This applies even if they're getting a demo and there's no money on the table. Persuasion is very, very powerful.

 

[CAT MAN 5,000+ posts]

I believe as you talk to people who are more "hardcore" or more to the purist audiophile end of the spectrum the amount of BS increases exponentially. See $2,000 6 ft speaker cables, cable supports to keep wires from touching the floor, etc.

but they win sq trophies lol...

 

[trumpet 5,000+ posts]

but they win sq trophies lol...

Judges are people just like the competitors.

 

[CAT MAN 5,000+ posts]

touche....

 

[maylar 10+ year member]

I think there's some validity to the theory that if the source voltage is higher you need less gain at the amp and therefore attenuate any noise that might get picked up in the cables. Especially since you don't get the rated RCA level except with a 0 dB source and volume control at maximum. In my current install (allegedly 2.5 v) my sub amp gain is nearly all the way up. Luckily I use a LOC for the front stage and it has at least 4V out.

I think it's also true that 4V preouts come with more SQ oriented hu models.