Help with my deck please!
 

Hey everyone,

I'm new on here but I love it, so I just have a question about volt pre-outs on head units. I was just given a new deck from my buddy, after helping him out with some stuff we figured this would be payment enough, so anyways he was saying that this deck (which is an eclipse deck) has a 5 volt sub woofer pre-out. He tried to explain it to me, but to be honest I was very confused... I was just wondering if anyone could clear this up for me. The deck I have now is a JVC arsenal and I love it, but it's a 2v pre-out, and I was told that this new deck would make my system louder, so I was wondering what all this means and if anything will it hurt my system? Thanks a lot in advance for the help.

Higher pre-out voltage does NOT equal a louder system. Your system will be as loud as your amps can make it. It does mean that you will need to turn the gains way down on your amp from where they are. I'll do my best to explain pre-out voltage.

Voltage levels indicate the strength of a signal that the HU sends to an amp. Your old deck produced 2v and your new deck produces 5v a substantial 150% increase. Which means that the amps will receive a louder signal from the RCAs. A louder signal at imput means the gains will need to be set much lower to acheive the same level of output. This however does mean that your amp will play louder. The physical limits of your amp cannot be altered by a greater input signal.

Think of it like the gas pedal in your car. If the pedal currently requires you to push it a full 6" to get maximum performance, you can adjust the pedal so you only have to push it 3" to get maximum performance. It may be nicer that way for performance so you don't have to push it as hard to floor it. But by adjusting the gas pedal settings won't actual alter the output of your engine - that is kind of how different input voltages work.

The benefit of a higher voltage pre out is that since your amp is receiving a strong signal, the noise floor will be lower so it will be a cleaner signal - less change for interferance to overpower the audio signal.

So in the end, your system will sound cleaner, not louder. If you neglect to adjust your gains, your amp will clip much sooner and your speakers will scream in pain.

Going from 2v on the sub out to 5v sub out means that your amp will be receiving a "stronger" signal from your headunit. This probably wont harm your amp in any way as most amps theses days handle up to 8 volt input signal. Basically running the higher input voltage will make the amp amplify a stronger signal, so you wont have to run the gain as high, or at the same gain it will be louder.

sorry, guess im a slow typer :)

Thanks!
 

Thanks a lot, that really helped and really made things clear, lol it actually makes a lot of sense now! Really appreciate the help!

Well ya it can handle 8v but my gains are way down as it is since my old sub (infinity reference 1230... whatever that thing is lol) would have been over powered by my amp, but I just picked up a type-r so I have to go get it wired up since it's DVC rather then my old single lol and then get the whole system tuned... so I'll just get it all together at once and properly lol. Thanks again you guys for the help and quick response!