View Full Version : Deck noise...how to tell?

12-16-2006, 09:06 PM
I want to know, is there something in the specifications of a head unit that would allow you to know whether or not a deck has high or low amounts of 'white noise', or the noise you get when the HU is on, but not playing.

This is assuming that the rest of your car has 0 interference. I'm looking for the noise created by the deck itself. The issue is that when you start amping it, I'm worried about the deck sending a noticeable amount of this noise through the amp at higher levels.

I know amp quality, gains, etc.. also has an effect on this.

Is the S/N ratio what I am looking for? If it is what is better, high number or lower number?

Thanks for your help

12-16-2006, 10:18 PM

12-16-2006, 10:36 PM
Well its hard to tell what noise is caused by the deck itself. Because if you hear noise then it could be the amp that is pushing the speakers. The best thing to do is find a test CD and listen to track labeled "digital silence" or something close to that. Fact is, this test will only tell you how noisey your AMPS are and not the deck.

12-16-2006, 11:33 PM
Ok, well then, what is the way to tell if an amp will have the noise by looking at a spec sheet?

I'd imagine S/N (otherwise called noise) would be the obvious thing, But is a higher S/N number better or worse?

12-17-2006, 03:55 AM
Well, for starters the HIGHER the signal to noise ratio the better....measured in decibels.

However, system noise doesn't always have to mean you're screwed. And a high S/N ratio doesn't always mean you're home free either.

A couple of questions for you for starters.

1 - How old are your amps and what quality are they.??

If they are fairly new (less than 5 -7 years old) and of good quality (as in they aren't LOW budget amps found at a flea market or a discount website and brand name is something you've never heard of) then they will most likely be pretty clean. However if you're running a deck with very LOW voltage preouts then you would have to turn the gains up on those amps when you set them and this could raise your noise floor up and you would hear the HISSING sound known as noise.

2 - As stated in the last paragraph, how high is the voltage of this deck's preouts??

A deck with a rated 4 volts or higher will most likely let you set the gains on your amp(s) lower and therefore lessening the chances of system noise.

So in short, I wouldn't worry too much about your deck inducing noise into your system as long as the preout voltage is sufficient. And for the amps to be that loud they would have to be pretty OLD or POOR QUALITY.

12-17-2006, 07:31 PM
Nice, thanks alot!

I forgot all about higher pre-outs being better.