Static in captured audio?

[JamesB69]

I have been capturing stuff and there is often static in the sound whether using the TV tuner or the RCA inputs.

I have the sound running from my Leadteak Winfast2000 Expert card internally to the Aux input on my Audigy 2 ZS. The only time there is static is when a scene gets loud (usually involving loud bass). I tried capturing with both PCM and compressed formats with the same thing, what gives?

[Soopafresh]

Sounds like digital overload of your inputs. Your source is too hot. Either reduce the sensitivity of your mic input on your sound card, or plug into your line in to record. Lastly, you can get an attentuating patch cord from the Radio Shack for less than $10 and that will do the trick as well.

[JamesB69]

aha, that makes sense... (BTW, it is plugged into AUX, which is like a line-in, not a mic)

anyways, i had recording at 100% (+6db) and it can go all the way down to -48db...

what level should I choose? is there a standard setting that should yield "normal" recording levels?

[anubis13]

Find a fairly loud section. play it back and use the meter of your recording app to see how hot the signal is. Then pull back on your input fader until its -4 to -10 dB from clipping. that will be your recording level

[JamesB69]

It has a meter that goes green, then yellow, the red...

Do I need to stay out of the yellow or out of the red???

I lowered it down to 50%(0db) and it stays a little below the yellow, and it seems to peak into the yellow during loud parts, but is still a decent ways away from the red...

[Soopafresh]

In the days of cassette decks, it used to be OK if the meter would peak every now and again into the red while recording, just as long as it didn't stay in the red. With digital recording, that results in some really horrible sound.

Yellow is OK, it's when it goes red that you're in danger of digital overload.

You ultimately want it loud enough that you don't get hum and hiss, and soft enough that you don't overload. Play with the levels and try her out.

[dphirschler]

You ultimately want it loud enough that you don't get hum and hiss, and soft enough that you don't overload. Play with the levels and try her out.

Hum would most likely be from a bad ground. I suppose you could also get it from feedback.

Hiss would only occur if recording to cassette. All cassettes have a noise "ceiling". In other words, they all have hiss even when playing a silent part. Your aim is to set recording level as close to the ceiling as possible. That way your recording will be nice and loud and you won't have to turn it up to hear it, which would in turn also amplify the hiss.

But this is the PC and you are recording digitally. So you don't have a noise ceiling. Hiss in that respect won't be a problem. But you do want to make use of all the available bits (16) so that you take as accurate a sample as possible. So you now have a new reason to get as close to the ceiling as possible, only now it is a clipping ceiling, not a noise ceiling.

And hiss can still be a problem if your sound card isn't designed with proper sheilding. Noise from the PC fans can cause audible interference which manifests itself as hiss. Also, the sound card itself can introduce hiss.

Finally, there is little you can do if your source recording has hiss. You have to capture it as it is. However, you can try to reduce it with digital filters afterwards.


Darryl

[Ron B]

I know this sounds over simplified, but if you have noise though all your efforts, check your cables. Bad cables cause a lot of problems. Even a bit of corrosion or oxidation on your connections can cause static.