Linear Scale Recording Line not on Zero.

Can Any body please help. For a while now the Linear scale recording line is not set on 0.0 but on 0.3 and sometimes on to 0.4 but never 0.0. The only time the recording line is align with the 0.0 linear scare line is when i put in a fade in or fade out effect on it. I have put two snap shots to show what i mean. If any one can help me that would be great. Thank you.

The problem is called “DC offset”. It is one of the most common hardware faults of cheap / on-board sound cards. There are also other possible causes, such as if you are recording from a fault device that puts a DC voltage on the input. We have also seen at least one case where it was due to a sound card driver bug. Yes it is a fault and yes it needs to be fixed, so the first thing we need to do is to try and find where the problem is coming from. Please describe the equipment you are using and what / how you are recording.

So for the late reply. I usually record from a Yamaha EMX 5014c powered mixer but when I recorded the snap shots I recorded with nothing in the mic jack port. Also my notebook is a Toshiba Satellite A200.

So you are saying that the images are from when you were recoding using the built in microphone?
Does the problem also occur when you record from the Yamaha EMX 5014c?
When recording from the Yamaha, how is it connected to your computer?

From the yamaha mixer aux 1 output into standard mic port in notebook. I can remember that the problem occurred on my old laptop (dell) about a 6-8 months ago. When I changed laptops I made a new audacity download and as I’ve aready said that the problem remained. Also I’m recording in mono and I’ve tried stereo aswell with same results.

It is probably a hardware or design fault with the built-in sound card, or possibly a fault with the sound card drivers. If you look in the Windows Sound Control Panel there may be an option to remove DC offset. Removing DC offset is only a partial solution because although it will centre the waveform in the Audacity track the waveform will probably clip (distort) prematurely. If your sound card does not have that option, then you can use DC offset correction in the Audacity Normalize effect ( but please note that (like the Control Panel option) this only repairs the symptom, it does not fix the underlying problem.

Built in sound cards are generally designed to be adequate for Skype and similar applications. They are not designed for high quality recording and so consequently it is very common for the recording quality to be #&*@! A cheap and effective solution is to use a USB sound card that has stereo line level inputs (such as the Behringer UCA 202 - about $30).

I’ve looked in sound control panel and could not find the Enhancements option. This Behringer UCA 202 device, are you saying that it will fix dc offset and/or kinda like bypass the sound card in a way? not sure how this device works. Sorry for my ignorance.

The Behringer UCA 202 is an external (USB) sound card.
In Audacity you can select which sound card to use for recording, and which one to use for playback via the settings in the device toolbar. When selected, the USB sound card can be used for playback and/or recording instead of the built-in sound card. I use a UCA 202 myself, and although it is relatively cheap and only in a plastic box, the recording sound quality is very much better that the built-in sound card on my laptop. (Playback quality is also very good, but you may find it more convenient to use the built in sound card for playback if the playback quality is OK).

One limitation of the Behringer UCA 202 is that it does not have a recording level control, but that does not matter if you are recording from a mixing desk because you can set the output level on the mixing desk so that the recording level is right (ideally about half the track height in Audacity).

Thank you so much for your help with this issue of mine. I think i will invest in the UCA 202. Thanks Again.