Correcting wave shift up/down?

I have a problem when I record from tape to my PC using Audacity the resulting waves/sound is shifted down, so the centre of the wave (in height) is slightly below the 0.0 line (or the silence in a track is below the 0.0 line). I found that using the effect “Sliding Time Scale/Pitch Shift” with default values fixes this, but is this the right way to fix it. I just wondered if there are any adverse effects to using this to shift the whole wave up.

I tried searching for information but I’m not sure what the problem is called so all I got what information relating to moving and syncing audio tracks.

You have what is known as “DC offset”. This is most likely to be down to a fault with your souncard.

You can use Audacity to correct this though. Immediately after capture, select the whole project and then click Effect > Normalize

Just check on the box that says “Remove ant DC offset …” and make sure that the “Normalize …” box is unchecked (as you don’t want apply any amplification at this stage, just remove the DC).


Thank you for your quick reply, your solution works perfectly.