{"id":4660,"date":"2019-06-20T12:24:28","date_gmt":"2019-06-20T17:24:28","guid":{"rendered":"http:\/\/baselines.com\/?p=4660"},"modified":"2019-06-20T12:28:11","modified_gmt":"2019-06-20T17:28:11","slug":"was-this-a-differentiation-operation","status":"publish","type":"post","link":"https:\/\/baselines.com\/?p=4660","title":{"rendered":"DC Level on an Audio Signal"},"content":{"rendered":"\n

I found this fascinating, but I don’t know everything in detail. Here’s what I just did.<\/p>\n\n\n\n

I downloaded a music track of a guitar playing from Bandlab. When I imported into my DAW, I noticed that the waveform was not centered. It appeared to be above the mid-line, leading me to think there was a DC component. It was present through the whole track.<\/p>\n\n\n\n

I exported it from the DAW and then reimported it as an additional track. It was centered. It looks like the DAW export might have done some processing.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The differences brought me back to my EE days. The top image with the ‘DC’ component shows a step function. The image in the bottom has eliminated that DC component. Looking at the point where the step was, it looks like a little pulse remains, with some ringing afterwards.<\/p>\n\n\n\n

I noticed in my DAW, I did have some other processing going on. By process of elimination, I found out that the ‘console emulator’ was what had cleaned up the signal. Here is a link to more information about the console emulator. https:\/\/www.cakewalk.com\/Documentation?product=SONAR%20X2&language=3&help=ProChannel.8.html<\/a><\/p>\n\n\n\n

With only the console emulator in the processing path, here is what the difference looks like on the stereo signal.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

It looks like another component added some additional processing in the first image because there appears to be more of the ‘ringing’ activity after the pulse.<\/p>\n\n\n\n

I guess the takeaway is that the console emulator, which I usually have on each track, contains some sort of brick wall high pass activity, and will remove the DC component for you.<\/p>\n\n\n\n

<\/p>\n\n