What Compressed vs Uncompressed LOOKS like

[Haoleb]

Well with all the talk of compression etc around here figured I would show a visual representation of a dynamic track and a compressed one. Some cool software came with my soundcard that allows me to look at audio files on sort of an oscilloscope representation. I can easily zoom in and see clipped waveforms and such with this software but this is a dramatic view of a dynamic track, "Up is Down" from Pirates of the carribean soundtrack (#3) and one of the most horribly compressed tracks I can think of taken right off of the red hot chili peppers perfectly produced "californication" *insert sarcasm here*

Without zooming in enough to see the actual waves you can easily see that there are peaks, and dips throughout the entire track.

If i were to zoom in on some of the waves in this tracks you would be able to see the clipped signal. As you can see its pretty much a solid block of noise for the duration of the entire track. Whoever decided to do this was certainly a genious because this could easily be a cd i would listen to all the time if it had some dynamic range and didnt sound like absolute rubbish. The vocal tracks are clipped!

 

[MDS]

You are showing the two tracks at different levels of magnification. One is 1:6168 and the other is 1:12217 and both of those are 'odd' zoom levels. The higher the zoom ratio, the more compressed things look which is not to say that the second track isn't more compressed than the other.

The first track obviously has a lower average level than the second but the second track may not be clipped. If you can zoom in to 1:1 and see little square waves then it is clipped. If there are multiple max-value samples in a row then it is clipped even if there are no visible square tops.

I have many tracks where the level meters hang around zero the majority of the time and yet the clip indicators never light. Limiters are used to squash the peaks to make things very loud without clipping.

 

[Haoleb]

They are at two different zoom levels because they arent the same length. Obviously without using the same tracks, Untouched and then compressed the representation isint very scientific. And with this software I can ramp up the volume until the entire thing is horridly clipped but I just wanted to show visually, what it sortof looks like. Even though the particular compressed tracks may not be clipped, as the californication one is, You can still see the complete lack of dynamic range.

Here's a zoomed in image of the untouched chili peppers track. at just one of the literally tons of clipped signals.

 

[Adam]

You are showing the two tracks at different levels of magnification. One is 1:6168 and the other is 1:12217 and both of those are 'odd' zoom levels. The higher the zoom ratio, the more compressed things look which is not to say that the second track isn't more compressed than the other.

Good eyes, MDS! I thought the second one was at a higher magnification, but I didn't know where to look on the chart.

 

[MDS]

And with this software I can ramp up the volume until the entire thing is horridly clipped but I just wanted to show visually, what it sortof looks like. Even though the particular compressed tracks may not be clipped, as the californication one is, You can still see the complete lack of dynamic range.

Yes, Californication is visibly clipped and that is pathetic! Sound Forge has a preset called 'Maximize Volume' and it performs RMS Normalization to -6 dB and applies a limiter so it doesn't clip. RMS normalization makes the average level be whatever you choose, in this case -6 dB. It sure is loud but I'd never want anything like that.

Keep looking at other tracks and you'll probably find some that would appear to have the dynamics totally crushed but actually sound very good.

By the way, what program is it that you are using? I notice that it is showing sample counts at the top instead of time.

 

[Haoleb]

Yes, Californication is visibly clipped and that is pathetic! Sound Forge has a preset called 'Maximize Volume' and it performs RMS Normalization to -6 dB and applies a limiter so it doesn't clip. RMS normalization makes the average level be whatever you choose, in this case -6 dB. It sure is loud but I'd never want anything like that.

Keep looking at other tracks and you'll probably find some that would appear to have the dynamics totally crushed but actually sound very good.

By the way, what program is it that you are using? I notice that it is showing sample counts at the top instead of time.

Program is called Creative Wave Studio. Part of the bundled Creative software with the Audigy 2 soundcard I have.