#5thAvenueBlogs | Cutting samples and the importance of zero crossings [Blog]
Toronto, ON – Sampling is a major element of hip-hop production; just about every beat-maker has used one in their music-making life. Digging old tracks for instrumentals or looking for that right vocal hit is always fun, and now with digital audio cutting is easier than ever. Don’t be fooled though; you need to make sure your cuts are precise or you’ll end up with nasty clicks and pops. In this blog, I’ll help you polish your cutting skills.
A college instructor of mine had an analogy about poor cutting; he called it shit soup. So, you invite your friend over for lunch and you serve him a bowl of soup. Then for some reason, you shit in the soup. He gets mad, so you scoop out the shit for him. You’re now left with the soup that once had the shit in it that no one wants to eat. Below is a photo of a poor cut.
Poor cutting is the same; it can leave artifact like clicks and pops that are difficult to remove later down the line. Certain plug-ins can help you remove noise, but it’s better to get your fundamentals down and do it right from the beginning. This is a pretty straightforward explanation of how to cut cleanly.
Let’s say you’ve got a 4 bar loop that you want to sample. You’ve identified your beats and you’ve made your rough cuts, now to focus on getting the zero crossing. The zero crossing is the point in the waveform that has the least amount of energy, and it is also the same position the speaker is in when it is at rest. Where the waveform meets the center horizontal line in your DAW that is where you want to cut. The more you can zoom in the better to make sure it is as precise as possible. In the next photo, I’ve indicated 3 points where there are zero crossings.
I usually advise to cut the start of your sample first, that way you can make sure the timing of your sample is still good. Once you’ve made your first clean cut, go to the end of the loop and cut again. If you’re looking at the waveform from an ultra close view point, you have to remember that you are looking at it by samples, so if you off to one side to get to a zero crossing, odds are you won’t affect the timing of your sample. With that being said though, your ears are the final judges of that. The idea is that when you combine your loops, the stitch point is at a zero crossing.
If you’re simply cutting a vocal sample that is not looped, make your cuts at a zero crossing, or for quickness, you can also use an automatic fade. This comes in handy when you just need to keep ends clean, but you must make sure your fade is long enough to be effective. Some razor thin fades don’t translate well during the bounce.
It doesn’t matter what digital audio workstation (DAW) you use, these principles are all the same. The only difference that may come about is that some will automatically re-shape waveforms with fades to ensure the zero crossing is met. If you are not sure, or if you want to manually cut and fade, you can follow what I’ve written above. It is not difficult by any means, but paying attention to these details will save you time down the road.
And if you’re curious…The waveform is a replica of the movement the speaker cone makes when it audibly replicates the sound of the digital audio file. Below the line (negative) is when the speaker moves inwards. Above the line (positive) is when the speaker moves outwards. The artifact sound of a click or pop is the sound of the speaker cone rushing to get into the position of the waveform. It’s the jerking noise of a poor cut.