Punch-In/Out noise

[Minds Eye]

I hear "clicks" in my sleep

I'm running Cakewalk PA9, with plenty of disk and memory to keep it happy. Most of my recording I do using the loop feature which works great. I've just recently started trying to use the punch-in/out on some more complicated tracks. The result is a clip or artifact at the beginning of the punch-in and at the end. I've tried to minimize it by recording to another track, then doing a cut and paste process, but that seems to defeat the purpose a bit. On drum tracks it's not as noticable, but on bass, it's bad.

Anyone out there managed to avoid this? Other than those that always get it right on the first take

[Shailat]

I don't own cakewalk but the problem you seem to mention can be from punching in at the wrong spot.

Does it click when you punch in at a spot were it's total silence?

[dachay2tnr]

I believe Shailat is right. I use the punch in feature all the time with no problems with clicks, etc. However, you should start and end the punch in in areas where the track has silence. In other words, if it's a vocal, punch in the entire phrase, rather than trying to punch just a single word. Same logic would apply to instruments.

The artifact you are hearing is the seam between the old sound and the new sound. I had the same problem with a cut and paste when I tried to cut something in the "middle" of a sound. You need to make the cuts (and punches) in silent areas.

[Minds Eye]

Thanks for the info!! In the song I'm working on the bass doesn't have a silent area to start the punch at...except the beginning. I've tried to set the insert point at a zero crossing, however the punch-in itself doesn't end up at a zero crossing when it's inserted. I've performed the same function many times with a Roland VS-880 with no artifacts at all. Are there any setting that may need to be changed?

[Shailat]

Set the punch in for an attack of the start of any note but !!! play before with the track and then punch in.
Set the punch in on auto so you can play with the track so you don'r have to fidile with it while playing along.
Use the crossfade if needed to seam it together.

I would first make an exact copy on a new track and punch in on that as not to ruin with a bad punch the whole bass part.

[skippy]

It is extremely difficult to punch in (or splice) in the middle of a note without creating an artifact, even if you do sample-accurate editing and pick a zero crossing. The reason is that the ear is extremely sensitive to phase differences. Just picking a zero crossing on the waveform isn't enough.

Why? You can think of the waveform as being built up by summing up a whole bunch of sine waves of different frequencies and phase relationships (the Fourier equivalent). You have the fundamental, and a bunch of partials. The visible waveform is dominated by the fundamental- but to get an artifact-free splice, you have to have the phase of the majority of the partials right as well as the fundamental at the point of splicing.

Here's an example: Let's pick a really simple timbre which is just a fundamental and its first partial, one octave up in frequency, 6dB down in amplitude. That's it. And let's say that you want to splice it at a falling zero crossing (the signal is swinging from positive to negative). Bad news- you can have two flavors of negative-going zero crossings in this case: one where the fundamental and the first partial are both going negative, and one where the fundamental is going negative, and the first partial is going _positive_.

If you splice -- to --, you can't hear it. If you splice -- to -+, you _can_: the discontinuity in the first partial creates a transient burst of HF partials that stick out like a sore thumb, *even though the fundamental is spliced correctly*. You can hear the click, even if the waveform _looks_ decent in an editor.

Picking the right point to splice is crucial, and to make it inaudible, you have to match phase relationships of the fundamental and many (if not all) of the partials. How many? That's a trade secret for many of the high-end MI manufacturers: splicing together loops is a very useful data compression scheme which has been used for a lot of very well-respected semi-sample-driven keyboards. It ain't easy to do, though- it takes a lot of CPU time to do _right_.

[Minds Eye]

So if I understand all this, dachay2tnr is successful using punch-in in Cakewalk because he selects a section where the wave is flat. The Roland works because they use a more complex algorithm than Cakewalk to determine the best splice point. I'll play around with it tomorrow using Shailat's suggestion and see what I can come up with.

Thanks again for the info and suggestions. I'll post what I find tomorrow.

[Minds Eye]

Spent some time playing with the punch in. Was not able to eliminate ALL the artifacts each time, but using Shailat's suggestion along with the information skippy provided, I was able to come up with an exceptable result. I selected a point at the beginning of an attack to start the punch-in. If it produced an artifact, I hit undo a couple times to get rid of what I just did than adjusted the start of the punch-in one or two ticks before the attack. In some cases this still produced a noticable artifact so I hit undo again and adjusted two ticks past my original starting point. Between the two positions I managed pretty good results. In some cases I could still hear an artifact when I'd solo the track, but in all cases it was small enough that it got lost with everything in the mix added.

Thanks again for the help!!