Playback issues - layers with audio drop out


I am experiencing an unexpected playback issue in SLP9 and want to double-check with you.

My source material is an environmental sound recording. I am cutting a discontinuous spectral selection across the audio to a new layer (“cut special”). Then, I stretch the new layer using the Transform tool. I am also creating other layers with different spectral selections from the original material, with no further processing.

The problem occurs when I simultaneously playback the stretched layer with any other layers. The transformed layer “mutes” the other/s when there is no sound, acting as a “gate” of sorts.

The stretched layer consists of short audio intervals with silence between them. If any other layer with continuous sound is active, it is only audible when audio is present on the problematic layer (i.e. I hear both mixed, as you would expect); but there is no sound otherwise. If I make inactive the transformed layer, the audio behaves as usual.

Interestingly, if I “Merge Up” the continuous layer with the transformed one (either one placed above/below the other), the resulting layer has “holes” (i.e. the constant layer gets cut up accordingly to the audio present in the problematic layer).

At first, I thought it was a bug, but I reproduced this problem using different source recordings. I would not expect this to happen, and it seems to be related to the Transform operation.

However, I tried reproducing it with a new project using noise generated within SLP9 as source material. Everything behaves as one would expect.

Also, in one of my tests, I experienced audio drops when the transformed layer plays simultaneously with others. (EDIT: further info and screenshots on this case in a reply post below in this thread).**

Any ideas? Did anyone experience something similar?

I appreciate any help you can provide.
Many thanks in advance.

example screenshot 1

example screenshot 2 - layers merged (“merge up” operation)

Further info on the issue. The waveform display shows no continuous line as expected (a continuous horizon line always shows up for every layer, even for empty ones). It makes sense with the audio drops, but why does it happen?

The screenshot attached shows the waveform display of the above example, with the transformed layer causing the issue.

A variation of this problem. This is from the other test I mentioned at the end of my first post. In this case, drops in the audio appear at both sides of audio content within the problematic layer (i.e. transformed with 200% stretch). The drops can be seen in the zoomed waveform display (please, see the screenshot attached). When this layer is played simultaneously with any others, it cuts their audio. However, if the layer is inactive, the audio behaves as usual. Again, if I merge this layer with any other, the resulting layer has those holes.

So what is causing these discontinuities in the signal?

more screenshots demonstrating the issue

the layer with audio dropouts merged with another layer with a continuous signal

In-regards to silence/mute of the other layers: That sounds to me like you’re cutting to new layer. When you cut to new layer you’re actually cutting the audio material from one layer to another (meaning you are moving audio in a non-destructive way from one layer to another).

Thanks for your response. Indeed, I am cutting (or copying) audio material to new layer/s. However, this doesn´t explain the audio dropouts I am experiencing. Only when the specific layer that was transformed is active, this layer is silencing/muting other layers where there is a signal present.

The audible dropouts correspond to silent parts within this layer in the first example or the short holes visible in the waveform in the second.

To clarify, there is no audio material missing (which I have moved/cut) that wouuld explain the dropouts in the output signal. I would expect simultaneous playback of any audio material present in every active layer, which is not happening in those instances.

Hmmm, I’m not quite sure I understand completely. If what you are describing does indeed cause audio dropouts then that could very well be a bug.

Can you do a screenrecording of your problem so that what you are describing is understood a lot better? Maybe a screenrecording would give a better insight into exactly the problem you are describing. OBS is free and is flexible with it’s settings

Thank you. Yes, it seems like a bug. It doesn´t happen when I do the same process (i.e. cutting/copying a spectral selection to a new layer and applying transform-stretch) using generated noise as source material in a new project within SPL9.

I will continue testing with other source files to figure out if it is systematic or not; and consider preparing a screen-recording.

Maybe not so clear with the screenshots and explanations above, but I hope @Robin_Lobel or someone can provide some hints on what´s happening. Thanks.

Further updates on this issue. I exported audio of the individual layers causing the dropouts on my two projects. There are glitches in the signal corresponding to the timing/pattern of the dropouts.

My conclusion is that there was corruption in the audio caused by the transform/stretch operation. I repeated the same operation in one of the projects, and the audio is now fine (no dropouts and the exported file looks correct).

I will continue experimenting with transform operations and see if this will happen again. Hopefully, this was a random bug. However, it seems weird that the same problem in two slightly different variants happened with different projects and source files.