New Render bug with track inserts

Today I discovered another bug while making some files.

Keep in mind the only reason I found this bug is because I’m working around another bug which is a crash I get with UAD and FabFilter together on a montage master, PG knows the bug.

Anyway, I try to work around it but sometimes I get a montage that constantly crashes when rendering, so my solution is to move my UAD BAX EQ from the montage master to each Wavelab track. Not ideal but a the only fix I see for my first bug.

The new bug is that when rendering files with my montage setup, which is two audio tracks in Wavelab, each audio clip is staggered from track 1 to track 2 back and forth. This bug is very clear and problematic when songs overlap, because now I get a tick on the rendered output files when they are played in line.

When I can keep the UAD BAX EQ on the montage master as I’d prefer, there is no issue. When I have to move the UAD BAX EQ to each audio track in Wavelab, the waveforms are not continuous when they should be.

I will attach a screen shot of where two songs overlap. One is with UAD taken off the track inserts, and one with UAD on. Clearly the latency or rendering is not perfect. I haven’t had time to test other plugins or just UAD only. The screenshots are not perfect, different zoom and waveform zoom but you get the ideal, one is not perfect and one is.

Initial testing shows that DDP images don’t have this problem but rendering WAV files of each CD track has this problem. Maybe it’s a clue but I will verify this to be true.

Do you mean that the same (clip + track effect), on 2 different lanes, without offset (below each other), render differently each track?
I can’t reproduce this here (using other plugins).

What I mean is that I have a montage with songs that overlap and run together, the overlap is created by using two Wavelab montage tracks. If there isn’t a UAD BAX EQ on the track master for both audio tracks in the montage, and I render a WAV for each “CD Track”, the rendered WAV files are sample perfect, and don’t cause a tick or pop when lined back up and played back to back as I would expect.

When I have UAD BAX EQ on both of the Wavelab two Wavelab montage tracks (not audio track or regions), and render WAV files of each “CD track” track for the album, the rendered files are not sample perfect and cause a tick or pop when lined back up and played back to back.

Something must not be right with the Track insert latency compensation. I know we had similar issues with montage master and high latency plugins so maybe it’s not just UAD, but any high latency plugins.

You should send me a test montage so that i can see exactly what you mean. But use steinberg plugins.

Will do, do you know the highest latency Steinberg plugin I can use as a test?

Here is a small montage session I made:

I used a test tone to easily show the problem. The original source tone is included in the folder with the montage files and the renders I produced, as well as screen shots of each render situation at the point where the two rendered files should be seamless

In the folder there are two montages, each with only Steinberg plugins.

Montage 1: no clip plugins, multi-band compressor on each of the two Wavelab tracks. Steinberg EQ and Brickwall Limter on the montage master for fun.

When I play the live montage, the transition from clip one to clip two (aka song one to song two) sounds perfect. PROBLEM: When I render a WAV file of each region based on “CD track” the two files are no longer seamless when I re-align them in a new montage to test. There is a visible gap.

Montage 2: I took the inserts off the Wavelab montage tracks and the rendered files are perfectly seamless when I bring them into a new montage. When I play them back to back there is no pop or tick between them, just smooth.

So, in the folder you see my two montages described above, and a Render folder containing the files I produced from each montage. You should see a problem when you line up the files from render folder 01.


What’s more interesting is that the problem doesn’t occur if I render a DDP, just when I render WAV files of each region based on “CD track” markers.

just a thought:

  1. Are your CD track markers quantized (function in the wizard)? I believe the values are automatically quantized when sending to DDP but are not automatically quantized if you’re rendering wavs from cd tracks.

  2. Have you tried putting all the clips on one track (track 1), say using the rubber band to select all the clips on track 2, holding shift and moving them all up into track 1. They’ll be overlap of the clips in track 1 but that should be ok.

I’ll look into the quantizing but I wasn’t aware that anything special had to be done if you are just rendering WAV files from CD track splice markers.

I thought it would just break my montage up into WAV files at each splice marker, and for songs that overlap or are continuous, there would be no ticks between them when I re-load the rendered files to test.

I usually quantize anyway to ensure there are no issues with anything between tracks on any format.


Quantizing CD markers still produces some problems on what should be seamless files.

These two particular clips have no clip effect plugins in the montage, and I just UAD and FabFilter on the montage master. No track inserts or global.

This attachment is what they look like when pushed next to each other. You can see there would be an audible tick.

What I’ve determined with Wavelab, just don’t use any plugins at all anywhere, even the Steinberg ones.

The initial problem is clearly plugin related. With just one plugin on the montage master and some plugins on various clips, I don’t have the tick and the tracks that need to be seamless are sample perfect when I butt the rendered files together.

I’ve tried adding 3 different EQ plugins on the montage master before my limiter and they all induce a problem when butting the seamless rendered tracks together. The files are no long sample perfect and a tick is audible.

I discovered the track insert bug when I was scrambling for a workaround for 2 different bugs now.

Since I’m in the final steps of a project, I have to find a workaround but I think this could be the end of my time with Wavelab. Just when I thought things were good, these things happen.

What’s even more confusing is that I found an EQ I can insert before my limiter that solves the problem between some songs, but not all of them. Some rendered tracks are seamless when re-sequenced together, and some are not.

I get the feeling that Wavelab latency compensation and rendering are not 100% on the same page. The fact that two songs that have no clip inserts, only working from the same montage master effects would not be seamless after rending and putting them back to back.

Bob99 was right to draw your attention on CD marker quantization (A CD frame is 588 samples, there are 75 per second).
When you render CD tracks individually, the exact part between markers is rendered, but the markers are written to a CD-quantized position (WaveLab does the quantization). I think this is what you observe.
On the montage you provide, the CD markers are not CD quantized.

How do I render WAV files from a montage that has continuous audio and make sure that the rendered files do not have any pops or clicks between them when I line them up back to back?

Why is there a big gap at the start of rendered file 02 in the files I provided? It’s not in the montage and doesn’t happen when the plugin used on the track insert is moved to the montage master.

Guys, the track marker quantization doesn’t seem to be the problem.

Here’s the same test with the CD track markers quantized before rending the files this time:

The results are exactly the same.

In render folder one, track 02 Song 02 has 2ms of silence before the tone starts

In render folder two, the files are perfect.

The difference is that montage 01 has Steinberg Multi-Band compressor on each of the two Wavelab audio tracks.

See this image for the problem:

See above, but to be clear, this is what I mean when I “render CD tracks individually from a montage”. I have only used splice markers. I want everything between the markers to be rendered. It has nothing to do with a CD really, I’m rendering from the main original source montage.

The problem is that the resulting files are not perfect when I test them. Songs that are connected and sound fine in the original montage, now have a pop between them and it’s clear the waveforms no longer align.

It can’t be related to the markers or quantization because I’m getting different results when I add or remove plugins. The markers in my real montage are quantized however.

Here’s a screen shot of what I mean by “render CD tracks individually from a montage”.

PG and jperkinski I apologise. I should have said I was just offering possible test workarounds, not solution. WAV files rendered from CD track markers ‘should’ be seemless no matter what (quantize or not), because they ARE seamless on live stuff I’ve done for years, with CD track markers quantized AND not quantized. But I don’t use plugins at point of render. Seems to me what jperkinski is experiencing is a bug in something and shouldn’t be happening regardless of what I’ve suggested for troubleshooting. Sorry.

Hey Bob, no worries and I appreciate your help. Sometimes the problem is a silly oversight but I think I’m beyond that possibility at this point.

This is getting convoluted because it’s a workaround for a workaround and getting harder and harder to explain.

Basically, yes, the files I’m rendering are not seamless when they should be. They are seamless in the montage. Only a CD track splice marker is being used. As a precaution, I’ve quantized all markers to CD frames. I’m telling Wavelab to render WAV files from an original montage based on regions defined by CD track splice markers.

I’ve literally spent all day trying different scenarios to get this montage to render proper WAV files that are as seamless as the montage is, and the DDP renders which have been perfect which is kind of baffling.

The test montage I’ve uploaded is a side issue I found when I moved my EQ to the 2 track inserts rather than the montage master.

It’s the kind of problem that could no unnoticed forever unless you are working with songs that need to be continuous and seamless.

All I want to do is have 1 EQ, and 1 Limiter on my montage master. I’m even compromising by not using the UAD BAX EQ and trying Waves, FabFilter, iZotope. All produce the same results.

Once I remove the EQ and just use the limiter, the rendered files are okay.

Thanks for your effort and last files. Now I see what you mean. Still, I can see this is a plugin problem (even the Multiband problem in your case). The problem does not happen for instance with the Peak Master (which have a long latency too).
What happens is that the second CD tracks start with about 2 milliseconds of the end of a clip (the main clip of the 1st CD track). This means the plugin has only 2 milliseconds of audio to process, which is less than its internal latency, that is, the minimum number of samples it needs for proper processing. Still, a plugin should be able to deal with that, but this particular case is certainly rarely tested by the plugin builders.
Therefore, if you need to process such small audio sections, verify that the plugins can do so.