Automating Tempo results into different render lengths


I’ve got my Tempo controlled by an LFO and when I render my song it doesn’t render the proper amount of the song. Every time I render the song has a different length and either cuts off early or goes past the end and loops back to the beginning. I basically have to keep clicking render and hope I get one that at least passes the end of the song and then use another program to chop off the excess audio.

Repro steps:

  1. Start up Renoise

  2. put an LFO on the master track.

  3. Assign it to “Mixer & Transport” - “BPM”

  4. Render song

Expected Results:

The Rendered clip will both have and not exceed the full length of the track

Actual Results:

The Length of the audio rendered will either be shorter or longer then the tracks length. If it is shorter it will cut out the end of the track. If it is longer it will loop to the beginning of the track.


The LFO Changes between 2 shapes during the playback of the song, sine wave and triangle wave.

I have also noted that the timer that shows the length of the clip in the top right corner sways up and down while the song is playing, or while it is paused. It does not accurately represent how much time has passed.


An LFO, unlike the automation envelopes, has no clear defined end result, therefore it will break your render and the devs generally ask you to avoid it. If you still want to keep it, simply add padding your render amount.

When I shift the BPM using automation and then ‘Render Song to Disk - Offline Mode’ it causes an incorrect render, looping back and replaying part of the song over or cutting the song short when rendering.

Steps To Reproduce

  1. Launch Renoise

  2. Open attached .xrns file ‘BPM ERROR RENDER’

  3. Make note of the Hydra on the Master track, it outputs to CT>Mixer & Transposition>BPM, and modulates at different parts of the track.

  4. File>Render To Disk

Render one file in Realtime, and one in Offline Mode. Notice that the file rendered Offline will be 15 seconds longer, and you can notice that during the Render process it loops to the beginning of the track and plays a portion of it.

Expected Results

A rendered waveform of the song with exact duration.

Actual Results

A rendered waveform which contains a portion of the beginning of the song at the end of it.

I guess I should have been more clear, there’s no clear end result if you use any meta devices to control such parameters as LPB and BPM, it can break the render

Whilst this may be completely unhelpful to the op or others, I wonder if this error could be exploited for some glitchy results?

Edit: no real interesting results here, so I guess this post was entirely unhelpful :smashed: