DSP chain differences on track and sample FX chain


I’m still somewhat new to Renoise 3 so please bear with me in case I oversee something, but here’s the issue:

I noticed today that the same DSP chain sounds different if it is applied to whether a track or the per sample FX chain. I checked all settings but I just couldn’t find out what causes it to sound different. Strictly and logically taken it shouldn’t sound different, but strange enough it does. The track DSP chain sounds definitely clearer, while the per sample DSP chain is kind of muffled.

Is there an explanation to as to why that is? Sorry I don’t know how else to put it, I hope my text makes sense…

It might be clipping, because FX render ignores track headroom and track faders.

Sorry, no. I’m not talking about FX render, I’m talking about applying DSPs per sample in the Renoise sampler.

I have checked the headroom as well, but even compensating either tracks by 6 dB there are still clear differences.

Can you please upload a small example XRNS song that clearly demonstrates the problem?


The track DSP chain sounds definitely clearer, while the per sample DSP chain is kind of muffled.

Ahh, ok. I see/hear what’s going on.

This is related to the track headroom setting, and specifically how it’s applied slightly differently to a track DSP chain vs an instrument DSP chain.

Assuming that you stick with the default track headroom setting of -6 dB…

In your instrument DSP chain, add a Gainer at -6dB as the first device, and another Gainer at +6dB as the last device, like so:
5489 renoise-instrument-dsp-chain-track-headroom-compensation.png

This will ensure that you get exactly the same output as the track DSP chain.

Alternatively, you can simply set your song’s track headroom to 0dB, so that the track and instrument sound identical, but then all tracks in Renoise will be louder than before, so you should take care to lower your master volume level to avoid any potential clipping.

So it was the headroom after all. Your solution worked, thank you dblue! :slight_smile:

I guess (without listening to the example, just judging by the screenshot above) the main culprit for such problems will be distortion plugins. Most distortions/waveshapers are very sensitive to the level of the input signal they’re confronted with. Unless you squash/limit/maximise right before the plugin. I actually use this effect, automating the level and/or filter in certain ways right before a distortion plugin to modulate a sound.