Distortion in Tracktion

[McLilith]

Does anyone get distorted audio in Tracktion?

Edited: I have solved some of the distortion problems I was having. It was stupid user error.

However there is still the following issues:

1)
I have noticed a few instances where a rendered piece would be fading out to silence, and there would be a gritty distortion as the piece faded to silence. It would be somewhat subtle, but it definitely be there.



2)
Also, I have some very clean sine wave test tones that I have tried playing in Tracktion. These are WAV files that play with no apparent distortion in any of my WAV editors, and no apparent distortion in Sonar4. The amplitude of these sine waves is -12dB. There is no chance of being near clipping. Lower pitched test tones, such as 60Hz or even 440Hz, play fine in Tracktion. However, if I play a sine wave of 4,000 Hz or 8,000 Hz, I get serious distortion in the audio.

I'm including two screenshots, taken with Bram's nice utility "s(M)exoscope":


The sine waveform at 440 Hz


The sine waveform at 4,000 Hz

The 4,000 Hz waveform both looks bad and sounds bad. Notice the angular sections of the waveform, near the peaks.

A 4,000 Hz sine wave should play without distortion in Tracktion. This same WAV file works in my other software without distortion.

Please, help me if you can.


Thanks,
McLilith

[dry bones]

I occasionally get clipping distortion with VSTs in Tracktion: what I usually do is click on the track volume filter, and when the volume properties section opens up click 'apply to MIDI velocities' and reduce the MIDI volume until the clipping goes. Some VSTs- Crazy Ivan for example- take great delight in really messing around with volume, so this method may not always work.

[Mr. Tingle]

I've never had any such problem, so you'll be glad to know that there is nothing wrong with Tracktion. As to your current situation I have no idea.

[McLilith]

Thanks for the replies, dry bones and Tingle. I have solved the problem of the VSTi that had distortion at low levels. (User error)

I updated my first post, and there are still two issues to resolve. Please read my newly edited first post again.


thanks,
McLilith

[cbit]

There _are_ things wrong with tracktion

Theres a bug in tracktion that prevents it from properly rendering setions that include audio clips whose pitch has been non destructively increased in tracktions arrange window.

The higher the audio clip has been 'pitched', the more clipping the rendered file will exhibit.

[McLilith]

There _are_ things wrong with tracktion

Theres a bug in tracktion that prevents it from properly rendering setions that include audio clips whose pitch has been non destructively increased in tracktions arrange window.

The higher the audio clip has been 'pitched', the more clipping the rendered file will exhibit.

Okay, that helped me find the problem with those sine wave recordings. They were recorded at a higher sample rate than my project's sample rate of 44.1 kHz. I guess I had assumed that Tracktion would automatically convert the format of the WAV file without audible distortion. It now seems that mixing sample rates of imported audio clips is a definite taboo.

When I increased my project's sample rate to match the imported files, the distortion went away. It appears that I'll have to convert any mismatched files in an external program, before importing them into Tracktion. I can live with that.


So, this leave me with only one unsolved problem: the grainy distortion on fade-out of some of my compositions. It isn't very loud, and I can live with it, if need be.

I appreciate everyone's assistance. You have been most helpful.


Thanks,
McLilith

[P.T.]

That distortion on fade out sounds like a dithering problem. Are you rendering at 16 bits without dithering?

Do you have that problem in other hosts? If not, are the other hosts set to automatically dither?

[McLilith]

That distortion on fade out sounds like a dithering problem. Are you rendering at 16 bits without dithering?

Yes, it turns out that dithering was turned off. I was rendering to both 16 and 24 bit WAV files at various times. I'll have to try some more tests later, with the dithering turned on.

Thanks,
McLilith

[McLilith]

Okay, I just tried playing an imported 24-bit WAV in Tracktion, which has a slow fade in. I made sure that the WAV sample rate and the project sample rate were matched.

I noticed that if dithering was enabled for my audio card's output, I got ragged distortion on the sound. When I turned off the dither, the ragged noise went away.

I guess I won't be using dither.


take care,
McLilith

[IIRs]

I've never heard Tracktion's dither cause distortion. I do find the mda dither slightly smoother sounding however.. maybe try using that in the master section with Ts dither turned off. (Make sure the master fader is at unity)