Getting Distortion - I think?

Maybe I am just hearing things and being crazy, but over the last week it seems like I am starting to hear some distortion from my system. It isn’t my speakers or headphones.

If it is my system / Cantabile what should I start looking for.

I am running the latest version of C3 on a Win 10 64 bit system with 16 GB of ram and a 4770 core-i7 with CPU throttling turned off in the bios. Running through an RME FIreface UCX interface, running at 44,100Hz and 128 Samples

My system load stays under 35% (45% with sustain pedal held and lots of notes played), but can idle between 5-15% and memory used is only about 3GB. There are page faults ( not sure what these are ) that show up, sometimes between 1 and 6. I noticed these page faults showing up with the system even idle.

It seems like the distortion is VST independent and it seems like it occurs when I hit a greater number of notes at higher volumes. I don’t remember this distortion being present before.

Any suggestions on what to check?

P.S. - Could it be my output ports are running too “Hot”. I was messing around a little with this and it seems distortion comes into play when these are peaking. The output port outer box turning Orange is Clipping? It appear that when this happens the distortion occurs. Maybe I just never noticed it till now.

Hi John,

Page faults between 1 and 6 is nothing - you can pretty much ignore that as being very normal. The load levels seem normal to - but check if they’re spiking at the time the distortion occurs.

An yes - any level meter’s border lighting up indicates clipping - which can be tolerated if it’s dialed down again before actually hitting the sound card.

If you can easily reproduce the problem the other thing you can do is record the audio output with Cantabile’s audio recorder and load it up in an audio editor and have a closer look for clipping and/or drop outs.

Brad

Brad, I am pretty sure it was audio clipping. I had never really heard it or noticed it, but I think my volume pedal had been at a higher setting which increased the output of most VST’s. When I did a test to intentionally cause clipping, I was hearing the same type of distortion.

Based upon your reply my question is: Does actual “True” clipping occur as a “Summation” of the path “Gains” and not based upon an individual output gain setting. So clipping in one part of the path can be eliminated, say by a low final output gain. Or clipping can occur if settings are close to clipping all along the path and then the final output gain is +Too many Db’s?.

Should I feel the need to investigate further will something like “Audacity” will give me a visual (of the recorded .wav file) to verify clipping and confirm what I am hearing audio wise?

Hi John,

Cantabile’s audio processing pipeline is all floating point so any signals that exceed the range can be dialed down by a subsequent mixer to bring it back into range and avoid clipping. The one thing I can’t guarantee is how any effect plugins deal with this. Most should handle it fine, but I can’t say.

As for inspecting the recorded output, if you’re recording in integer format, clipped samples should appear at the maximum/integer value (ie: -16384 and 16383 for 16-bit integer). If you’re recording in floating point format I’m not really sure how Audacity would show out of range signals.

Brad