I've recently been experiencing digital distortion on low frequencies, even though the overall level isn't clipping. I can reproduce it by recording myself walking heavily around the studio. It sounds like an 8 bit recording.
 
At first I thought it was my mic pre, but I tried another interface and got the same result. Then I thought it might be my (desktop) computer, but I hooked up the interface to my laptop and got the same result. Finally, I tried another DAW...
 
Crystal clear. 
 
I would assume it was something with the Lexington update, but my laptop is still on Ipswich and when I was on Ipswich on my desktop I didn't have the issue. My best guess now is that there was a recent Windows update that's interacting with how Sonar handles audio, but I really have no idea.
 
Regardless, anybody else encountering this? Anybody figure out how to resolve it?
 
Edit: Actual solution in post #16.

If you zoom right into the recorded waveform, what do you see?
 
In my years using Sonar, it has produced the following types of behavior:
 
Standard clipping (tops cut off), This is normal. Low frequencies may not be heard with mid-range monitors or headphones, but the clipping harmonics can.
 
Ripdowns (little sections of the waveform go all the way to the negative side, usually when the positive side clips)
This happened with ASIO up to X3e, IIRC
 
Ripnulls (little sections on both sides of the waveform go to the center line)
This is new with certain interface drivers.

jpetersen
 Ripdowns (little sections of the waveform go all the way to the negative side, usually when the positive side clips)
This happened with ASIO up to X3e, IIRC

Just FYI, this can still happen if the digital audio clips (e.g., interface level too high when recording).

benjaminfrog
I've recently been experiencing digital distortion on low frequencies, even though the overall level isn't clipping. I can reproduce it by recording myself walking heavily around the studio. It sounds like an 8 bit recording.
 
At first I thought it was my mic pre, but I tried another interface and got the same result. Then I thought it might be my (desktop) computer, but I hooked up the interface to my laptop and got the same result. Finally, I tried another DAW...
 
Crystal clear. 
 
I would assume it was something with the Lexington update, but my laptop is still on Ipswich and when I was on Ipswich on my desktop I didn't have the issue. My best guess now is that there was a recent Windows update that's interacting with how Sonar handles audio, but I really have no idea.
 
Regardless, anybody else encountering this? Anybody figure out how to resolve it?

What happens if you bypass the effects (type E) or increase the latency?

Hi, Folks. Thanks for your responses. The audio isn't clipping. It never hits 0 dBFS. The only effect going is IK's ARC room correction plugin on the master buss. I don't hear any distortion when monitoring while recording, but the distortion is getting printed to the clip. Here's a screenshot from RX (never added an image to a post, hope this works). You can see the bizarro harmonics that are being generated.
 
Edit: Can't figure out how to insert the image, but here's a link to it:
 
https://drive.google.com/...p9e_6MKcWVMSDVuOVpmZ00

Maybe some process in the computer is interfering with the recording process? I had something somewhat similar happen when recording to an outboard drive connected to the motherboard's USB port, although it was more like clicks and pops. When I installed a USB port PCIe card and connected to that, the problem went away. 
 
Have you disabled any of those "HD" graphics drivers that install with video card software. or checked the performance with Latency Mon to see if anything weird is happening with your system? Also, what happens if you bypass ALL effects and increase the latency? Inquiring minds want to know...not because your computer/interface isn't capable of low latency operation, but because it might help reveal whether something is hogging the computer's CPU. 

Craig is right. Same thing happened to me. Culprit was nvidia driver. Discovered,as he said with latency mon. 

Thanks, Guys. Fortunately or unfortunately it's not happening now. I'll try your suggestions though, Craig, the next time it does. I'm also wondering if there might be an electrical issue or some other non-computer-specific cause, given that it was happening on both my desktop and my laptop and now it's not happening on either one. Anyway, thanks, everyone, for your input.

Glad it's working for now, but please check out the Friday Tip of the Week for Week 35 for info on how to remove pernicious/unneeded drivers that degrade performance.

A bad ADAT Cable, or connection can cause strange things as well.