Distortion when monitoring using soft pass through

Hello Audacity team. Thanks for the continual hard work and effort that is put into making the software.

I’m having a problem with distortion while monitoring through “soft through” checked in audacity preferences

MY SETUP:

Analog mixer stereo out running into stereo line in on macbook. And Headphones connected to headphone out on macbook.

When recording (or PAUSED recording) as I bring the input up in Audacity, I begin to hear artifacts attached to the clean signal, and as I bring it up more, artfacts slowly become more and more distorted.

Of course I am not red lining or clipping in Audacity, and my analog mixer is not clipping or distorting. I have connected my headphones to mixer and signal is clean. Also to note when I play back the recording in audacity there is no distortion.

What’s also interesting, is if I push STOP on audacity the clean signal (that I am recording) obviously cuts off, but now the artifacts and distortion are isolated. So in that moment Audacity is stopped, nothing is on the meters, yet that distortion is playing. Then about 30 seconds later it turns off.

Thanks again.

DC

So in that moment Audacity is stopped, nothing is on the meters, yet that distortion is playing. Then about 30 seconds later it turns off.

So Audacity isn’t the only thing running on your machine. That’s Not Normal.

Pull up the dock usually at the bottom of your screen and see how many little black or white indicators you have. Close the ones that don’t say “Audacity.” Right-Click > Quit or Control-Tap > Quit.

Now unplug the network if yours plugs in and turn off WiFi and Blue Tooth—usually upper right on a Mac home screen.

Restart Audacity. Does it still do it? If you had a tangle of oddball sound routing and sound apps, Audacity might very well crash. That right there tells us about your machine configuration.

Koz

It’s normal for Playthrough to be late or with an echo. It’s super difficult for Audacity to feed you your own sound back to you in real time. If you’re overdubbing, it’s strongly recommended you use a USB sound adapter with Zero Latency Monitoring.

The G-Track is one microphone which will do that.

Koz

So in that moment Audacity is stopped, nothing is on the meters, yet that distortion is playing. Then about 30 seconds later it turns off.



So Audacity isn’t the only thing running on your machine. That’s Not Normal.

Actually Audacity is the only thing running.
Please note: That yes, I can still hear the distortion and artifacts playing because the mixer is still delivering sound to the input. And like I said when I stop Audacity from recording I can hear the distortion for 30secs or so, then it stops entirely.

BUT, if I QUIT audacity, the distortion and artifacts go away also.

So…to put all my ideas together…

If I’m recording from the mixer I can hear the distortion in the signal. If I PAUSE Audacity, I can still hear the signal coming from the mixer as well as the distortion.

If I STOP Audacity from recording I no longer hear the signal from mixer but can hear the distortion.

If I QUIT audacity. I hear no signal nor distortion

That about wraps it up! :slight_smile:



Pull up the dock usually at the bottom of your screen and see how many little black or white indicators you have. Close the ones that don’t say “Audacity.” Right-Click > Quit or Control-Tap > Quit.

No other apps open at all

Now unplug the network if yours plugs in and turn off WiFi and Blue Tooth—usually upper right on a Mac home screen.


Restart Audacity. Does it still do it? If you had a tangle of oddball sound routing and sound apps, Audacity might very well crash. That right there tells us about your machine configuration.

Wifi is off bluetooth is off. Problem persists.

I have no problem with latency. I can overdub just fine.

I have no problem with latency. I can overdub just fine.

You may be the only poster in the history of the Audacity forum who ever said those words.

Then about 30 seconds later it turns off.

If that’s not impossible, it’s impossible-adjacent.

Can you see the dancing cartoon question marks over our heads?

Let’s go a different angle. What are the input and output Audacity selections?



If you grab the gray double vertical lines to the right of that panel and pull to the right, the panels will expand to let you see all the words without abbreviations. The other tools will scurry out of the way.

Shift-Command-4 will give you a little cross-hair on the screen. Draw a box around those graphics as above and post it. Scroll down from a forum text window > Attachments > Add Files.

Koz

I have no problem with latency. I can overdub just fine.



You may be the only poster in the history of the Audacity forum who ever said those words.

LOL, well I use audacity for creating dj mixes and track layering, mashups, multitracking, etc., I have no problem recording a song into audacity, then layering another song perfectly in sync…in real time using a turntables pitch drive. You know like dance music BPM stuff. I use "soft pass through’ on, and ‘overdub’ on. I don’t hear any latency.



Then about 30 seconds later it turns off.

If that’s not impossible, it’s impossible-adjacent.



Can you see the dancing cartoon question marks over our heads?

lol

Let’s go a different angle. What are the input and output Audacity selections?

My settings are exactly like what you posted. No different.

Ok,ok after some more testing I have came to the conclusion that my internal sound card has limits. I tried with another device, a boombox and went headphone out into line in on the mac, and I get the same distortion. It seems that I can only push so much volume into the mac sound card before it starts distorting. (This of course is without clipping Audacity, it seems I’m clipping the limit of the soundcard?) I even went so far as quitting Audacity with the boombox playing a CD. Turned the volume down on my headphones coming from the mac, and I could still hear the distortion. So it’s definitely not Audacity. It’s the mac soundcard. The soundcard stays “active” for about 45 seconds, then turns off. And so does the distortion.

Sorryyy, thanks for your guys time!





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in real time using a turntables pitch drive.

That could be one important data point. You may find that if you tried to actually sing into that setup with your own voice coming back to you in real time mix, what latency there is would drive you nuts. There has to be some latency. Your voice has to get digitized, go into Audacity, come back out and get converted to analog. You can do that efficiently, but you can’t do it in zero time. Some software packages “know” what you’re trying to do and shortcut the system by not feeding you your Audacity voice. They use a shortened pathway and can significantly reduce the delay (but it still doesn’t go to zero).

We do lose it if your computer is broken. All of our IF-THEN scenarios go away.

I think we didn’t do the time-honored restart your computer yet. Did you? I tend toward Shutdown, wait a bit and then Start rather than the Mac Auto Restart. Do you get your opening Chong? At least up until the last version of Macs, that’s the Mac version of Windows’ POST—Power On Self Test. But that’s more like “are your services there at all” rather than an exhaustive test. It’s a danger sign if you get the Spinning Beach Ball Of Death while it’s shutting down, so pay attention.

I can’t think of a healthy scenario where a computer would do what your computer is doing. I think I can account for the apparent distortion. There is double sound going to your headphones, but nowhere else. There is significant overload, but only in local monitoring. So once you know that, you can proceed with production and just ignore the gritty audio—until you get it fixed or a different machine.


I’m just thinking about this as I type. Do you have two different connections for Line-In and Headphone Out?

That’s an older 15" Mac Book Pro The 13" MBP didn’t have room for that so it had one connection that would switch. The newer machines have HeadSet connections. It does ring bells when someone says they plugged into their machine’s Line-In connection. Computers haven’t had those in quite a while now. I have a New Inna Box Mini which has both. I think that’s the last model.

Koz

Thanks Koz.

Thanks again. But the problem seems to be the sound card. I was pumping it too much volume. And yes, I have both a line in and line out.

Anyway, I learned through trying various sound sources like my mixer, my boombox, that their levels can exceed what the soundcard allows. Which is where the distortion and crackling begins. I tried on two macs, same issue.

Interestingly, I tried a CD walkman, and a cassette drck has sound sources and at their highest volume there is no distortion. But like I said with the analog mixer, and boombox, I do get it - and their not even at their highest levels. (Must be an ohm or impedence thing?? Or that these devices can put out enough power tgat exceeds the mac sound cards ability?)

There is double sound going to your headphones, but nowhere else. There is significant overload, but only in local monitoring. So once you know that, you can proceed with production and just ignore the gritty audio—until you get it fixed or a different machine.

Yes, I agree.

Thanks again for your time and other advice and info.