Crackle on recording Focusrite Scarlet 4i4 USBC

Hi folks,

I’m using Audacity 2.4.1. Windows 10 x64 Asus laptop

I am having some issues with my audio recording. There is a crackle which suddenly appeared a couple of weeks ago when everything had been working fine before. I broadcast on an internet radio station and I have a setup which is a little complicated so I’ll explain that:

I play music using Virtual DJ and broadcast to a shoutbox server. I control the software using a Denon MC3000 controller but the audio is routed through a focusrite scarlett and into an Allen and Heath Xone 62 external mixer. The output from that goes to my home amp/speakers and simultaneously looped back into the scarlet and back to my Asus laptop where it is broadcast and recorded by audacity. I also have a microphone Sure 58 which is connected to the xone 62 mixer.

So my home listening from amp/speakers and cueing on the mixer are clean with no crackle. The broadcast to the shoutcast server has no crackle but the audacity recording has the crackle.

I have attached an audio of the crackle and three screenshots from Audacity.

I have changed all of the cables to the scarlet, tried unplugging the mic, updating software etc. Because the issue is only with the recording I think its probably an audacity setting/issue but I’m stumped.

Hope you can help and thanks for your time.

Bob
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I think this is where you’re supposed to adjust Preferences > Devices > Latency > Buffer length. It’s in your illustrations.

Puzzled Puppy Look problems like this sometimes respond to System Splitting. Can you make a good recording if you’re not feeding the broadcast, for example? Keep peeling off services and connections until you can get the problem to change. Yes, it’s lovely if you can get the problem to go away, but if you can make the problem get worse, that can be majorly helpful.

If you’re hosting two (or more) different communications programs or services on your machine, you will, without fail, get smacked the first time one of them does a service update or change that interferes with everything else.

Does Audacity think it has access to your on-line storage such as Google Drive, etc? That’s not good news. Audacity doesn’t get along with those very well. Audacity depends on being able to work with a hard drive inches away, not a “fake” drive in another time zone at the end of a sloppy internet connection.

At the risk of playing Service Representative, have you restarted your Windows machine? Instead of a regular shutdown, use Shift+Shutdown > Wait a bit and then Start. That resets more things than regular shutdown.

Koz

I think this is where you’re supposed to adjust Preferences > Devices > Latency > Buffer length. It’s in your illustrations.

I’m not sure what to change the buffer length to. Any suggestions?

Puzzled Puppy Look problems like this sometimes respond to System Splitting. Can you make a good recording if you’re not feeding the broadcast, for example? Keep peeling off services and connections until you can get the problem to change. Yes, it’s lovely if you can get the problem to go away, but if you can make the problem get worse, that can be majorly helpful.

I’ve tried most things I can think of. I can’t get a good recording no matter what I do. I can’t seem to make it worse either…

If you’re hosting two (or more) different communications programs or services on your machine, you will, without fail, get smacked the first time one of them does a service update or change that interferes with everything else.

This is a possibility.

Does Audacity think it has access to your on-line storage such as Google Drive, etc? That’s not good news. Audacity doesn’t get along with those very well. Audacity depends on being able to work with a hard drive inches away, not a “fake” drive in another time zone at the end of a sloppy internet connection.

I save files to a dropbox linked folder. I have done that for ages though and not had an issue.

At the risk of playing Service Representative, have you restarted your Windows machine? Instead of a regular shutdown, use Shift+Shutdown > Wait a bit and then Start. That resets more things than regular shutdown.

Yes I’ve tried that.

If you’re hosting two (or more) different communications programs or services on your machine, you will, without fail, get smacked the first time one of them does a service update or change that interferes with everything else.

So what can I do to solve things if that’s the case?

Bumping this ( for the last time) and praying someone can help!

Have you tried adjusting the buffer length?
The default is 100 ms.
Try increasing it in steps of 10 or 20 ms and retest after each adjustment.
If that makes it worse, try decreasing down from 100.

Thanks Steve.

Sadly that doesn’t seem to improve things either going up or down.

:frowning:

Did it make it worse in either direction? It should at least make some difference.

I have gone from 30 to 300 and I can honestly tell no variation.

I’m trying to visualise this: You’ve got the MC3000 and the Xone 62 plugged into inputs on the Scarlet, and the output of the Scarlet into the Xone 62?
What is the “shoutbox server”? Is that sharing the input from the Scarlet?

MC3000 only connected to the laptop via usb to control Virtual DJ software. Not controlling audio.

Scarlet connected to laptop via usb. Two audio outputs from the back of the scarlet into my xone 62.

Audio from xone 62 to my home amp and speakers. This audio signal has no crackle.

Output from xone 62 is also taken to the front inputs of the scarlet and back to the laptop where it is sent to shoutcast server via virtual dj (sorry i said shoutbox by mistake before) for broadcast. It is also recorded by audacity and this is where the trouble lies.


If I take out virtual dj, the radio broadcast, MC3000 and just play a record on my decks and route that to the scarlet and into the pc then I get crackle on the audacity recording.

I have optimised my pc for recording audio as in this video https://support.focusrite.com/hc/en-gb/articles/207355205-Optimising-your-PC-for-Audio-on-Windows-10

I have changed all cables and tried new usb ports.

I have turned off internet, and antivirus software. Stopped unwanted startup processes. Reduced the amount on my hard drive.

I’m guessing that if you do this, you will still get the crackle. Please try it and say if that’s the case:

  1. Shut down the computer
  2. Disconnect all devices from the computer except for the Scarlet.
  3. Plug your microphone into the Scarlet.
  4. Boot up the computer
  5. Launch Audacity
  6. Make a test recording of your voice.

Yes still got the crackle.

Look in the Windows Sound control panel, in both the Recording and Playback tabs.
What is the “sample rate” for the Scarlet (Recording and Playback may be different).

Ok so I thought we were on to something there for a minute. When I went into the panel and my Denon Mc3000 was enabled both in playback and recording (as well as the scarlet). It wants to work at 48khz. I had a big issue recently with my radio station as our server needs to have 41khz files and not 48khz. I have to force Virtual dj to play at 41khz. I resolved that problem and so I thought that the difference may have been the issue here.

However I have now disabled the mc3000 in both playback and recording and set everything to 41khz. Still that crackling.
sound control panel.png

Try setting everything to 48 kHz, including the “Project Rate” in the lower left corner of the main Audacity window. Are you then able to record your voice without crackles?

I can record it but I can’t play it back…
48khz.png

Ok I’ve exported the test file as an mp3 and then played it using virtual DJ.

No crackles!

I don’t know why I can’t play the audio file in audacity at that sample rate?

I also have an issue now if setting everything to 48khz is going to be the solution because I need all the audio files to be 41khz for broadcast and saved recordings (these are broadcast later on an automated server).

Check that the Scarlet is still set to 48 kHz in the Windows Sound settings.


That’s the easy bit. Just set the “Project Rate” to 44100 before you export. The sample rate of exported files is taken from Audacity’s Project Rate.

“Project Rate” to 44100 before you export.

That’s the little window in the lower left, not the track rate.

Play the file after you export but before you send it.

It’s pretty unusual for systems to get stuck at 48000. That’s the video sample rate. 44100 is the audio CD rate and is almost universally assumed to be default for sound work. Does that ring any bells? Is there a video service or system anywhere in that pile?

Don’t forget to change it back before the next production run. Switching back and forth errors alone may be worth further efforts to find out what’s going on.

Koz