Odd metallic scraping noise when monitoring and recording guitar

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Level 1

8 points

Odd metallic scraping noise when monitoring and recording guitar

This is the oddest thing and I've been trying to suss it out for months with no luck mostly because I can't figure out how to describe it in a Google search without turning up results that have to do with noise reduction or distortion.

I'm hearing a strange, metallic scraping noise in Logic that happens under a couple of different scenarios, but here are the things that seem to all be happening when I hear it:

A guitar (any guitar) is plugged in and input monitoring is on.

The gain is turned up on the instrument and/or the channel to a reasonable level.

Either input on my Focusrite Scarlet 6i6 is being used.

It seems to happen when nothing is being played (no input) or when a chord is fading out.

It happens whether or not I'm using any amp simulators.

I have tried all the cables I own, every input available to me, every guitar and bass I own. I have even considered that it could be RF noise and have tried moving my laptop and setup off my desk which has metal legs. I still hear it.

And here's the kicker, I just recorded something in Audacity using the same setup and the noise was not present. I also brought that audio file into Logic and played it back. Again, the sound was not there.

So, this all leads me to believe that it is something screwy is happening with any audio that is being monitored or recorded going into Logic Pro X (I have version 10.4.7 running on a 2011 Macbook...I know, it's old...and I'm running Mac OS High Sierra version 10.13.6).

For fun, I just recorded a few strums with my guitar using Logic and uploaded it to YouTube, so you can all hear what I'm talking about:

https://youtu.be/L8IH6YSkI7I

Has anyone here experienced this? Any guesses as to what the issue might be? Any help would be appreciated. Just for full clarity and to reduce the amount of back and forth here are all the pertinent specs I can think of in one place:

Logic Pro X version 10.4.7

Macbook Pro 2011 running High Sierra version 10.13.6

2.7 GHz Intel Core i7

16 GB 1333 MHz DDR3 memory

Focusrite Scarlet 6i6 audio interface

Again, the problem does not occur in Audacity. So, that leads me to believe that Logic has to be the culprit. Thanks all!

MacBook Pro 13″, macOS 10.13

Posted on Aug 29, 2020 10:16 AM

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Answer 1

Pancenter

Level 6

14,788 points

Sep 5, 2020 2:53 PM in response to composertim

In Logic's Preferences/Audio under the General tab, do you have software monitoring enabled?

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Answer 2

composertim Author

Level 1

8 points

Sep 5, 2020 1:55 PM in response to Pancenter

So, if you're interested, I have another hint. A few times this week, I recorded something in Audacity and then imported the audio into Logic on an audio channel with one of my amp simulator plugins, and did not hear the noise. So that told me it was not the plugins.

Then, today, I tried recording into Logic without input monitoring selected for the track I was recording on. I wasn't able to hear my guitar playing through Logic as I played but what was interesting was when I listened back to the track with the plugin turned on, there was no noise.

So, I think I have a workaround at the very least and a hint at what might be causing the noise to occur. It only happens when input monitoring is turned on and it shows up on anything that is recorded with the input monitoring turned on. So maybe it's a processing issue. Maybe my machine can't handle processing the round trip of the audio through the plugins, while simultaneously recording. Just a hunch.

I had a friend install a SSD and a memory upgrade about five years ago and I've never had this problem before so maybe there's something else eating up a lot of processor space on my machine at the moment.

Thoughts?

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Answer 3

Pancenter

Level 6

14,788 points

Aug 29, 2020 11:37 AM in response to composertim

Are you using ANY plugins on the track, reverb compression....etc, anything at all.

Have you tried increasing the Logic Preferences/Audio I/O Buffer to the next larger size?

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Answer 4

Pancenter

Level 6

14,788 points

Aug 29, 2020 11:42 AM in response to Pancenter

One other thought.... Is the Scarlett 6i6 set to Internal Clock? It reminds of the noise when a digital clock is not synced with a second device. What Sample rate and bit depth are you recording at? Is the Scarlett set as both the Input and Output Device in Logic's preferences?

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Answer 5

Pancenter

Level 6

14,788 points

Aug 29, 2020 12:18 PM in response to composertim

Have you had this noise since day one with the 6i6? Have you looked online for a firmware update, Logic access devices differently than say Audacity. Did you install any software with the 6i6, there was a bogus low-latency patch that Focusrite pulled because of problems. Different USB Port? How old is the 6i6?

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Answer 6

Pancenter

Level 6

14,788 points

Aug 29, 2020 12:24 PM in response to composertim

One last, In the computer's System Preferences - Sound, select Built-In audio for both Input and Output. Separate the 6i6 from any other connection but Logic. Also Upgrade Logic to 10.4.8.

And go to the Upper left Logic Pro X Menu scroll the Preferences, select reset to defaults except key commands, immediately quit Logic and reboot the computer. You will need to reset several preferences.

That's about all I got.

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Answer 7

Pancenter

Level 6

14,788 points

Aug 29, 2020 12:05 PM in response to composertim

Ok that's project settings, go to the Audio tab and set the sample rate to 48kHz.

Now go to Logic's preferences and set it to look like this. w/6i6.

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Answer 8

Pancenter

Level 6

14,788 points

Aug 29, 2020 2:51 PM in response to composertim

Did you actually remove the TB-HDMI adapter, any software associated with that? Disable wireless in networking? Disable ethernet?

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Answer 9

composertim Author

Level 1

8 points

Aug 29, 2020 12:20 PM in response to composertim

I'm not sure if this is helpful, but I have a condenser mic always plugged into input 1 on the Scarlet 6i6 to do voice over auditions and I never ever have problems with this sound cropping up when I do those jobs. It's only when I have a 1/4" instrument cable plugged in through that same input that I get this noise.

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Answer 10

Pancenter

Level 6

14,788 points

Aug 29, 2020 12:30 PM in response to composertim

hmmmmmm.... I once got called in a paid session my hand touching the Strat's pick-guard was causing faint static scratching. That is helpful it points to the Scarlett's high impedence circuitry. Does the guitar have active circuitry?

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Answer 11

Pancenter

Level 6

14,788 points

Aug 29, 2020 2:23 PM in response to composertim

Catalina not recommended on an older machine. I'm using Sierra and Logic 10.4.4 one of best of all the recent Logic updates.

Best of luck, gave it a shot. Ummm you're not using an external monitor are you?

Any other peripherals hanging off the computer?

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Answer 12

Pancenter

Level 6

14,788 points

Aug 29, 2020 1:39 PM in response to composertim

Could it have begun after a MacOS update? Any cell microwave towers or 5g installations in the area, any continuous appliance running?

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Answer 13

composertim Author

Level 1

8 points

Aug 29, 2020 2:14 PM in response to Pancenter

Yes, in fact, just this afternoon I unplugged the input entirely and heard it with nothing plugged in, though fainter. It does seem to get louder proportionally with any gain increase.

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Answer 14

composertim Author

Level 1

8 points

Aug 29, 2020 11:39 AM in response to Pancenter

I am getting the noise with and without plugins, on a completely clean track, in a project I just opened. But just for comparison here's some random strums from Audacity:

https://youtu.be/3VTGn5N_t7s

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Answer 15

composertim Author

Level 1

8 points

Aug 29, 2020 11:47 AM in response to Pancenter

That's interesting. I hadn't thought of that. Here are my clock settings (I think this is where you look):

And I'm recording at 44.1 KHz (I'm not sure why, I usually record at 48 KHz, unless it defaulted back to that one of the last times I updated the program. Hmmmmm

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Odd metallic scraping noise when monitoring and recording guitar

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