Audio crackles

[Lophophora]

Hi,

I have purchased and installed a brand new Focusrite Clarett 8Pre USB audio interface. Recently it started to produce crackling noises both when recording and playing. Before going further let me specify that I have a dedicated PC for my studio, that has been optimised for music production. Although it is not very recent, its specs should be more than enough to allow a smooth operation (Win 10, i7-4770K @3.5GHz, RAM 32 GB, 2x SSD).

I have tried various sample rates and buffer size combinations. The higher the buffer size, the less crackles I hear. However, I need to be able to work at 48 KHz with a total latency under 10ms, which I believe should be entirely manageable with the gear I have. I used a cheaper audio interface before (Roland Octa-Capture) and I never experienced any crackles, and had better latency values.

Any hint on what I should try in order to improve the situation?

[BertKoor]

I used a cheaper audio interface before (Roland Octa-Capture) and I never experienced any crackles, and had better latency values.

Any hint on what I should try in order to improve the situation?

Bingo, you found the culprit yourself. Focusrite hardware is top notch, but writing good drivers is not something they can pull off.

But maybe the advice from second post in this thread works for you. Otherwise you could swap it for a RME FireFace UC. A bit more expensive, but rock solid performance.

[lfm]

Isn't there ADAT on that Focusrite, at least there are such versions I believe.
I looked at OctaPre with ADAT converters built in, but the cheaper version, not Clarett - was it Scarlet.

What you need then is a reliable internal card for digital audio.
I would have a look at RME RayDat or AIO - and no problemo anymore.
Using a single ADAT on RayDat does not need wordclock. AIO has only on optical in and out, so that works. I use HDSP 9632, which is a PCI version of AIO like that with both addon board and 8 preamps over ADAT.

Focusrite make decent preamps, so no reason to swap unless you need more than 55dB gain for mikes you use. That is what kept me away.

[Kaine]

I have a dedicated PC for my studio, that has been optimised for music production. Although it is not very recent, its specs should be more than enough to allow a smooth operation (Win 10, i7-4770K @3.5GHz, RAM 32 GB, 2x SSD).

Specs are not really the focus here as you could pick up a top of the range system today and have it underperform exactly like this, all down to drivers running in the background. Please test it with latency monitor for 10 to 15 mins and check that it's passing.

http://www.resplendence.com/latencymon

[Lophophora]

Ok here's what I get after a few tests.

[lfm]

Seems rather high dpc latency to me.
I am constantly below 200us, but have RME internal card.

I believe WLAN adapters(WiFi) tend to increase dpc latency, and is recommended to be turned off.
To remedy that could be use cable to modem hub/router. No wireless network.

[BertKoor]

It says in the graph what the cause is: NVidia & DirectX Graphics Kernel. To cure it, put in another video card. If it's a laptop that's not really possible. If it's a desktop, then the question will be what video card to recommend. You don't need a gaming card, passive cooling should be fine. Only concern is to find one that behaves well.

[Kaine]

DPC checker (the first one posted) doesn't work properly under W10 (as it mentions before you download it) so you can discount that result.

Latency Monitor, the other one as Bert has pointed out is suggesting the Nvidia driver. I'm going to assume you've got the full driver package on there, so it's probably "Experience" ballsing everything up.

Download the latest version of the driver. Run it and select the option that doesn't install "Nvidia Experience". Also tick the "clean install" option and choose custom and feel free to remove any other component you think you might not need. You only really need the core driver, but you might want the HDMI driver (audio to monitor) or such for other activities.

Retest, but don't do it for more than 15 mins. Windows starts to do housekeeping after the 20 min mark of being left untouched, which doesn't normally happen if you have it under heavy load as you do when you recording/playing. If you leave it for more than that, it leaves us second guessing if it really is a wonky driver or just windows cleaning the SSD or checking for updates.

[Lophophora]

I believe WLAN adapters(WiFi) tend to increase dpc latency, and is recommended to be turned off.
To remedy that could be use cable to modem hub/router. No wireless network.

Already the case, there is no WiFi adapter in my desktop PC.

You don't need a gaming card, passive cooling should be fine. Only concern is to find one that behaves well.

I have a passive cooling card, which I chose to avoid to much noise coming from the computer. It never caused any latency problems for the past few years, is it possible that it suddenly becomes an issue?

[Lophophora]

Download the latest version of the driver. Run it and select the option that doesn't install "Nvidia Experience". Also tick the "clean install" option and choose custom and feel free to remove any other component you think you might not need. You only really need the core driver, but you might want the HDMI driver (audio to monitor) or such for other activities.

I did that, but I didn't find a way to avoid installing Experience, as it is the installer program itself. However I did get rid of everything but the core driver. I tested again 3 times for 10mn and I get the same result, or even worse. Any clue?

Anyway thanks, that was valuable information.

[Kaine]

https://imgur.com/a/hhrvR1X

On the current driver set, this is the first screen you see when you run it. If you're not seeing this screen, then you're more than 3 revisions out of date with the driver you're running.

You want the option I haven't ticked there, I should have bumped if off the default prior to taking the screen shot.

[Lophophora]

Ok I got rid of Experience and all unnecessary drivers. I now have only the core driver and it's up to date. Ran a few tests again, and the results are similar, maybe slightly better but still doesn't look great.

[Kaine]

Yeah, agreed. If you're up to date and it still points a that driver, it's time to try another card.

How about if you pull the card out and install the onboard GPU drivers as a test?

What model is your Nvidia card anyhow?

[Lophophora]

I have GeForce GT 630. Never caused any problems before, in a few years of usage.

In the meantime I have gone through Focusrite's recommandations again (https://support.focusrite.com/hc/en-gb/ ... Windows-10) and I realized I had overlooked one setting in the device manager (untick the save power option in the USB root hubs) so I did that, and I also realized that Windows changed some settings I had chosen (allow background apps), probably when updating. Turns out a new DPC test now give better results. Still not great, but acceptable: Latency Monitor says "Your system appears to be suitable for handling real-time audio without dropouts".

I will try removing the graphics card out in case I still get these annoying crackles.

[t3toooo]

You can try the adjustment i posted in this thread (which i've heard from "Kaine" the first time,btw.)

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