Question / Help Can't use webcam w/ AT2020 + Scarlett 2i2

F

FrogSpawns

Member
As the title suggests, we recently just got two AT2020's and a scarlet 2i2 mixer.

We use logitech c920's as our webcam.

On OBS, if I have the webcams on, the mics start crackling, cutting out, and eventually just fail, as well as the webcams freezing. However, if I disable both webcams, the mics work perfect.

Any idea what's going on here?
 
Harold

Harold

Active Member
USB root hub overload probably. Tried moving the cameras around to different usb ports?
 
FerretBomb

FerretBomb

Active Member
Almost definitely, especially if you're running those 920s in 1080p mode. Each USB 2.0 host controller has a theoretical max bandwidth of 480mbps, but it's unlikely to ever see that.
A single c920 in 1080 mode can easily saturate the host controller it's connected to.

Easiest fix is to go into the Control Panel, into Device Manager, then use View->Devices by Connection. Then drill down until you find your USB host controllers, and expand them. Then make sure your webcams are each on their own host controller with nothing else on it (unplug them and plug them into a different port), and the Scarlett isn't on the same one as either of them or anything high throughput (external HDDs that you're recording to, for example).

Chances are good that the Scarlett is just being bandwidth choked out by the hungry hungry cameras.
 
F

FrogSpawns

Member
FerretBomb said:
Almost definitely, especially if you're running those 920s in 1080p mode. Each USB 2.0 host controller has a theoretical max bandwidth of 480mbps, but it's unlikely to ever see that.
A single c920 in 1080 mode can easily saturate the host controller it's connected to.

Easiest fix is to go into the Control Panel, into Device Manager, then use View->Devices by Connection. Then drill down until you find your USB host controllers, and expand them. Then make sure your webcams are each on their own host controller with nothing else on it (unplug them and plug them into a different port), and the Scarlett isn't on the same one as either of them or anything high throughput (external HDDs that you're recording to, for example).

Chances are good that the Scarlett is just being bandwidth choked out by the hungry hungry cameras.
Click to expand...

Ok so for all these tests, each webcam was on it's own USB section, as well as the scarlett being on it's own. (by being on it's own I mean not with the other webcam/mixer).

Without any webcams on, both mics sounded perfect and the audio was great.

With one webcam on, it started to crackle, and occasionally the stream would freeze.

With both on, nothing worked at all, and OBS froze.

How do I fix this? Would buying a powered USB HUB work?
 
FerretBomb

FerretBomb

Active Member
Were they on separate host controllers though? Not just different ports on the same host controller?

A USB hub (powered or not) does the opposite of what you need. It lets you plug more things into one controller, so you can split that (potential) 480mbps more ways.

What you'd want is a PCIe USB expansion card. The kind you used to get for computers that didn't have USB built in on the motherboard, or to add extra host ports (again, NOT a hub). Make sure it's USB 2.0 (c920s tend to have big problems with USB 3.0 ports, fixed by plugging them into USB 2.0 ports instead).
 
F

FrogSpawns

Member
FerretBomb said:
Were they on separate host controllers though? Not just different ports on the same host controller?

A USB hub (powered or not) does the opposite of what you need. It lets you plug more things into one controller, so you can split that (potential) 480mbps more ways.

What you'd want is a PCIe USB expansion card. The kind you used to get for computers that didn't have USB built in on the motherboard, or to add extra host ports (again, NOT a hub). Make sure it's USB 2.0 (c920s tend to have big problems with USB 3.0 ports, fixed by plugging them into USB 2.0 ports instead).
Click to expand...

Ah man. So what I did was lower each webcam to 720 instead of 1080. I can now get one webcam and everythings perfect. Two sends it over the edge though and freezes the mixer.

Sorry, how would I know if they were on the same host controller? I'm not sure if they were to be honest.
 
F

FrogSpawns

Member
This is what I'm working with. They are on the same controller, right?

67f999d71cf5cd526500e6d9e00dfbac.png

https://gyazo.com/67f999d71cf5cd526500e6d9e00dfbac
 
F

FrogSpawns

Member
I've been trying every port with different combos, and each time everything is fine when I start my stream until about 15-20 seconds in when either the mixer freezes, my keyboard goes out etc.
 
F

FrogSpawns

Member
Update:

Bought an internal PCIE USB expansion card, plugged the webcams in there, and the mixer into my regular PC USB ports.

The mixer STILL freezes on me, but the webcams are fine. What is going on here?
 
F

FrogSpawns

Member
Harold said:
Tried the webcams on the regular usb ports and the mixer on the expansion card as well?
Click to expand...
Harold said:
Tried the webcams on the regular usb ports and the mixer on the expansion card as well?
Click to expand...

Yes, same result.

However, now when I start the stream, I can have both webcams and the mic working fine, but when I turn on the capture card the mixer freezes. And our capture card is PCIE, not even USB.
 
F

FrogSpawns

Member
Except now our blue yeti mic is doing the same thing the mixer was. Just cutting out, and causing a delay. WHAT IS GOING ON LOL? This setup was fine before.
 
FerretBomb

FerretBomb

Active Member
Fathersongaming said:
This is what I'm working with. They are on the same controller, right?

67f999d71cf5cd526500e6d9e00dfbac.png

https://gyazo.com/67f999d71cf5cd526500e6d9e00dfbac
Click to expand...

See at the top where it says 'eXtensible Host Controller'? You should have multiple of those, normally. Your motherboard appears to be running a bunch of (virtual?) hubs off one USB 3.0 root, which could be causing problems (welcome to USB 3.0's notorious flakiness, and why I don't trust it, especially as a backbone). For contrast, here's a screenshot of my device manager:

jfQ2DhO.png


Each set of ports controlled by an independent host controller, ensuring that nothing steps on each other's bandwidth.

I'd say to try putting the Scarlett and Yeti on the same host controller, and the c920s on a different one, if you only have the PCIe USB expansion card as separate.

Far as the capture card freezing the mixer goes, I really have no idea. I'd probably look at drivers first (especially if the USB expansion card is now where the cap card was before, if reshuffling happened, and you didn't un/reinstall the drivers for the cap card after moving it).
After that, I'd check into the motherboard's manual. I know there are a few out there that have 'exclusive' slot pairs; if one is populated, the other can't be used. These are pretty rare though, and more often used on the low end (stuff like ECS and similar junk) to save on traces. Which is dumb, as you can plug a 1x card into a 16x slot just fine (though I guess it makes it look like the mobo is more capable/expandable than it really is?). Doubt it's this, but worth mentioning on the off chance.
 
F

FrogSpawns

Member
Last night we were able to get if working flawlessly with everything working together, by just raising the mixer off the ground and on to our table.

Today, we go to see if it's working, and the exact same problem happens again. Our audio freezes every 20-40 seconds. Loss for words.
 
F

FrogSpawns

Member
@FerretBomb

Yeah, maybe I can try putting the cap card back into it's original slot? Only reason I shuffled was because it was easier to plug in the USB card there, but I can get it the other way too.

Just at my wit's end here, nothing makes sense. How does everything work flawlessly last night, but then with the exact same setup, problems occur today.
 
You must log in or register to reply here.
Top