Hi. I'm new to vMix (just started using version 20 as a trial) but have been using Wirecast for about 10 months. I've searched the forum but have not found an answer to this question.

I'm trying to bring in a remote guest via Zoom into vMix using Virtual Audio Cables for the audio and keep getting a crackling sound over that cable.

Here is my setup in vMix 20:
- In Settings > Audio Outputs: Master Output: Enabled; Headphones: Realtek High Definition Audio; Bus A: Line 1 (Virtual Audio Cable); Bus B: None; Default Bus for New Inputs: Master

- In Add Inputs > Audio Inputs: Audio Device: Line 2 Virtual Audio Cable; Audio Device: Blue Yeti USB Microphone

Here is my setup in Zoom:
- In Settings > Audio > Microphone: Line 1 (Virtual Audio Cable)
- In Settings > Speaker: Line 2 Virtual Audio Cable

My system configuration: Windows 10, i7-6700 quad core processor, 16 GB RAM, nVidia 750-TI graphics card. Windows indicates my Realtek sound card driver is up to date. In Wirecast, I've been doing screen captures of Zoom on a second monitor connected to this same PC and have not had any audio issues. (I've not had to use virtual audio cables though).

I saw somewhere on Facebook that the bitrates need to match among all audio devices in vMix. When I check the settings in the vMix Audio Mixer for each of my audio devices, I see that the Master Audio and Bus A indicate 48000 Hz 16 Bit 2 Channels, but my Blue Yeti Microphone and Audio Line 2 inputs indicate 48000 32 Bit Float 2 Channels. When I access my computer's Sound Panel, on the Playback Devices tab, for the Realtek High Definition Audio, I have tried both 16 Bit 48000 HZ and 16 Bit 44100 HZ but that doesn't seem to affect the outcome (crackling sound when testing the speaker button in Zoom after connecting the virtual audio cables). In my computer's Sound Panel, 48000 32 Bit Float 2 Channels is not an option for any Playback devices.

I am not streaming or recording. Just testing and getting the crackling sound when clicking the test button which plays a musical sound for the Zoom speaker after the cable is connected. (I don't get the crackling sound from Zoom speaker button inside Zoom when the cable is not connected and when the Realtek is selected instead).

Any suggestions on what I might be doing wrong?

Thanks.

PS: I know that vMix Call is a better option but I need to have a backup option for guests who for whatever reason don't have a WebRTC-compatible browser and can't install one or for example if there is a temporary problem with the vMix server, etc.

Yes it does. I’ve tried both settings with the Blue Yeti.

Thanks for the suggestion. I ran the performance monitor and my CPU was hovering between 10% and 20% so no issue there.

@mgrayeb have you made sure that your Virtual cable Playback and Recording devices in Windows have the same settings as everything else (e.g. 48 Khz, 16 bit, stereo)?

Yes, 48 Khz, 16 bit stereo. In this test, which I recorded and uploaded to YouTube, my only audio input is the Zoom meeting. I did not even have my Blue Yeti USB mic added as an input (although it too is set for 2 channel, 16 bit, 48000 Hz). P.S. Sorry for the poor video quality; a big storm blew out our internet service and I'm not sure if the video upload to YouTube from my phone was compressed additionally as a result of the extremely limited bandwidth.

vMix does not allow me to edit the field that shows the settings for those bit rates. I'm guessing the only place to change those is in the Windows Sound Manager -- but there wasn't a 32 bit option in there. So I don't know why vMix is showing one thing and Windows another.

Please see attached screen shot of the Virtual Audio Cables control panel. Should I be changing some of the settings in there? If so, any direction would be appreciated.

Thanks.

Thank you Michael for the suggestions. I changed the VAC audio bitdepth setting to up to 32 but the crackling persists.

I believe I need 4 virtual audio cables because I need to accomplish the following:
- Send mix-minus return program audio from vMix to Zoom
- Send audio from Zoom to vMix
- Send mix-minus return program audio from vMix to Skype
- Send audio from Skype to vMix

The reason I'm using both Skype and vMix (in addition to vMix Call) is because I want to have a backup option to vMix Call in case a guest can't come in that way for any reason and I know that Zoom is easier to access than Skype (don't have to have an account, video is better in my opinion, etc.). But I also want to have Skype so I can connect to Call In Studio to make it easy for the audience to call in and participate while a screener screens the calls.

Thanks for your note and your suggestions. My motherboard is not X99.

I looked into Voicemeeter Banana but it looks over my head from a technical standpoint. However, I did install the VB-Audio cable from that website (thank you and Michael Graves for that suggestion) and it worked like a charm -- no crackling!

So I reached out to the developer of the Virtual Audio Cables to ask if they have a sense of why I am experiencing crackling audio with their cables but not the VB-Audio cable in case that might provide a clue. (I'm wondering if there's some kind of conflict with the Realtek Sound Card, for example?).

If I could get 4 cables from VB-Audio it looks like my issue would be solved. Unfortunately, if I understand their site correctly, it looks like you can only get/install 2 additional virtual cables to use (beyond the initial trial cable for a combined total of 3).

Thanks again for your suggestions.

Given this level of routing sophistication, you really should be using VoiceMeeter Banana! It would be simpler than what you're doing now. It would provide the audio mix-minus arrangements, and act as a sub-mixer to vMix.

I use a dual-mix minus setup every week, involving bidirectional audio to/from:

- My headset
- A Google Hangout
- a SIP soft phone connected to a conference bridge

In this way we can have participants join via Hangout (V+A) or by telephone. In all cases it's fully interactive.

I know that I have enough capability left to add one more pathway. That suggests it would do exactly what you need.

Thank you for this! I downloaded VoiceMeeter Banana as you suggested, and then purchased two additional virtual audio cables from the same site. When I installed Voicemeeter Banana onto my system, the two virtual audio cables that come with that app were available for my use in my Windows Sound Manager.

Then, I purchased from the same website the two additional Virtual Audio Cables (donationware) and I downloaded the one free virtual audio cable, thereby giving me a total of 5 virtual audio cables (I currently only need 4 for my purposes). I don't even launch Voicemeeter Banana because I don't need that app; only the cables that come with it.

I routed two of the cables in Skype; and two of the cables in Zoom as follows:
- In vMix: the cable labeled "Voicemeeter Input VB-Audio Voicemeeter Vaio" is an audio output on Bus A
- In vMix: the cable labeled "VB-Audio Cable A" is an audio output on Bus B
- In Zoom, the Speaker output is connected to the cable labeled "Voicemeeter Aux Input (VB Audio Voicemeeter Aux)"
- In Zoom, the Microphone is connected to the cable labeled "Voicemeeter Output (VB-Audio Voicemeeter Vaio")

Then I added two audio inputs into vMix to bring in the same audio cables that I had assigned to in Zoom to "Speaker" and in Skype to "Speaker" respectively, and I've ensured that any audio inputs I want to send to the Zoom guests has the "A" button selected in the Audio Mixer for that element, and any audio input I want the Skype/Call In Studio guests to hear has the "B" button selected in the Audio Mixer for that element.

It looks like it works beautifully -- no crackling! Much appreciated. Thank you and everyone else who commented for your help and input and thanks to Kimberly and Martin at vMix for their great help as well!!