Log file (had to make new post):
[spoiler]13:08:47.594: CPU Name: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
13:08:47.594: CPU Speed: 4008MHz
13:08:47.594: Physical Cores: 4, Logical Cores: 8
13:08:47.594: Physical Memory: 16348MB Total, 7980MB Free
13:08:47.594: Windows Version: 10.0 Build 17134 (revision: 407; 64-bit)
13:08:47.594: Running as administrator: false
13:08:47.594: Aero is Enabled (Aero is always on for windows 8 and above)
13:08:47.594: Windows 10 Gaming Features:
13:08:47.594: Game DVR: On
13:08:47.596: Sec. Software Status:
13:08:47.597: Windows Defender Antivirus: enabled (AV)
13:08:47.597: Windows Firewall: enabled (FW)
13:08:47.598: Windows Defender Antivirus: enabled (ASW)
13:08:47.598: Browser Hardware Acceleration: true
13:08:47.598: Portable mode: false
13:08:47.673: OBS 22.0.2 (64-bit, windows)
13:08:47.673: ---------------------------------
13:08:47.674: ---------------------------------
13:08:47.674: audio settings reset:
13:08:47.674: samples per sec: 44100
13:08:47.674: speakers: 2
13:08:47.684: ---------------------------------
13:08:47.684: Initializing D3D11...
13:08:47.684: Available Video Adapters:
13:08:47.685: Adapter 1: NVIDIA GeForce GTX 1070
13:08:47.685: Dedicated VRAM: 4185915392
13:08:47.685: Shared VRAM: 4276367360
13:08:47.685: output 1: pos={0, 0}, size={1920, 1080}, attached=true
13:08:47.687: Loading up D3D11 on adapter NVIDIA GeForce GTX 1070 (0)
13:08:47.725: D3D11 loaded successfully, feature level used: 45056
13:08:48.330: ---------------------------------
13:08:48.330: video settings reset:
13:08:48.330: base resolution: 1920x1080
13:08:48.330: output resolution: 1280x720
13:08:48.330: downscale filter: Bicubic
13:08:48.330: fps: 60/1
13:08:48.330: format: NV12
13:08:48.330: YUV mode: 601/Partial
13:08:48.332: Audio monitoring device:
13:08:48.332: name: Default
13:08:48.332: id: default
13:08:48.332: ---------------------------------
13:08:48.390: Required module function 'obs_module_load' in module '../../obs-plugins/64bit/chrome_elf.dll' not found, loading of module failed
13:08:48.394: [CoreAudio encoder]: CoreAudio AAC encoder not installed on the system or couldn't be loaded
13:08:48.465: [AMF] AMF Test failed due to one or more errors.
13:08:48.465: Failed to initialize module 'enc-amf.dll'
13:08:48.573: Required module function 'obs_module_load' in module '../../obs-plugins/64bit/libcef.dll' not found, loading of module failed
13:08:48.587: LoadLibrary failed for '../../obs-plugins/64bit/libEGL.dll': The specified procedure could not be found.
13:08:48.587: (127)
13:08:48.587: Module '../../obs-plugins/64bit/libEGL.dll' not loaded
13:08:48.614: Required module function 'obs_module_load' in module '../../obs-plugins/64bit/libGLESv2.dll' not found, loading of module failed
13:08:48.647: [obs-browser]: Version 2.1.5
13:08:48.664: NVENC supported
13:08:48.813: Couldn't find VLC installation, VLC video source disabled
13:08:48.833: No blackmagic support
13:08:48.856: ---------------------------------
13:08:48.856: Loaded Modules:
13:08:48.856: win-wasapi.dll
13:08:48.856: win-mf.dll
13:08:48.856: win-dshow.dll
13:08:48.856: win-decklink.dll
13:08:48.856: win-capture.dll
13:08:48.856: vlc-video.dll
13:08:48.856: text-freetype2.dll
13:08:48.856: rtmp-services.dll
13:08:48.856: obs-x264.dll
13:08:48.856: obs-vst.dll
13:08:48.856: obs-transitions.dll
13:08:48.856: obs-text.dll
13:08:48.856: obs-qsv11.dll
13:08:48.856: obs-outputs.dll
13:08:48.856: obs-filters.dll
13:08:48.856: obs-ffmpeg.dll
13:08:48.856: obs-browser.dll
13:08:48.856: image-source.dll
13:08:48.856: frontend-tools.dll
13:08:48.856: enc-amf.dll
13:08:48.856: coreaudio-encoder.dll
13:08:48.856: ---------------------------------
13:08:48.856: ==== Startup complete ===============================================
13:08:48.861: All scene data cleared
13:08:48.861: ------------------------------------------------
13:08:48.920: WASAPI: Device 'Speakers (4- Logitech G430 Gaming Headset)' initialized
13:08:48.929: WASAPI: Device 'Microphone (Blue Snowball)' initialized
13:08:48.968: adding 46 milliseconds of audio buffering, total audio buffering is now 46 milliseconds
13:08:49.451: Switched to scene 'siege'
13:08:49.451: [game-capture: 'sieg'] attempting to hook process: RainbowSix.exe
13:08:49.455: ------------------------------------------------
13:08:49.455: Loaded scenes:
13:08:49.455: - scene 'TF2':
13:08:49.455: - source: 'tf2' (game_capture)
13:08:49.455: - source: 'facecam' (dshow_input)
13:08:49.455: - source: 'tf.tv' (image_source)
13:08:49.455: - scene 'siege':
13:08:49.455: - source: 'sieg' (game_capture)
13:08:49.455: - source: 'facecam' (dshow_input)
13:08:49.455: ------------------------------------------------
13:08:49.466: [game-capture: 'sieg'] shared texture capture successful
13:08:49.486: ---------------------------------
13:08:49.486: [DShow Device: 'facecam'] settings updated:
13:08:49.486: video device: Logitech Webcam Pro 9000
13:08:49.486: video path: \\?\usb#vid_046d&pid_0809&mi_00#7&2daf84a2&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\{bbefb6c7-2fc4-4139-bb8b-a58bba724083}
13:08:49.486: resolution: 640x480
13:08:49.486: fps: 30.00 (interval: 333333)
13:08:49.486: format: I420
13:08:49.511: CalculateFileHash: Failed to open file 'C:\Users\William\AppData\Roaming\obs-studio\updates\whatsnew.json':
[/spoiler]

Have you tried troubleshooting by individually deafening programs through the volume mixer?
Have you tried streaming to a different site like YT?
Have you tried streaming with a program that's not OBS?

[quote=Tob]Have you tried troubleshooting by individually deafening programs through the volume mixer?
Have you tried streaming to a different site like YT?
Have you tried streaming with a program that's not OBS?[/quote]
All good ideas, will edit this when I do all this

EDIT:
Did some more fiddling and apparently it's to do with having audio on 'low' quality instead of high/medium... really weird but setting it to high worked.