Four options at four different price points:
known to work well with the Wii; two options at different price points:
Second option is what I use, with an OG Component Cable. If you want to see samples, currently we're capturing at 720p, but it looks great at 1080p, with no noticeable latency.
I started with a Wii2HDMI, but the 3.5mm jack was fragile AF, and the sound through the HDMI was so hot anything below about 200-500hz sounded like farts. It made it an impossible option for long term streaming/recording.
The best choice would be something like this. It allows you to use component cables and doesn't have the shit quality that (most) Wii2HDMI does. The difference between component and composite is that component is a higher definition. Some people call component "RGB cables", which makes sense because they have an additional red plug as well as a green and blue one alongside the red and white for stereo audio. Composite just has stereo audio cables and a single yellow cable for video. Both are analog signals. Component supports up to 1080i (maybe 1080p but don't quote me on that), and composite only goes to 480i.
All the Wii2HDMI does is convert that analog signal to digital for the HDMI to read. Sure, the thing I linked does the exact same thing, but it's much better quality. I own one myself and it's far better quality than those Wii HDMI dongles. You'll get a very solid 480p image out of this and I think it looks spectacular. You don't need any fancy component cable in my opinion, but if you just have to go with the Nintendo ones then they're 30 bucks. I use an off-brand one and they haven't caused me any issues. Here is that, if you're interested.
Good luck!
You don't have a lot of information to go off of here, but I would bet that the issue is the "Wii 2 HDMI" device you use. It doesn't look like those type of devices have any proper power running though them.
If I needed to do what you are trying to accomplish, I would personally scrap the "Wii 2 HDMI" idea, go online, and get a "Component HD AV Cable" for the Wii. Then, get a "Component to HDMI Converter" as well.
Its more money and more work and more cables, but it is all well powered, will have a better quality signal both in audio and video at the end of the day. I'll link examples below.
For an idea on how that would all connect
Wii > Component Cable > Component Converter (powered) > HD 60s
I use these and they are perfect. https://www.amazon.com/Fosmon-Component-Cable-Definition-Nintendo/dp/B00CA8636K/ref=sr_1_3?crid=R9DKK7H8F8YK&keywords=wii+component+cable&qid=1637282788&sprefix=wii+comp%2Caps%2C181&sr=8-3
I bought the HD retrovision cables once to compare and couldn't tell a difference so I just sent those back.
For a universal cable the Gigaware ones have never let me down for years (both component and AV/svid).
Two options for component cables if you don't own the Nintendo brand already(No longer available), which is what I have so I am providing these links...
And here is the link to the converter I am using:
Easycel Component to HDMI Converter/Upscaler
You can view the capture video quality on our TY channel. Below I've provided an example of a pre-recorded (not streamed) release, so it will 100% reflect the quality of the setup.
https://www.youtube.com/watch?v=Fb1ygqLqvxk
All game footage is captured via Component -> Converter/Upscaler -> Razer Ripsaw capture.