No NVIDIA EQ exists. Install Equalizer APO if you need to tweak sound over HDMI.
Here’s a concise, informative post you can use as-is or adapt for a forum, Reddit, or social media: NVIDIA High Definition Audio Equalizer – Where Is It?
If you're looking for an , here's the short answer: NVIDIA doesn't provide one.
The "NVIDIA High Definition Audio" driver is strictly for sending uncompressed multi-channel PCM, Dolby, or DTS audio over HDMI to your TV, monitor, or AV receiver. It has of its own.