Blue Cat's FreqAnalyst vs RME DigiCheck NG

Blue Cat's FreqAnalyst is a free plug-in for monitoring the spectral content of mono or stereo audio in real time. It displays spectrum, instant curve and peak curve views, with continuous changes rendered using smooth interpolation. Users can zoom the display, choose among sizes and set absolute or relative thresholds. The interface supports skins, transparency and zoom customization, while MIDI control, automation and MIDI Learn provide ways to control the plug-in. A preset manager is included, and users can copy and paste a plug-in state between instances. FreqAnalyst is not a standalone app: it requires a compatible audio host and is available in VST, VST3, AAX and Audio Unit formats for macOS and Windows. The stated operating systems are macOS 10.9 or newer and Windows Vista, 7, 8, 10 or 11. It supports up to two channels. The maker says processing stops when the input is silent, so it uses no CPU while idle.

RME DigiCheck NG has no write-up on Specifiction yet; its figures are above.