“Loud” = white-hot bits on spectrogram are the loudest. “bassy” = everything below 200Hz …
You’ll have to to increase the “window size” of the spectrogram from the default setting of 256 to 2048 to see detail in the bass frequencies …
If you have a lot of such thuds to remove you could try a multi-band compressor which can be set to ensure no bassy sounds go above user-defined volume threshold. Such a tool will process all of the audio in one go, i.e. it does not need to be applied individually to each instance. Paul-L’s De-Esser plugin can also be used as a De-Thumper if it is set to operate in the bass frequency range : 20Hz-200Hz , ( but Paul-L plugin is comparatively slow, even on two frequency bands ).