I use a Canon Legria (Vixia) HF G30 and have a Rode VideoMic Pro. I know the camera has a hiss on the audio which cannot be removed on the camera itself unless I had an external recorder or XLR box and mic instead, which I can't really afford the box and a mic or I'd be going that route.
I have set the camera to manual to adjust the levels of the audio as in most other settings, the level of the audio is too high and the hiss/background noise is quite high. I have lowered the volume of the audio in camera and turn on the Rode VideoMic Pro and normally don't use the high-pass filter (used to but prefer the native 40Hz-20kHz) switched it to +20db to compensate for lower audio volume and normalize it when editing.
On either settings the native 40Hz-20kHz or High-pass, there is always the hiss present in the audio.
I have tried recording 30 seconds of complete silence with the microphone on the camera and only hear the hiss sound. I tried using this in Audacity to isolate and remove the hiss from other recordings made with the camera and same mic, however, when I export the audio into Audacity and use the noise removal, it not only removes the hiss, but also some of the audio I don't want removed.
I first noticed this when I used the 30 second silent hiss recording, selected a part of the audio which had constant hiss, went to get noise profile, then opened a second Audacity and imported the audio from another recording (someone talking in front of the camera) with the camera and mic, went to get noise profile and isolate, when I clicked preview, I noticed some of talking was also being removed slightly if I removed the hiss this way, so that didn't work.
I normally use Sony Vagas Pro 12 to edit my videos, so if anyone knows how I could either remove or reduce greatly, the hiss noise using it (I have Fish Fillets plugin and messed around with Floorfish settings but can't get it how I like but using "exp: vox backgnd bleed" using default settings, does work to an extent but I can still pickup a hiss only not nearly as bad as it was) or using Audacity, without removing or reducing the quality of the other audio in the recordings, I would greatly appreciate it.