Nice to see you have had some input from the community on this subject. Here’s my ten cents worth…
If you look inside my DAW at any session from the last ten or so years, just about all of them have examples of using multiple compressors, EQ’s and filtering (LPF/HPF). Sometimes all on a single signal chain/channel.
To me, this is part of the world of modern audio production/mixing…
High Pass Filter/Filtering (HPF)…
So, as with the many tools available to us now, HPFs come in all sorts of flavours from fixed/static, variable, resonant to dynamic. They also come with different abilities and slopes:- 3, 6,12,18dB/octave etc.
Of course we can just use a single HPF on a channel or chain if we wish, but there are times when a single HPF is not enough…
Your chain for example, starts with a SM7B microphone with the HPF engaged. Fine, the SM7B has a fixed/static HPF set at 400Hz (apparently) with a very shallow roll off of -3dB/octave. If you are dealing with a deep/boomy voice the HPF will help deal with ‘reigning in’ excessive low and low mid frequencies. This helps balance the low stuff against the higher content of your audio and hopefully sound more balanced.
However, when I’m dealing with a weaker, thiner, quiet voice, then I would test the microphone without the HPF engaged and assess the results. The audio might benefit by not being processed with the HPF in some cases. Plus I can always process later in the DAW with the right tools as another option.
The next step in your chain uses a second HPF. This time it is set to a lower frequency (80Hz). Now the roll or cutoff per octave on your multitrack could be either 6dB,12dB,18dB/octave, etc (hard to tell here because of no information about it in your post). But this is fine because it is focused at a lower frequency than the first and therefore dealing with a different part of your audio spectrum. Is it needed?… Only you can answer that question by listening to the audio passing along your chain and by switching the filter in and out. Go with what sounds best for the type of production required.
The next stage in your chain has another HPF engaged. Also set to 80Hz. Now this one has me questioning ‘Why?’…
There are only four reasons that I can think of that this might be valid:-
To increase the cutoff/rolloff slope. Lets say that a 80Hz 12dB/octave HPF is in use but I want a steeper slope so why not use another set to the same frequency and the same rolloff and get a 24dB/octave curve instead. (Done that).
The HPF is actually in the ‘side-chain’ for the compressor. This changes how the compressor responds to the incoming audio. (Do this a lot of the time!).
When the audio signal passes between stage two and three in your list of processess it develops a problem frequency like an earth loop, ground noise, ac hum?. (Had this happen).
You have discovered the new ‘secret sauce’ to producing a certain type of vocal sound and everyone else is trying to figure out how you did it. (Thanks for sharing!)
Well this is normally different from the above because Mastering is about the final coat of fine finish/sheen to your audio and everything done normally at this stage is geared towards that goal. HPFs in this case are dealing with frequencies below 20Hz - 30Hz depending on requirements, (removing sub-sonics/creating more headroom, DC offsets).
If you are finding that your audio is sounding thin, lacking body or depth, HPFs can be one of the tools that can be incorrectly adjusted for the audio material. There are also others which can do just as much damage when incorrectly set as well. Compression and EQ can both be dangerous if you are not careful with them.
The key to all of this is being able to hear the difference accurately between each HPF being turned on or off in the chain. (The same could be said for everything else you do to your audio as well). This usually requires a good audio monitoring system/environment to help you identify what is happening and deal with any problems you may encounter. If you are out if the field and not in a controlled environment then try to use a really good pair of headphones to help you.