I found this video, about the common mixing mistakes made with high pass filters, very interesting and enlightening. Would love to hear the thoughts of others on the subject. He talks about what he sees as the common misconception that you should high pass all of your tracks except the kick and the bass. Some people cut a bunch of the lows out, even up to 400-500Hz. Basically what I took home from it was:
 

• If you high pass your tracks too much, you lose a lot of the low end energy in your mix and the highs make it sound harsh and brittle. You're basically taking away the balls of the track. Try attenuating the lows (perhaps with a shelf) instead of cutting them. 
• Because filters introduce phase shifts into your signal, you're creating phase problems which build up in the mix between certain elements - especially if your're high passing multi-miked instruments separately. Therefore if you must high pass such instruments, high pass them together at the bus stage.
• The same goes for high passing tracks at every stage, for example high passing a direct guitar along with the amped version. And high passing the track, and then the bus etc. 
• Because of the resonant bump at the cutoff point of a pass filter, don't high pass all of your tracks at the same frequency. For instance, if you're cutting all of your tracks at 80Hz, you're going to get a build up around 80Hz. 

 
Anyway here it is: 
 

Interesting. 
 
I think it's very easy for some of us to end up doing things systematically. I know my own brain is always seeking patterns, even on a subconscious level, always looking for the way to do things. It's a constant battle to try and keep a fresh perspective. The way many of us learn - reading and watching tutorial instead of working with an experienced engineer - probably doesn't help either.
 
 
I think it's entirely possible that we sometimes overdo it. I know I've done it a few times. Lesson learned. But considering that a lot of us are dealing with sampled instruments and virtual synths and all sorts of DI boxes, it's absolutely not unlikely that a typical song would require a lot of high passing, because manufacturers seem to like to hype their products and exaggerate the low end, the high end and the stereo width. 
 
It's a range that's hard to get right because most of us work in rooms and with set ups which give us a warped perception of what's really going on.
 

Rain
Interesting. 
 
I think it's entirely possible that we sometimes overdo it. 
 

 
Agreed.  You should look and listen to what is going on before apply filters but definately need to A/B the results.  I have almost killed some good low end by apply a standard HPF when it wasn't really necessary.

and remember,
not all EQ plugins were created equal.

A few notes on the bullet-ed points.
 
1) If you high pass below the lowest fundamental, you will lose nothing.  Setting the filters too high will of course cause a lack of bass response.   It takes some analysis to determine the right point, and a good, full range, speaker system to confirm you are not doing more harm than good.  
2) Phase shifts only occur at the point of the affected signal, so you don't need to worry too much about the higher frequencies becoming out of phase, which is where and audible problems would occur.  Of course linear phase eq's were created to avoid any problems period.  
 
I use high pass filters often for high frequency instruments and sometimes on the master buss, cutting the energy below 30Hz where not much useful musical information occurs.  To use it on every track is overkill and rather pointless.  
 

This is a very useful and informative thread, thanks!

Linear-phase EQ
 
that's what i use
 
in conjunction with 'regular' eq's
 
 
like i said before..........
 
 
 
not equal

I really don't know anyone who says you should high-pass everything except the kick and bass, but here are a few more comments...

• The slope matters a lot. You might think you're below the range of an instrument, but the filter can affect higher frequencies.
• With samplers, transposing downward can produce subsonic artifacts that kill headroom. An HPF is salvation in this case.
• If DC offset is an issue, an HPF will help get rid of it.
• There are low-frequency components that are part of an instrument's sound. If you cut out too much, you'll lose them.
• An HPF is great for getting rid of room rumble but sometimes you want that (e.g., room mics with big drum sounds).