Dear High Pass Filter, You Suck!

This short post is in relation to the Free Mix Consultation that I offered last week.  I was overwhelmed with the response to be honest with you and had to spread out the consults over a few days.  I must say though I was really impressed with the quality of records I received.  Some better than other of course but on the whole, great stuff.

There was one thing though that seemed to be fairly common on the records I was hearing and that was in regards to the use, or over use, of the high pass filter.

Now I don’t think this post has to be unnecessarily long to get my point across and I think what I’m going to do is create a post next week with my “checklist” for mixing vocals in any genre.  Hopefully that can give you some ideas on how to approach the vocals in your next mix.

Less is More

I’ve already created a post on this very topic but it is particularly true when it comes to using a high pass filter on vocals.  Almost 100% of the time my high pass filter on vocals is set to less than 100hz and sometimes not set at all.  That’s really all you need to clean out some of that low rumble that creeps into the recording.

Control The Bottom End, Don’t Eliminate It

If the vocal is still sounding a bit deep in the low end and you feel like it still needs to be cleaned up than try and control that area instead of getting rid of it.  I can guarantee that a majority of the time it’s probably resonant frequencies and not “Mud” like most people think.

Because most recordings are done in home studios and done by people who aren’t engineers there tends to be a lot of problems – resonance is one of them.  It could be the room they are recording in, poor microphone technique or even just the wrong vocal chain for their voice.

A few things I like to do to control these low areas is to dip out a couple of dB’s with a peak filter, use a dynamic EQ like the Waves Audio C1-sc, or a multiband compressor.  Any one of those will help in controlling the problem areas and help to keep the vocal as natural as possible.

The one thing I would say though is try not to become to obsessed about this because there will be times when the vocal is just too difficult to maintain and you have to settle.  You maybe settle with a little harshness or a little boomyness but just do your best to choose the best option in the moment.

An example would be if your track has a lot of low end instruments then the better sacrifice would probably be to leave the vocal slightly harsh.

Don’t High Pass Everything!

The whole “High Pass Everything” analogy is so overrated.  I would say that a better idea is to high pass the things the absolutely need it and then leave everything else alone.  Sometimes a sound just needs a little shelf cut of a few dB’s to lower the bass volume enough so that it can fit comfortably in the mix.

Defaulting to the high pass filter can often be the easy way out.  My suggestion is to really listen to the sounds you are given and find that balance.  Pull out the EQ when you need it and be as subtle as you possibly can.  Massage the track as you go along, little by little.

The Challenge

I challenge you on the next mix to NOT USE HIGH PASS FILTERS.  This might seem absurd and of course it is but try it out or do it for as long as you possibly can.  If you can get over the comfort of using it, you will be amazed that the high pass filter is actually not needed as much as you think.

It’s incredible how many other ideas and techniques you will think of to make the mix work.  Plus your mix will start to sound more natural and full.

  • Your article here is spot on. I found this out when mixing and then trying out the tracks in my car. My low end was missing in some key areas. I found I was high passing too many items. Correcting that made all the difference.

  • jdonyc

    “My rule is, if you can’t hear it, you don’t need it. Turn on the lowest band of the EQ and make it a high-pass filter, or use the high-pass filter if it operates independently. Start with the frequency all the way down. Leave all of the tracks playing, with the acoustic guitar in the mix. Start raising the frequency of the high-pass filter slowly until you can hear a change in the sound of the low end of the acoustic guitar. Look at the frequency on the high-pass filter. Now reduce the frequency by about 15 percent. That means if the frequency reads 200Hz, then move it down 30Hz to about 170Hz. If you do this to each of the mid-range instruments, it will clean up the muddiness problem in your mix.”
    -Roger Nichols (one of the greatest mixing engineers ever)

  • Charlie Sandewo

    I’m a trainee sound engineer at my church, when i’m not using the high pass filter for the bass it would make like everything trembles, can i do something about it even without using hpf?

    • Shane Foster

      Turn the sub amp down.

    • Shane Foster

      Try turning down the sub amp.

  • EvilDragon

    One thing that is very important to note is if you default to “highpass everything” and you have some multitracked drum tracks, you will fuck up the phase on them, which is going to produce some unwanted cancellations in the signal.

    Remember that filters don’t alter frequencies only – they alter the phase as well! Unless you use linear phase filter, of course, but they have their own share of caveats (processing latency which demands PDC, and pre-ringing of course)…

    I would agree with “highpass only stuff that REALLY needs it, leave the rest alone”, and even then, I’d rather try and solve the issue with a peak EQ instead of a full-blown highpass, since that’s gonna fuck up the phase less than highpass would.

  • ilias boufidis

    hey justin, i appreciate your posts and articles even if i don’t always agree. i think you could have elaborated more on how important the hi-pass slope is. how different degrees of filtering might make or brake a perceived as full range channel. personally i love my 1st order 6dbs, they help in certain situations without being flashy 🙂

  • Rita Delray

    Very interesting, Justin. I just went through something just like what you’re talking about. One of the songs by a band I recently had in my studio had a strange, but almost unnoticeable sound that can best be described and a l-o-w bumping sound. At first, none of the musicians could hear it, but after isolating it and revving up the volume they finally heard it. After several attempts at reducing it, and almost giving up and re-recording the two tracks that were the culprits, I wound up using a linear EQ (LP64_EQ). I dumped everything below 135 Hz (Freq) — 0.3 dB (Gain) — 2.0 Q’s (Q). It solved the problem on both tracks. It cleaned up the vocal track and gave the offending acoustic guitar a cleaner sound, albeit, a bit more twangy. By the way, I was using the ‘GRID’ selection.

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