Question for Brad & Joe Re: LP Filtering

Discussion in 'Mastering' started by Bearclaw, Jan 29, 2002.

  1. Bearclaw

    Bearclaw Guest

    I've been present at a number of pro mastering sessions for major label commercial release projects, and each time always noticed the mastering engineer applying a Low pass filter around 20Khz. Is this a case of getting rid of frequencies you can't hear that are using up headroom, so you remove it to gain more overall volume on single mixes for radio?. Is there a specific reason for LP filtering a track for Radio?. If so, at what frequency do you Mastering Gods concider the upper limit of usefull Khz regarding Broadcast/Domestic systems and what db/octave would you apply the filter at this frequency.
    Many Thanks
    Bearclaw. :)
     
  2. brad

    brad Guest

    ....
     
  3. joe lambert

    joe lambert Distinguished Member

    Bearclaw,

    I think we had this same question a few weeks ago. So I'll try to give a more interesting answer this time. There are no rules. Some may use HPF all the time to make sure there is no low rumbly stuff to muddy up the song. The Duntech monitors we use are extremely accurate in the low end so I have the luxery to able to hear what is going on and if adjustments are needed. It depends on the mix, the song the and to some extent the format. There is a lot more low end (40hrz and lower) on many of the newer records, especially heavy rock. Finding the balance between the right amount of low end but to not get in the way of the mids and highs and still have the punch on smaller speakers is the trick. And whaterver works is the right thing to do!
     
  4. joe lambert

    joe lambert Distinguished Member

    Just to follow up on my last response:

    In my haste I thought you asked about HPfilters because I get that question regularly. As far as Low Pass Filters goes regardless if its vinyl or CD I would rarely use them. Remember that there is a lot of good stuff up there! Harmonics that put an air around the music. Vinyl has the ability to playback those extended high frequencies that I want to hear. Low end is the bigger problem with vinyl. So HPF are more common. As always it depends on each particular mix, but as a generall rule I don't use them unless there is a specific need for them.
     
  5. Bearclaw

    Bearclaw Guest

    Thanks for clearing that up guys. :D
     
  6. studio11

    studio11 Guest

    I find a really nice ^analog^ LPF helps smooth the harshness of digital recordings. I'll back it off as low as 16k. Analog recordings I rarely touch though. I think analog tape naturally diminishes SMOOTHLY on the top due to wear. I started doing this when a few clients preferred using their vinyl releases transferred to CD as opposed to their CD masters on their CD releases. Upon inspection I found a steep yet smooth roloff from 12k up. So, I've implemented this technique as somewhat of a digital cure-all. It doesn't always sound better on nice monitors, though it seems to carry much better through lesser systems.

    Dr.Spok ;)
     
  7. Don Grossinger

    Don Grossinger Distinguished past mastering moderator Active Member

    For vinyl cutting I usually filter at 12hZ & 16.3 KhZ. The high pass to prevent rumble, the low pass to protect the cutter head.

    For CD, I use filtering only for artistic purposes.
     

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