I thought digital-overs were bad?

Discussion in 'Mastering' started by sampsoniter, Oct 25, 2004.

  1. sampsoniter

    sampsoniter Guest

    ok, I always been told, and have read about how your master bus shouldn't go over 0db or you will have digital clipping, causing distortion or whatever, yet this doesn't seem to effect my tracks which are always pumping in the red, .......limiters ect all seem to just suck the life and quality out a track, and since my tracks seem to hit hard, sound right and have no distortiion the way they are, I couldn't bare to muffle them........so anyway, if digital overs are so bad, why do my tracks sound better with them, then without, and not have any negative effect my tracks?

    can somebody tell me
    what's up with all that?

  2. David French

    David French Well-Known Member

    Well, distortions lasting only a millisecond or two (44 or 88 consecutive samples at 0 dBFS) are usually inaudible. The tracks sound better to you probably due to the effect of the Fletcher-Munson equal loudness contours which shows that louder tracks will seem to have more bass and more highs. There is a mastering practice called 'shred' that involves purposely clipping the track by a couple of dB, then dropping it back down just under 0dBFS so that the meters won't show any overs. This doesn't seem like something a respectable ME would do, but we might be surprised.
  3. sampsoniter

    sampsoniter Guest

    thnx for responding david,

    ok , so is there any harm in leaving my overs since there is no audible distortion?.....why is it necessary to have your master peak at 0db, or is it?, and why?

    oh yes, I thought I'd kill 2 birds with one stone with this post if I may,
    I have read before that I should apply a highpass filter and cut everything below 60khz, because most majority of system's frequency range doesn't go below 60khz......as far as I know there are subs that pick up as low as 20khz, but I don't want to $*^t to distort on any sytem.........

    If you could clear any of these questions up for me,
    I would be, and am very gratefull.....
  4. David French

    David French Well-Known Member

    These questions are best answered by mastering engineers. I will say that I think you meant 'below 60Hz' and '20Hz' instead of 60 and 20 kHz. 20 kHz is about the highest frequency a person can hear and 60Khz is a musical 12th higher than that.
  5. Randyman...

    Randyman... Well-Known Member

    I'd assume you are getting the instentaneous "limiting effect" from clipping the D/A (or even the mix bus). This is acting like an instentaneous attack/release limiter, and likely only "clipping" a few samples per "over" (like David mentioned). You would be hard-pressed to find an actual dynamics processor that can perform to a sample-accurate threshold.

    I read a post here a while back, and someone claimed that the "big boys" even go as far as clipping the A/D's during tracking!!!???!!! I'm not sure how much water that holds, but I do know that I have had "larger" sounding drums with slight A/D clipping on kick and snare. I don't think I would be so bold on a lead VOX or bass guitar track.

    I would NOT cut 60Hz and below. Most descent stereos and Home-Theater systames will EASILY produce 40Hz and lower notes. If you highpass at 60Hz, your mix will likely sound like it is missing something (and it will be ;) ). The thing is, to watch out for "slop" and build up in the sub-120Hz range, and add appropriate HP filters on a "per-channel" basis to only leave the Kick Drum, Bass Guitar, and Keys/Special Effects in the "sub-bass" range. High-Pass all other tracks that you don't want to "feel" in your pants (Vox, Guitars, etc) :)

    FYI - Bass Guitar's Low "E" is around 42Hz (lower for 5-string low-B), and a kick drum can have a fundamental in the 30's! You CAN use a HP of around 50Hz on the kick drum if the Bass Guitar is carrying the lowest fundamentals, but leave something in the 40-50Hz range (usually bass OR kick, and keys).

  6. zemlin

    zemlin Well-Known Member

    It also depends on what software you're using. If working with 32 bit files in Audition, you can mixdown and have your mix go "over" without clipping (within the computer - playback will be clipped of you go over 0dB). You can normalize / limit the mixdown to bring the overs below 0dB.
  7. Michael Fossenkemper

    Michael Fossenkemper Distinguished past mastering moderator Well-Known Member

    Ok, here is the scoop. Clipping can sound good and even better than limiting on certain material. Depends on the clipper and the material. That being said, if you are in the mix stage, you are shooting yourself in the foot. IF a mastering engineer chooses to clip, he is doing it in a controlled environment and with the proper equipment and can taylor his tools to achieve the best results. If you are clipping your mixes, then you take away a lot of options that can be better performed during mastering. Eq'ing a clipped signal sounds like crap, eq'ing a non clipped signal and then clipping it sounds much much better.

    There are much better ways to get the sound you are looking for without clipping in the mix stage. Clipping is like crack, feels good at the moment, but over the long haul will wear on you. So now you know the sound you are going for, try and achieve that without clipping. the end results will be much better.
  8. Michael Fossenkemper

    Michael Fossenkemper Distinguished past mastering moderator Well-Known Member

    Another note on filtering below 60hz... don't do it. You will suck the life and the depth out. There is so much info below 60hz that adds too much to the music, even if the system can't reproduce it. Don't work towards the lowest common denominator. There has to be a payoff for those that invest their hard earned money to hear it.
  9. markwilder

    markwilder Guest

    Here's my 2 cents on overs. Ignore the meters and listen. I have found there are some converters (and other digital devices for that matter) that don't reach full character until you really push it. This may hold true for your system. What I do is listen in sum and difference for distortion and if I hear it, I then choose whether it's a positive effect or detracting from the music. I generally back off a hair, but some music benefits from the tension digital distortion adds. Much like how you might overdrive a guitar amp in some situations and not others.

  10. Ammitsboel

    Ammitsboel Member

    Yes, sad but true... I'm waiting for my new converters 8)
  11. Don Grossinger

    Don Grossinger Distinguished past mastering moderator Active Member

    I agree with Mark about converters. Listen, always listen.

    Do not filter below 60 hz. There's lots of useful stuff down there.
  12. soundfreely

    soundfreely Guest

    Interesting... Do I have to smoke crack to really understand what it is to clip a mix? :wink: Nice analogy!
  13. Michael Fossenkemper

    Michael Fossenkemper Distinguished past mastering moderator Well-Known Member

    Smoking crack helps when you're listening.
  14. EricK

    EricK Guest


    I need to take issue with this statement. Can you give me an example of where you have used digital distortion to your benefit. I have to be honest, I checked out your bio and I have not heard any of your work so I don't know if you are guilty of the same mastering practices as Vlado. Maybe you can give me some insight here, take for instance the Audioslave CD, there is obvious digital distorion on that release. The digital distortion on that disc causes so much tension I can barely stand to listen to it, and I really like the songs. The Red Hot Chili Peppers' "Californication" is another example of a disc I can barely listen to for the same reason.

    I don't know how closely you work with Mr. Meller, or how familiar you are with the 2 titles I mentioned above. I would really be interested in knowing if those recordings are already full of distortion by the time they reach the mastering stage, or if that distortion is a result of the mastering stage.

    I ask these questions with all due respect to both you, Mark, and Vlado.
  15. Ammitsboel

    Ammitsboel Member

    I don't think that Mark is talking about audible overs like on the RHCP album. There are different kind of overs... a 1microsecond over is an over but you may not be able to identify it as an over.
    And you will have lot's of those overs when moving the volumen towards 0db in a ADC input stage.
  16. radioliver

    radioliver Guest

    Can you pinpoint parts of songs on the Californication CD where there are lots of digital overs?? I haven't listened to that CD in a long time... I'd also be interested in knowing if it was at the tracking or mastering stage that it was produced. (y)
  17. markwilder

    markwilder Guest

    Sorry for the delay, I've been out on Daddy duty.

    I'm sorry you take exception to my comment. The CD which really changed my opinion of this view was Iggy Pop's Raw Power. In listening to it today, I might question the way I EQ'd it, but I think the level and distortion are perfect.

    I arrived at this totally by mistake, a long story I won't bore you with (or imbarass myself). But after I raised a stink, Iggy allowed me to cut it at 2 different levels. The first level was the hot level version, and the second was where I felt technically comfortable with it. After listening to the second version I felt really good about it, it sounded really nice. After I listened to the first version, I just wanted to kick someone's ass!!!

    This version was from a remix, and the distortion added a level of tension and angst that the original David Bowie mixes had, that the remixes did not. Now that's not to say the remixes were bad, they were great. But pushing the converters beyond their comfort zone added a "spice" on top that I couldn't get any other way. Period.

    For one moment, I took off my mastering hat and put on my music fan hat, and you know what, it worked. And Iggy showed me that (thank you Iggy).

    Now like I said before, I listen and listen hard. Never trust the meters. The ballistics are set differently on all of them, and overs are set for different amounts of consecutive overs. If I burn a master with a huge amount of overs, I'll write a note to the plant.

    That being said, you have to figure out what works for you as an engineer.

    Vlado Meller...As I mentioned in another thread here, I have great respect for Vlado and refuse to comment on his work on specific records.

    Mark Wilder

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