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bouncing problem????

Discussion in 'Recording' started by glenbo3000, Apr 23, 2008.

  1. glenbo3000

    glenbo3000 Guest

    Hi there,

    I'm editing and mixing sound using PT LE 6.4 alongside the ye olde' DIGI 001. All is well generally but if I bounce out a mix that I'm happy with I've noticed that if I import what I've just bounced out back in the highest peaks seem lower on the bounced out mix than what I've got in the edit. The regular/mid level stuff seems exact....

    Now, the highest peaks dont sound massively low but if I compare between them the edit will hit just below peaking but the same imported mix will be a couple of 'notches' lower....why is this? Am I doing anything wrong bouncing out? Does this mean that my mixes are lower than I think?

    I'm bouncing to disk in the simplest way - highlighting what I want then bouncing out as a mono summed wav.

    Any advice would be greatly appreciated!

  2. hueseph

    hueseph Well-Known Member

    Two questions:

    -Why are you bouncing to mono instead of stereo?
    -Do you have a limiter in the master bus?
  3. glenbo3000

    glenbo3000 Guest

    No, there is no limiter involved.

    Umm...I'm bouncing to mono as every track except one that I'm working with is mono. I guess I kinda made an assumption of better off mono in and mono out....

    Should I try bouncing and importing a stereo version and see what happens?

    Thanks for your interest hueseph!
  4. stealthy

    stealthy Guest

    im new to bouncing and PT, but heres what i do:

    A1-2 (Stereo L&R)
    Stereo Interleaved
    16 bit

    and i also compress/limit the on the master bus
  5. hueseph

    hueseph Well-Known Member

    I would think stereo would be better. Do you mix down to mono? Unless you have a specific reason to bounce down to mono, stereo would be the way to go. I'm guessing that there might be a phasing issue that's causing your signal to cancel out. It could be a lot of things. Can you post an example?
  6. glenbo3000

    glenbo3000 Guest

    Thanks Stealthy.

    Hueseph, no I'm not creating a mixdown via buses to mono, I'm simply highlighting a portion then bouncing to disk...should I do a mixdown within the edit before bouncing? Is this the usual process?

    Sorry if I sound a bit clueless!

    I read this -
    and it kinda states this is a better way to do things but doesnt actually say why.

    I'll happily post an example but cant until tomorrow

  7. hueseph

    hueseph Well-Known Member

    The article mentions "laying back to a new track". Essentially bouncing to a new track in your session. It's still in stereo though. You could bounce to two mono tracks that would be basically Left and right but it would be pointless since you would have to bounce to disk again. What you are essentially doing is routing your tracks to a stereo auxilliary and recording the playback onto those new tracks. The theory being that for some reason when you do a bounce to disk there are some other processes going on that affect the way the final mix sounds. I have noticed this in other DAWs. Specifically in Cubase where the mixdown is not in real time but I never noticed it in ProTools since the mix is in real time.
  8. taxman

    taxman Active Member

    In the ProTools book by Mike Collins he discusses an alternate way to move to disk to avoid certain bounce problems. I can't describe how to do it, as I have never gotten that far yet. Check out the book.


    Not sure how to send a URL either.
  9. BobRogers

    BobRogers Well-Known Member

    I'm still not clear on what you are comparing with the peaks on the bounced track. Since you have not mixed down to a new track, what are you using to determine the peaks on the mix before bouncing? The meters?

    [Update:] Oops, sorry. Read the article you linked to. Looks to me like the bounce part is irrelevant. If I understand correctly, you clicked on a single mono audio file - exported it to a .wav file - and then imported it back into PT.

    If that's the case, do an experiment. Invert one of the files and sum them together. See what the remnants are. Another question - what is the sample rate and bit depth of the recording and the exported file?
  10. glenbo3000

    glenbo3000 Guest

    Hueseph, I'm going to try the 'laying back to a new track' and then export region as file, as said in the article. I'll then import that back in and do another comaprison on the meters

    Thanks Taxman, I'll try and check that out.

    Bob, when you say 'invert one of the files and sum them together' how do I do this?

    The sample rate is 48. This is because the project is eventually intended for DVD and most pro equipment seems to deal with 48 and I didnt want to be messing about with sample rate converters.

    The bit depth is 16. I did it as 16 as all the original recording were at this bit depth and also its going to be quite a large project so disk space is premium.

    I know the Pro Tools meters are bit hit and miss, no increments etc, but its all I have to go by at the moment.
  11. BobRogers

    BobRogers Well-Known Member

    You can invert a track or a region by using the "Invert" function in "Audiosuite." Try it on a short passage where you can see the details of the wave form.

    I'm still not clear what you are doing. (Sorry if I'm being thick.) Are you bouncing by taking your mix, sending all tracks to a bus, sending that bus to a new track, recording that track, and then using the "export file" function (as described in the article). OR are you using the "bounce to disk" function?

    If the first, you can make a direct comparison between the single mix track and the exported/imported track. I wouldn't be completely shocked if there is a difference, but I'd like to know how big it is. If the second, I'm not too surprised that there is a discrepancy between what you observed on the meters and the expoted/imported track - two different types of visual displays driven by different programs.
  12. glenbo3000

    glenbo3000 Guest


    I did a comparison between a mono summed bounce, a stereo bounce, a stereo submix region export and also bouncing the submix.

    I reimported them and I'm sure the answer is the simplest, that it was just because I was going mono instead of stereo. The standard stereo bounce seems hit for hit the same on the meters.

    I feel slightly silly ALTHOUGH I must say I have learnt some stuff thanks to you guys and having a look at related articles.

    But it still leaves mean wondering what I would do to ensure quality if I needed to do a mono summed mix....maybe for use in 5.1 channel placement??? I think I'll remove the single stereo track from within my edit and see if the crushing is still evident.

    Thanks guys!
  13. hueseph

    hueseph Well-Known Member

    Dude. You are the smartest man in the world. I've made far worse mistakes than that on much more expensive gear.

    I don't know who it was that said "the first step towards wisdom is admitting that we know nothing to begin with".

    And so, no such thing as a stupid question.

    This would probably all come down to eq and phase. Which comes down to good mic placement.
  14. BobRogers

    BobRogers Well-Known Member

    Summing two halves of a stereo track isn't really and different than summing any other two tracks. There is always the possibility that they will interact in unexpected ways because of either addition or cancellation. The only way to ensure quality is to use your ears and learn to recognize problems and knowhow to fix them.
  15. Codemonkey

    Codemonkey Well-Known Member

    We need one of them motivational posters. The pic would be this thread, and the caption would have to be
    This guy has it. Go get your own.
  16. glenbo3000

    glenbo3000 Guest

    Thanks again,

    I've been on some other audio forums and they've been quite dry but recording.org has been really helpful.

    See you around!

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