parabola Posted May 13, 2011 Share Posted May 13, 2011 I am currently using Logic Pro 9 to edit 192k files that are transfers of analog masters. Basically what I am doing is taking the side A and B xfers and editing and exporting each song as it's own file. There are times where I need to insert silence at the tail of a file to create a spread between songs. When doing this I often will need to fade the tape hiss into the inserted silence. My issue is that when I merge the files the waveform gets this strange somewhat rectified look. The audio does not sound any different but I am concerned as to why Logic is giving me this strange looking waveform once the files are merged. I get the same exact result if I use "bounce in place". I have attached a picture that shows what is happening. On the top is the original file with the fade and the additional region that contains silence. The region on the bottom is the bounced file. You can see that the merged file has produced a waveform that looks very odd. Does anyone know why this might be happening? Here is what I am running: Logic Pro 9 iMac i3 4 GB RAM Working from internal Hard drive Editing 192k 24 bit multi-mono BWF Link to comment Share on other sites More sharing options...
David Nahmani Posted May 13, 2011 Share Posted May 13, 2011 My issue is that when I merge the files the waveform gets this strange somewhat rectified look. In the Arrange, Logic displays stereo waveforms by showing one side above the middle line, and the other below. Your picture shows a waveform that only has signal on one side of the stereo field. The audio does not sound any different but I am concerned as to why Logic is giving me this strange looking waveform once the files are merged. I get the same exact result if I use "bounce in place". Then maybe it's just a graphic waveform issue? What happens if you play the file in QuickLook (select it in the Finder and press the spacebar)? Link to comment Share on other sites More sharing options...
parabola Posted May 13, 2011 Author Share Posted May 13, 2011 David, Thanks for the reply. If played in Quicklook the audio sounds fine. So why is it that the merged region looks this way but the source file does not? When I merge the regions is Logic automatically creating a stereo interleaved file that is being displayed in the arrange window? If that's the case I understand why the region looks the way that it does. Is there a way that I can see both the left and right channel in the arrange window? I would prefer to do my editing in the score editor but I can only see a small portion of the region and I need a much broader view. Link to comment Share on other sites More sharing options...
Skink Posted March 18, 2013 Share Posted March 18, 2013 I'm seeing a similar issue to the one described above. I have a vocal track consisting of 4 separate regions (one for each verse of a song). I want to create a bounce that is identical to the original recording (no effects) but in one contiguous audio region so that I can send the vocal stem to a colleague as one file and preserve the timing relationship between the 4 segments. When I do the Bounce in Place (plug-ins disabled) the waveform of the new track looks different from the original. I can't detect any difference by listening but I'm concerned that I'm introducing some alteration of the original recording that I don't want. At first I thought that the original waveform was one-channel and the bounce is stereo, but that would mean that the original waveform should only be visible on one side of the centre line. In the screen shot the top track is the original and the bottom one is the Bounce in place. Link to comment Share on other sites More sharing options...
David Nahmani Posted March 18, 2013 Share Posted March 18, 2013 Skink, look at the format of your two audio files: it looks to me like the top waveform is a stereo file while the bottom one is a mono one. Link to comment Share on other sites More sharing options...
Skink Posted March 18, 2013 Share Posted March 18, 2013 Actually, it's the reverse (according to the bin). The top file is mono and the bottom one is stereo. The bottom track, file etc was generated automatically by the bounce in place process. The top one was generated by a recording from a single microphone (which is why it's mono). Link to comment Share on other sites More sharing options...
David Nahmani Posted March 18, 2013 Share Posted March 18, 2013 Actually, it's the reverse (according to the bin). The top file is mono and the bottom one is stereo. Please scroll a little bit to the left so we can see the beginning of the region, and take another screenshot. Link to comment Share on other sites More sharing options...
Skink Posted March 18, 2013 Share Posted March 18, 2013 Link to comment Share on other sites More sharing options...
David Nahmani Posted March 18, 2013 Share Posted March 18, 2013 Ok now zoom in a little closer onto the beginning of the waveforms (around bar 13) so we can see the waveform with a little more detail. Also, not sure you're taking your screenshots but if you Command-Shift-4-drag you can get a real size screen capture which is easier to see. Link to comment Share on other sites More sharing options...
Skink Posted March 18, 2013 Share Posted March 18, 2013 Sorry, this is my first post, so I haven't really got my screenshots figured out. I've been shrinking them so they fit on the page. Let's see if this one works. Link to comment Share on other sites More sharing options...
David Nahmani Posted March 18, 2013 Share Posted March 18, 2013 Oh ok so apparently the original file is a mono file while the bounced file is stereo but with the L and R being the same or similar. So if you want a mono bounce in place, click "Bounce Regions" then DEselect "include Volume/Pan automation". Link to comment Share on other sites More sharing options...
Skink Posted March 18, 2013 Share Posted March 18, 2013 When I did the bounce in place the "include Volume/Pan automation" was definitely DEselected. I just did it again to confirm. Incidentally, since the original track is mono, shouldn't the waveform by completely flat on one side of the center line? Link to comment Share on other sites More sharing options...
David Nahmani Posted March 18, 2013 Share Posted March 18, 2013 When I did the bounce in place the "include Volume/Pan automation" was definitely DEselected. I just did it again to confirm. And there are no plug-ins on the channel strips, like on your screenshot? If you have plug-ins, you have to, one by one, click them and choose "mono". Incidentally, since the original track is mono, shouldn't the waveform by completely flat on one side of the center line? No, what you describe would be a stereo recording where signal is only present on one of the two channels - which was the OP's issue. A mono recording displays a normal audio waveform that goes up and down around the center line. Link to comment Share on other sites More sharing options...
Skink Posted March 19, 2013 Share Posted March 19, 2013 And there are no plug-ins on the channel strips, like on your screenshot? If you have plug-ins, you have to, one by one, click them and choose "mono". If you look back at my first screen shot maybe you can see my plug-ins. I have Chan EQ, Compressor, Limiter and Ensemble. They are all disabled (in bypass mode). They were all set to mono except for Ensemble which was set to "Mono->Stereo". I just tried setting Ensemble to "Mono" and that resolved my problem. The resulting bounce in place now has an identical waveform to the original. Nice work! Thanks for solving the mystery. However, it does strike me as odd that with a plug-in disabled and the "Bypass Effect Plug-ins" option selected, you can still have a plug-in affecting the resulting audio file. Is there some logical reason for that or would you agree it's an unexpected result? Link to comment Share on other sites More sharing options...
David Nahmani Posted March 19, 2013 Share Posted March 19, 2013 Great! Glad to hear. Sorry I missed the bypassed plug-ins on your screenshot... trying to answer too many questions at the same time. And yes, you're right, a bypassed stereo plug-in still generates a stereo signal even though it doesn't otherwise process the original signal. Otherwise automating the bypass of a plug-in could result in a signal that's stereo, then mono, then stereo... that just wouldn't work. Link to comment Share on other sites More sharing options...
Skink Posted March 19, 2013 Share Posted March 19, 2013 Ok, that makes sense. I'm doing a lot of single-mic vocal recordings right now so it helps me a lot to understand this. Thanks for explaining and thanks for your help. Link to comment Share on other sites More sharing options...
David Nahmani Posted March 19, 2013 Share Posted March 19, 2013 Sure thing, glad to have helped. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.