Topic: Aligning WAVs w/Audacity

[Tony B]

Ok...I'm pretty much sick of beating my head against the wall, so....

I've got two seperate stereo WAVs from a show I recorded. The sources are as follows:

SBD>DA P1

  -AND-

SKM184>V2>JB3

Wondering how I can align these WAVs in Audacity to achieve a matrix mix. I've tried using the "Time Shift" function, and can get portions of the the WAVs to "line up" (i.e. remove the "reverb" sound from the mix), but further into the show, I'm still getting this reverb.

Basically, does anyone know how to align WAVs from two seperate sources? Would it have something to do with aligning via sector boundaries?

There's probably a pretty easy way to this, and I dig Audacity as a program, and I don't want to take a hammer to my harddrive on this, my first attempt at making a matrix mix.

Anyone?

Thanks and Peas

TB

[John Kelly]

This is a problem with shows recorded to different media.  I've seen it happen most often with DATs.  I've heard of two ways of dealing with it:  1) cut up one of the files into tracks and align each track individually, or 2) set the start and end file at the same point and stretch the shorter track to fit.

Good luck.

[Tony B]

THANKS John...You know, I was thinking about just cutting the two WAVs I have into tracks and algining them seperately....arrgh. I'll probably just do that. How weird!

Again, thanks

Tony B

[blu666z]

When I have matrixed a SBD and AUD I do the following in Cool Edit Pro.

1. Line up the files using peaks as close to the start as possible.
2.  Listen
3.  Once I can hear a drift(echo), I will stop and split where I can start hearing the difference.  Realign the SBD with the AUD.
4. Back to step 2

Its time consuming but can sound real nice once you're done.  Keep at it and also mess with the mix of levels of each source.

-Kevin

[Uncle Jimmy]

Hey,  that method is fine if you are listening through six feet of water using a rusty tin can as a headphone. Otherwise, line 'em up early in the mix and shorten (use the speed effect on an entire selection) or lengthen one to fit the other.

  If you want to get really creative, do that first, THEN lay over each individual track at the appropriate place and mix it all down when you are done.

   The main problem is that the playback is slightly slower or faster, and there is no way to tell which is right. I estimate that the drift is less than 1%, so the tone and pitch shouldn't be noticably different.... but you can check it before you mix it down.


Good luck, it really can be time consuming.

UJ

[blu666z]

Hey,  that method is fine if you are listening through six feet of water using a rusty tin can as a headphone. Otherwise, line 'em up early in the mix and shorten (use the speed effect on an entire selection) or lengthen one to fit the other.

  If you want to get really creative, do that first, THEN lay over each individual track at the appropriate place and mix it all down when you are done.

   The main problem is that the playback is slightly slower or faster, and there is no way to tell which is right. I estimate that the drift is less than 1%, so the tone and pitch shouldn't be noticably different.... but you can check it before you mix it down.


Good luck, it really can be time consuming.

UJ

He said he had tried that and it worked in spots but later on in the show the drift would come back.

-Kevin

[Uncle Jimmy]

"use the speed effect to shorten or lengthen the track".

[blu666z]

"I've tried using the "Time Shift" function, and can get portions of the the WAVs to "line up" (i.e. remove the "reverb" sound from the mix), but further into the show, I'm still getting this reverb. "

-Kevin

[Tony B]

Yep. That's correct. I've tried using the "Time Shift" function to line up the WAVs (i.e., eliminate the "drift"), and it would work for the portion I was listening to, but...further down the line, it would be off...big time.

So...just this morning, I normalized the AUD portion of my recording to 50%, then cut both the SBD and AUD versions into tracks via CDWave. Now, I'm going track by track and alighing the WAVs. It seems to be working, and sounds pretty damn good, actually. Now, I haven't tried playing back all the track (DAO on a CDR) to see how they all play together, but at this point I'm cautiously optimistic.

MANY thanks to y'all. I'd +T ya if I could, but...them's the breaks.

If anyone cares and wants to hear it, the show is by a New York-by-way-of-Minneapolis band called The Hold Steady. Great stuff, IMO.

Anyway...thanks again!
TB

[John Kelly]

"I've tried using the "Time Shift" function, and can get portions of the the WAVs to "line up" (i.e. remove the "reverb" sound from the mix), but further into the show, I'm still getting this reverb. "

-Kevin

He's talking about physically shrinking or stretching the track to make it the same length as the other track.  Not just shifting it...

(Same thing I suggested in my earlier post)

[Tony B]

Just so I can confuse myself further (and for my own edification), how do you do this in Audacity?

[John Kelly]

Dunno, never used Audacity to mix anything.  

[Uncle Jimmy]

OK kids,

   first off, blu666.... do you see what the difference is here? Cool.

   Next, I wanted to see if i was right, so I went home and checked it out. (I just so happened to have a show with two seperate sources of differing lengths.... go figure.)


    The problem you are having is due to the fact that your sources are of different lengths. Track A is shorter than track B, let's say. So you line them up at first, and as the show plays, the difference gets more and more noticable. As you see, the shift is not necessarily noticable over 3 or 4 minutes but might be over 30 or 40 min. So what you are doing with the individual trax is fine, but you will have to slightly overlap the trax at the seams so that all the individual Track B's will fint into the whole of the shorter track A.

  If you select the track (click in the box at the left of the waveform to highlight the entire track) and make sure playback is stopped, not paused, you can adjust the speed in the effects menu. This gets a little tricky, and i had to try it with two different compression percentages to get it right. (Make a duplicate of the track for eack different compression, then you can compare and keep only the ones you like.) It can help to find a kick drum or other specific spike in each of the two tracks so that you can jot down the points where they occur. Then, for the compressed track, find the same point and see how much it changed from the original. When you do it once, you will be able to say something like: At 0.4% compression, my beat moved 13 seconds. Then you can figure out how much more or less you want. (By the way... a negative percentage slows it down....)

If you do it this way then you wont have any overlapping to deal with (by cutting it out or leaving it as overlapped.. either way altering the original content).

IF IT SOUNDS MESSED UP... then maybe you want to go completely nuts (since I'm sure this mix is the only thing you have happening in your entire life) and shorten a little and then line up individually, thus decreasing but not eliminating overlap.


For the record, I am doing my project like this to get an audience recording (audio) to match the audio track from a video of the same performance. Why, you ask? because the film is synched with the original track, but it is crappy quality and i want to overlay the good audio while making it easy to re-insert it to the video. So I extract the audio from the camera, use it as a template for the right time duration of the show. I synch it up using the speed feature, mix the results making sure the resulting track is exactly the same length as the original camera audio, and then reassembling will be a breeze. (Right.)


*WHEW*

Peace out, gotta work sometime.

UJ

[leegeddy]

OK kids,

   first off, blu666.... do you see what the difference is here? Cool.

   Next, I wanted to see if i was right, so I went home and checked it out. (I just so happened to have a show with two seperate sources of differing lengths.... go figure.)


    The problem you are having is due to the fact that your sources are of different lengths. Track A is shorter than track B, let's say. So you line them up at first, and as the show plays, the difference gets more and more noticable. As you see, the shift is not necessarily noticable over 3 or 4 minutes but might be over 30 or 40 min. So what you are doing with the individual trax is fine, but you will have to slightly overlap the trax at the seams so that all the individual Track B's will fint into the whole of the shorter track A.

  If you select the track (click in the box at the left of the waveform to highlight the entire track) and make sure playback is stopped, not paused, you can adjust the speed in the effects menu. This gets a little tricky, and i had to try it with two different compression percentages to get it right. (Make a duplicate of the track for eack different compression, then you can compare and keep only the ones you like.) It can help to find a kick drum or other specific spike in each of the two tracks so that you can jot down the points where they occur. Then, for the compressed track, find the same point and see how much it changed from the original. When you do it once, you will be able to say something like: At 0.4% compression, my beat moved 13 seconds. Then you can figure out how much more or less you want. (By the way... a negative percentage slows it down....)

If you do it this way then you wont have any overlapping to deal with (by cutting it out or leaving it as overlapped.. either way altering the original content).

IF IT SOUNDS MESSED UP... then maybe you want to go completely nuts (since I'm sure this mix is the only thing you have happening in your entire life) and shorten a little and then line up individually, thus decreasing but not eliminating overlap.


For the record, I am doing my project like this to get an audience recording (audio) to match the audio track from a video of the same performance. Why, you ask? because the film is synched with the original track, but it is crappy quality and i want to overlay the good audio while making it easy to re-insert it to the video. So I extract the audio from the camera, use it as a template for the right time duration of the show. I synch it up using the speed feature, mix the results making sure the resulting track is exactly the same length as the original camera audio, and then reassembling will be a breeze. (Right.)


*WHEW*

Peace out, gotta work sometime.

UJ

UJ;

i don't disagree with your method in matrixing 2 (or more) audio sources, but there's a much simpler method that i stick with.  first, i'm using CEP (1.2a or 2.0).

in CEP's multi-track mode, the program will allow you to "splice" a waveform, (time) lock any portions of waveform, slide any waveform + or -.  there's no need to calculate time differential between asynchronous waves.   a note on "splicing".  CEP doesn't litterally cut the wave, it just allows to you splice and perform slide functions and saves that information in a Session file.  the working wave will always be intact, and all you do is save Sessions.  other multi-track programs like ProTools and SF all do the same thing.

as far as using CDWav to precut the big wav into smaller tracks.............. well, it could work, but sometimes i find that i need to perform slicing every song, or approx. every 5 minutes, sometimes in smaller increments depending what type of source material i'm working with.

i've litterally done dozens of sbd/aud matrix for 3 local tribute bands that asks me to tape them at their local gigs here in LA area.  i record both aud and sbd to my 2 dats (d100 and m1) and have yet to have 2 sources line up from the start.  i, too, look for very short transient peaks such as cymbals and sharp drum attacks for syncing points.

majority of the time, i like to keep the aud source higher in the mix and add the sbd for clarity in the vocals.  in this situation, i always splice the sbd and would splice during audience noise since that's the quietest part of the wave.  since the aud is more prominent in the mix, you can not hear the sbd splice at all.  few times i've done the opposite where i'd use the aud source to add ambiance to a good sbd. in this case, i'd splice the aud and sync it to the sbd.

i'll post some pictures from screen shots showing how i splice a wave and do the electric slide

btw, i just completed a sbd/aud matrix recording of Rush from '94.  it was a 2hr show and kept the sbd higher in the mix with the aud source adding demension.  i had to splice the aud source approximately 65 times (24 songs @ nearly 3 splices per song).  there's no way that i could have used time stretch calculations on all of these splices and it would have been impossible to accomplish.  this one was a bear due to the analog audience source.

anyways, i hope to post some screen shots the next time i do a matrix with some play by play commentary.

marc

[Uncle Jimmy]

OK... great. Someone who has actually done this many times. Thanks for the input.


Let's go over just a couple of details. First off, i am seeing no time shift in your method. No stretching or compressing. Cool.

Second, in the example you suggested, you said you were making as many as three cuts per song. OK, that's fine if you are splicing the track that is mixed lower, but in my case the track I need to alter is the "good" one and when i get them aligned, i will mix the "bad" one down to inaudible, so I don't think that method will be as desirable, as the cuts could become much more noticable without the other track to wash them out.

Moral of the story: your method seems very good for the situation you have, and when I am presented with the same situation I will take the advice to heart. Unfortunately, i have a different need which is replacing an audio track with a superior one, not matrixing them together. The reason it looks like a matrix is that i have to use the "bad" audio as a template for the time, since it corresponds exactly with the video.

"guidedbyvodka" - listen to leegeddy for your case, but know that my solution is out there, too.

This is a great thread, guys. Nice work, +T if I could.

J----