Topic: need help syncing a sbd source + aud source...

[justink]

i've tried and tried with this one.  i've been successful before, but this one is killing me.

anyone willing to give it a shot?

please pm me and i'll send you a download link.  much appreciated.

[F.O.Bean]

How far were the mics from stage? Does it just need syncd or time stretched?

[justink]

How far were the mics from stage? Does it just need syncd or time stretched?

i was dfc in the sweet spot.  about 10-15 yards back. 

i can sync at the beginning, but the time drift at the last song is about 1.5 seconds off.  i've done the math and the shrink/stretch a million times but i just can't get it right for some reason... i figure fresh eyes might help.

[yousef]

The two occasions I've had this happen to me it turned out that one of the sources had a small glitch part way through that was throwing everything off downstream of it.

If this turns out not to be the case, I'd be chopping the board tape into individual songs and aligning each one separately - slightly more labour intensive in one sense but should hopefully mean that you don't need to do any time-stretching.

[macdaddy]

I'd be chopping the board tape into individual songs and aligning each one separately

this is the only way I know how to do it if the clocks weren't sync'd during recording...

[runonce]

We really need to get a good sticky post here - once and for all - so we start doing this right.

There is a thread that explains how to do the math, and fix sync issues using Audacity.

Sync issues are just an extreme example of playing a 44.1 file at 48khz - it will sound fast...like chipmunks.

Perhaps you have one file thats 44.0987 and another thats 44.1002 - (just for example) - sure they both are called "44.1" - but you have to make them truly match.

The math works - but I never did enough of it to explain that well - just followed the post.

Good point about glitchy sources - that might have some samples dropped. I had a bad toslink cable that kept throwing me out of sync...(and I was using clock synced A>Ds)

[acidjack]

If you are having an issue on the "doing the math" method but it's only the last track or few tracks that have an issue, I'd suggest maybe putting a few milliseconds of silence in the SBD somewhere in the middle/end, so you're in effect doing two separate aligns.  I'd still "do the math" to get it closer, THEN do that split.  With the AUD source being there, no listener will hear the silence in the SBD anyway (especially if it's at a point where the stage was silent) and it's less painful that re-doing the whole sync multiple times.

I did that for this one, and I think it sounds just fine...

http://archive.org/details/as2012-04-11.bowery_acidjack

[flipp]

We really need to get a good sticky post here - once and for all - so we start doing this right.

There is a thread that explains how to do the math, and fix sync issues using Audacity.

Sync issues are just an extreme example of playing a 44.1 file at 48khz - it will sound fast...like chipmunks.

Perhaps you have one file thats 44.0987 and another thats 44.1002 - (just for example) - sure they both are called "44.1" - but you have to make them truly match.

The math works - but I never did enough of it to explain that well - just followed the post.

Good point about glitchy sources - that might have some samples dropped. I had a bad toslink cable that kept throwing me out of sync...(and I was using clock synced A>Ds)

is this the one you're thinking of?  http://taperssection.com/index.php?topic=103031.msg1373822#msg1373822

I'd swear there was a pictorial tutorial posted but damned if I can find it now found it in the reference section - even though it is specifically for Wavelab5 some should be applicable to Audacity http://www.taperssection.com/reference/pdf/Wavelab5Matrix_MikeB.pdf

[runonce]

We really need to get a good sticky post here - once and for all - so we start doing this right.

There is a thread that explains how to do the math, and fix sync issues using Audacity.

Sync issues are just an extreme example of playing a 44.1 file at 48khz - it will sound fast...like chipmunks.

Perhaps you have one file thats 44.0987 and another thats 44.1002 - (just for example) - sure they both are called "44.1" - but you have to make them truly match.

The math works - but I never did enough of it to explain that well - just followed the post.

Good point about glitchy sources - that might have some samples dropped. I had a bad toslink cable that kept throwing me out of sync...(and I was using clock synced A>Ds)

is this the one you're thinking of?  http://taperssection.com/index.php?topic=103031.msg1373822#msg1373822

I'd swear there was a pictorial tutorial posted but damned if I can find it now found it in the reference section - even though it is specifically for Wavelab5 some should be applicable to Audacity http://www.taperssection.com/reference/pdf/Wavelab5Matrix_MikeB.pdf

Thanks flipp - I think that might it...the crucial part being

Go to VIEW>SET SELECTION FORMAT > SAMPLES (SNAP TO SAMPLES) so you can measure the length of your program in samples. Measure the total length from your sync points early in the file to the desired sync points late in the file. You will get different numbers for each file since they are probably not lined up perfectly due to slight variances in the clock chips of the two recorders. Make a note of each of these numbers. Subtract one from the other to find out the number of samples of drift at the end, and write this number down. Divide the length of the longer one by the length of the shorter source and you will get a number close to but greater than 1.0000000. Let's use an example where you have exactly one second of drift at the end of exactly one hour at 48KHz. The longer file is now 172,848,000 samples and the shorter one is 172,800,000 samples. Divide the long one by the short one and you will get 1.0002788. (If I am getting this right, then) this tells you that you that you need to speed change the longer file by -.02788%

[F.O.Bean]

I would align the SBD in tracks and guarantee its aligned

[bonghitwillie]

i am told that to do this right every track had to be recorded on the same recorder. that being said, i use 2-3 seperate recorders and have to add or delete frames (1/30 second) in between each song. i have also found that if you match things up perfectly sometimes there is phasing and one source needs to be off by a frame. this is why i am told the only way to do this is multi track recorders.