Sync problem after file conversion

[Findlay]

I recently sent some files I'd recorded on my DP32-sd to a drummer friend to add some tracks. My Tascam recordings are 44k 16 bit. He sent back the drum tracks as 48k 24 bit WAV files as his system (not sure what it is) records at this rate. I couldn't load these files on the Tascam (I thought I might be able to) so had to convert them to 44k 16 bit using Audacity. These now load ok but they are slightly out of sync. They start off ok but quickly drift out of sync so much as to be intolerable after a few seconds. I'd be very grateful if anyone has ever encountered this and knows how to fix it - it is driving me crazy! Does it mean any file conversion is going to be out of sync?

 

[Mark Richards]

If the sync is off by the same amount once play starts (e.g., a consistent 6ms), then Mark In/Out;Edit/Move&Paste for each track should work. I don't recall if multiple tracks can be moved at the same time.

However, if the drift varies as the song progresses, the only way to fix the sync (either using a DAW or the portastudio) is manually as each section changes (same as above, but just one section of the song at a time, and for each track), and that can be very tedious.

Perhaps try this: Have your drummer export all the tracks (yours and his) from his system at 48/24, create a new song on your portastudio at 48/24, and then import.

EDIT
or try the TASCAM Hi-Res Editor. lnfo in my post #5 following.

 

[Findlay]

Thanks for this! The sync is off by about 300ms at the start but drifts as the song progresses. I've tried using a speed multiplier on the original tracks of around 0.998 in addition to the time shift but the drift varies as the song progresses. I will ask the drummer if he can do as you suggest, I hate to bother him in case he decides he doesn't want to work together again but ... I am surprised that this sort of thing happens, so used to digital being perfect!

 

[Arjan P]

If your drummer's system recorded at 48/16, the same system must have resampled your 44.1k tracks on the fly to be able to play them back. My guess is that's where things went wrong. Maybe ask him how he recorded and what his system was; perhaps knowing that can lead to other solutions.

 

[Mark Richards]

Findlay, download the TASCAM Hi-Res Editor from the TASCAM web site. It will quickly convert a 24/48 WAV file to 16/44.1

Described & linked in this Production Tips post.

 

[Findlay]

Thanks for the replies guys. Mark, I downloaded the Tascam Hi-Res Editor - thanks, it is great! But it hasn't helped here - I converted the 48/24 files to 44/16 and there is still the 285ms delay at the start and variable drift compared to my originals. It has made me realise it is vital to ask remote collaborators to work with your original format and avoid conversions at any stage. I have made all my DP32-sd recordings at 44/16 and find it perfectly adequate.

 

[shredd]

I have made all my DP32-sd recordings at 44/16 and find it perfectly adequate.

I've been following this with interest, as I've recently had well-document problems with "time" - different pieces of gear reckoning time with different degrees of accuracy, and thus not "sync"-ing properly, ruining many fine efforts.
Turns out a second is not a second, a beat or measure at xxxBPM is not the same, depending on what piece of gear is expressing it.

Shows how stewpyd I am - I thought time was time, and xxBPM would be the same no matter what.
NOT.

I also use 44/16 almost exclusively on my DP-32 - not that I don't appreciate the capacities of the higher settings, but because 99.98% of the listenings my recordings get (which is about 14, not counting myself!) are done on devices/equipment that couldn't POSSIBLY benefit from the higher resolutions.

AND - when it comes to collaborating remotely with others - I've had good results with exchanging tracks/song with others who are also using various Tascam gear, and working at 44/16...in most cases, the tracks have dropped in seamlessly, right down to being sync'd to the beat/measure settings (if they use it too).

Pretty kewl.

 

[Arjan P]

Ì would recommend using 24 bits instead of 16 at the recording stage. It simply gives you more headroom to work with. And I assume (but I'm not sure) that the Tascam machines would allow the use 24 and 16 bit files in the same project..

 

[shredd]

Tascam machines would allow the use 24 and 16 bit files in the same project

As the Resident Moron, I can't speak with any authority or certainty.
But on my 1st-gen DP-32, when I've tried to import 24b *.wav files into a project created at 16/44 - I forgot the error message, but it cannot be done.

 

[Mark Richards]

Findlay, I decided to perform a simple experiment, with the following result:
TEST 1 - DP-24 Session is 16/44.1; D.A.W. Session is 24/48
Original DP-24 track stem is 16/44.1

• 16/44.1 track stem imported to Mixbus D.A.W. 24/48 session
• 16/44.1 track stem exported from Mixbus D.A.W. at 24/48
• Use Hi-Res editor to downsample 24/48 track stem to 16/44.1
• Import downsampled 16/44.1 stem to DP-24 & compare with original DP-24's 16/44. stem

Result: No Sync Issues.
==============================================
TEST 2 - DP-24 session is 24/48; D.A.W. Session is 24/48; Test Hi-Res Editor Conversion.
Original DP-24 track stem is 24/48

• 24/48 track stem imported to Mixbus D.A.W. 24/48 session
• 24/48 track stem exported from Mixbus D.A.W. at 16/44.1
• Use Hi-Res editor to upsample 16/44.1 track stem to 24/48
• Import upsampled stem to DP-24 & compare with original DP-24's 24/48 stem

Result: No Sync Issues.
=============================================
And as shredd reported above, when importing to the DP-24/32/SD, the bit rates/sample rates of the stems must match the bit rate/sample rate of the DP-24 song session.

Absent any concrete information about how the drummer created his stems, I wouldn't want to speculate about the cause of a 285-300ms syncing/drifting issue. But having the drummer export all the stems (yours and his) should keep the entire project in sync for import to your portastudio as a new project (as I suggested previously).

At the beginning of the "Preparing Your Songs for Professional Mixing/Mastering" sticky thread there are a some suggestions that may also be useful with project collaborations.

The "Production Tips" sticky thread posts on "Using Track Sheets" may also have some pointers applicable when collaborating.

 

[-mjk-]

Thanks for the replies guys. Mark, I downloaded the Tascam Hi-Res Editor - thanks, it is great! But it hasn't helped here - I converted the 48/24 files to 44/16 and there is still the 285ms delay at the start and variable drift compared to my originals. It has made me realise it is vital to ask remote collaborators to work with your original format and avoid conversions at any stage. I have made all my DP32-sd recordings at 44/16 and find it perfectly adequate.

Even with the same recording resolution, if devices cannot share the same word clock then they all use their own internal clock. Although precision devices there definitely is drift. What I do is change the playback speed microscopically, per offending audio item. I literally have settings like -0.9575000. It can take time.

 

[-mjk-]

@shredd said:

AND - when it comes to collaborating remotely with others - I've had good results with exchanging tracks/song with others who are also using various Tascam gear, and working at 44/16...in most cases, the tracks have dropped in seamlessly, right down to being sync'd to the beat/measure settings (if they use it too).

I also have had no issues with tracks lining up - but my tracks have come from a single source, i.e. 1 person's DP machine. I line them up in Reaper and they play perfectly. I can then add my tracks and those work too (but that's different). But if the tracks come from 2 different sources, that can be an issue.

I did a YouTube video at a club and was using a 360 cam with mics. I also used my (non-Tascam) field recorder and I had to make some small adjustments.

 

[-mjk-]

Ì would recommend using 24 bits instead of 16 at the recording stage. It simply gives you more headroom to work with. And I assume (but I'm not sure) that the Tascam machines would allow the use 24 and 16 bit files in the same project..

I totally concur with the 24 bit recommendation, and your assumption is correct. No mixing of recording resolutions in a Song (DP's term for a project).

 

[-mjk-]

As the Resident Moron, I can't speak with any authority or certainty.
But on my 1st-gen DP-32, when I've tried to import 24b *.wav files into a project created at 16/44 - I forgot the error message, but it cannot be done.

Right. Can't mix resolutions.

 

[Findlay]

Thanks for all the comments guys, very much appreciated. This song has great sentimental value as we have been working on a score written by my late brother in 1978 that has never been heard or recorded before. My only option might be to re-take the guitars and vocals to the drums but I fear the guitarist might not like to re-take and my vocals, though full of errors are first takes and difficult to replicate with the same feel. Thanks for the tests Mark and your comments MJK, I have tried multiplication factors on the drums with up to 3 decimal places but no joy. If anyone has time on their hands I can send the files in case they can sync up.

Just wanted to add that I saw the thread where someone couldn't afford to buy Phil's manual and David Porter and others (and Phil) offered to buy it for him. What a fantastic thing to do. I have to thank David for answering my queries a few years ago before I bought a DP32. As a result of his help and you other guys I bought it and have recorded 180 songs I would never have attempted. Thanks so much,

 

[Arjan P]

Absent any concrete information about how the drummer created his stems, I wouldn't want to speculate about the cause of a 285-300ms syncing/drifting issue. But having the drummer export all the stems (yours and his) should keep the entire project in sync for import to your portastudio as a new project (as I suggested previously).

It should, but this is what I was hinting at previously: If the drummer used a DAW that is not so good at resampling the 44k audio on the fly in his 48k DAW project, it is possible that the drummer played with crooked timing from a lagging real time SRC. This should ofcourse be a DAW that accepts various sample rates in one project - they do exist but it's not very common. Cubase certainly does not. But as you say, @Mark Richards we simply don't have enough info about the drum recording.

@Findlay Do the other tracks have enough rhythmic info? It may be not so hard in Cubase to use 'elastic audio' (called Audio Warp actually) to fix the timing issue, but there must be a decent reference.

 

[-mjk-]

@Findlay I would think that among us that have commented on this thread, that we could solve this problem for you.

For example, there are audio-to-MIDI plugins that can create MIDI notes from the drum audio (depending on how they were recorded, of course) and the resultant MIDI notes can certainly be aligned to a tempo-mapped project. Plus if all that is wrong is that the drum performance is off, the drum part could be replaced with MIDI programming, manually. I recently did a complete drum replacement on a client mix using MIDI files. I manually tempo mapped the song, making adjustments to the tempo every 2 to 4 bars and the drums play with the rest of the tracks, perfectly because the tempo follows the normal inconstancies of human playing. As @Arjan P alluded to, as long as there is a good rhythmic reference source such as a guitar take that is reasonably consistent, that could be used to tempo map the song. The other performances could be stretched to follow the tempo map.

@Arjan P also touched on another point: not all conversion software is created equal. I like to do my conversions in RX 10 Advanced, even though Reaper auto converts upon import. As long as you have the original file the drummer gave you, you should try to use several other programs to do the resampling and see what effect that has on the timing.

Why don't you zip up the tracks and put them on a Google Drive and let us take a look and see what we can do?

 

[Arjan P]

Arjan P also touched on another point: not all conversion software is created equal. I like to do my conversions in RX 10 Advanced, even though Reaper auto converts upon import

No, actually I was referring to real time sample rate econversion, not the differences between off-line sample rate conversion software. Because flaky real time SRC would cause the drummer to go along with it, and so creating a flaky drum track.

And ofcourse there are huge quality differences in (off-line) sample rate converters, but I don't think any of them would get the basic math wrong.

 

[-mjk-]

@Arjan P oic what you mean now, thanks.

 

[Findlay]

Thanks again for your help guys. I was just about to zip up the tracks as MJK kindly suggested when the drummer came back with my synced tracks - he just had to shift them on his system, there was no drift. I would love to know exactly what caused this but will try to ask everyone I work with to stick to 44/16! I've posted a quick mix here in case anyone is interested in the song

https://we.tl/t-ujGjzslzn3

I could probably have sung it much better but went with first takes.

Thanks again.