WAV export shows up with a delay in other DAW

Installation & Configuration Linux
#1

Howdy folks!

I’ve been using Ardour for the last couple of years and finally decided to financially support the project since I have gotten so much from the software. Thank you Paul and all others who have contributed to it.

My band is recording our second full length album and I am using Ardour to do my guitar tracking. However, I am running into an issue.

I record my tracks, then I export them as WAV files and transfer the files via a site called www.wetransfer.com to my drummer who arranges all the tracks in Logic. The problem is that my tracks that I send to him are delayed behind the other tracks. I don’t have an exact number, but I would estimate between 15-30ms. When we listen to the mix, you can hear the playback on my tracks are delayed a split second. It is like the tracks don’t line up and mine are the only ones to have that problem.

When I export the files, I do notice that the DSP is maxed out at 100% although I am unsure if this is related to the problem.

We are pulling out our hair over here trying to figure out why my exported tracks are delayed in the playback compared to the other tracks.

If anyone has any ideas, advice or suggestions, I am very open, although I am not great when it comes to working my way around linux.

Here is what I am working with:

Ardour 3.5.143

AVLinux 6.0.2

No plugins running

firewire device running through FFADO

Jackd -
256 frames
44100 sample rate
2 periods/buffer
256 port max
2000 msec timeout

showing 11.6ms latency

Unfortunately Jackd is just starting up and immediately shutting down for some reason, but it was working fine with these setting before.

Computer -

Intel I5 3570k cpu
8gig ram
TI instruments firewire card

Thank you so much for any thoughts and feedback. I am very willing to try any and all ideas, but it would be helpful to consider me a newbie around linux.

Thank you so much!

-Dave

#2

The 100% DSP load issue is unrelated (ardour exports as fast as possible. “jack freewheeling”) 100% is expected.

First thing to check: is everything in sync on your machine before export?

Next step: re-import the exported file into your session. Does it line-up 100% ?
(check visually and/or invert the polarity of the imported ones (mixer phase invert button) the sound will cancel out if they’re 100% aligned)

If both are true: then either

(A) your session was not in sync with the other when you started recording
(B) the file is not imported at the correct position in the other DAW.

If not, well then there’s a bug in ardour or something specific to your session.

I just tried with a test-session and the exported file lines up exactly on re-import - but that’s ardour-git (3.5.4296). I cannot reproduce the problem.

Some more general information:

Ardour compensates for the latency (here: 11.6ms) that jack reports to ardour. There is always some small additional latency coming from the soundcard itself that jack does not know about, but can be told about.
This additional latency is usually very small (usually 1-2ms at most.) Ardour since version 3.5 has a “Measure Latency” tool (based on jack_delay) built in to measure and compensate for that. Menu > Window > Audio/Midi Setup.
see also http://manual.ardour.org/synchronization/latency-and-latency-compensation/

#3

what file format are you using for recording the tracks.

ive never looked into how ardour exports individual tracks, but my only thoughts are your not using broadcast waves, or some format that does not inlcude timecode on where the tracks line up, either that or the programs you are importing the waves either cant read the timecode as to where they should go or its not reading it right.

some programs only record export the exact length of the regions. Ive had this issue importing audacity exported waves into ardour. Audacity exports the waves as the length of the region and not the total timelength of the track and in turn when importing into ardour the tracks never line up. Rather than the expected behaviour that the exported tracks are all the same length.

#4

Thank you so much for your comments!

First of all, even though I’ve been using Ardour for more than 2 years, I’ve only scratched the surface with it and I’m still at the tip of the iceberg.

The idea to reimport the exported track is a really, really good idea! Also, about the inverting, I had no idea about that, so I will give that a try.

To veda-sticks - your comments on Audacity are somewhat ominous.

Here is how our process is going - our drummer takes his drum tracks ( in Logic Pro) and saves them all as an mp3, then sends the mp3 my way. I then take the mp3, convert it in Audacity to WAV, then import that WAV into Ardour. I then record my guitar to that drum track, and export that guitar tracks (muting all other tracks except for each one that I import, 1 at a time) into WAV files. I then send these WAV files back to my drummer, who sends his drum track and my guitar WAV file tracks to our other guitarist, who records in Logic Pro his guitar parts while playing along with our tracks, then sends his files back to our drummer who compiles everything.

The tracks are off just enough for me (who recorded the tracks) to notice, but probably not enough for our guitarist to notice. However, he has said that when he records, he turns the drums way down and records to my guitar. Still, when our drummer gets the files in Logic, my guitar tracks are lagging behind a few ms enough to make things sound off.

I would think that if I was sending out delayed tracks and our other guitarist was playing to those, than both guitars would be in sync and the drums would sound off in relation to all the guitars, but that isn’t happening. Right now, it is just my tracks. I got our guitarist to send me some files together and separately of everything on his end so we can know exactly how things sound when he receives them, which should help answer a few questions.

Still, these posts are super helpful and may help track down the issue. x42, thank you for your post - would you be able to tell me how I can check if everything is in sync on my end before export? Is it just the invert function?

I really appreciate this support. We’re about halfway through our album recording but have hit a dead stop until we can figure this thing out. It means a lot to me, thank you.

Note- this is not my recording PC that I am writing from, but I may have a chance to get in front of it later tonight and put some of these ideas into practice.

Thanks and I’ll report back ASAP!

#5

Hey guys,

Just tried re-importing my WAV file that was supposedly ‘off’, but it lines up perfectly with everything in the song. I tried the invert button, only it was a little confusing because one of the tracks was stereo and the other was mono so the sound kept getting muffled or un-muffled, but never totally went away between those tracks.

However, I zoomed in extremely close on the wavelengths, and everything lined up 100%.

I’m going to go through our other guitarist’s files to see what he is receiving from me and the drummer.

Will report back soon.

#6

I guess the other issue (I would have) with this process is that recording individual tracks, then compressing them to mp3, distributing them etc, and uncompressing them back to wav before (potentially) doing more processing (EQ, dynamics etc) is going to end up sounding awful.
If you mp3 a wav file, you throw away some of the audio content, if you uncompress back to wavs, that doesn’t get magically restored. This normally works (acceptably) because mp3 removes the stuff you can’t hear anyway (supposedly). But if you then EQ or process in other ways you can end up amplifying the artefacts of the original mp3 encoding / decoding, most of which do not sound good at all.
You might get away with it on drums, but if possible please compress to something lossless (or not at all) and save the mp3 for after the final mix - if you must.

#7

I think the drummer was finally mixing everything back together using his original WAV: the MP3 was just a guide track for adding the guitar.
The use of MP3 does raise a question though: the processing to make an MP3 adds delay, so maybe that delay is present in the MP3 file w.r.t. to whatever’s being used as a timing reference (the start of the file? not clear to me…) It might be worth having the drummer send a WAV file instead just as an experiment.

#8
The use of MP3 does raise a question though: the processing to make an MP3 adds delay, so maybe that delay is present in the MP3 file w.r.t. to whatever's being used as a timing reference (the start of the file? not clear to me...) It might be worth having the drummer send a WAV file instead just as an experiment
That's a good point, its certainly another 'variable' - worth investigating.
#9

Yep, that is correct, we are not using mp3s in any of the final mix, just using it to send files. But I don’t necessarily like them. I did request our drummer to send the original wav files and see how that compares to what I have.

Hopefully I will have a few more answers today as I go through the tracks our other guitarist sent to me.

Here is what he sent - 1x WAV of my guitar, his guitar, and the drum track. Basically, how things are showing up in his mix, and then 3x WAV files, each of those above tracks, separate.

If the composition WAV file has all 3 tracks in sync, it means that the issue is happening on our drummer’s end. If the tracks are off, then my guitar is probably arriving to him ‘off’ and that is the discrepancy. Having those 3 tracks separately will allow me to play around with them and compare them to my original tracks (re-importing) and see if there is a delay anywhere.

The mystery to me is how the two guitars can be ‘off’ on our drummer’s end if, when our other guitarist is tracking, he is turning down the drums and recording to my guitar.

We are testing all these theories on a specific song that was ‘off’ on our drummer’s end. My guitar was lagging behind the drum and other guitar tracks. When I asked our drummer to just send me the guitarist’s track and I will just stick that in ardour and see how it lined up, it was perfect.

So it is really hard to wrap my mind around all this. Our other guitarist is recording to my guitar, yet the tracks are off on our drummer’s end. If my track is delayed, I would think that would show up our guitarist’s end as well as our drummer’s, but it is physically impossible for him to be consistently play 10-20ms off from my guitar.

Will keep working on this today. Any other thoughts appreciated and I’ll keep you guys up to speed. Again, thank you so much for the help and support; I am very grateful.

#10

The problem is most likely mp3 encoding. Many mp3 encoders do not guarantee a Start-Sample offset. They shift things around a bit. I’ve seen up to 20ms offsets compared to wav (in my context video/soundtrack).

I suggest look into lossless compression flac (directly supported by ardour) or wavpack.