Synchronizing sound recorded at different locations

Hi All,

I use Audacity to record a podcast, but I have a problem.

Although I use Skype to talk to my interviewees I would
like to record the sound locally as I am convinced that
that will give me the best possible audio quality.
(I use a AKG C520 headset microphone and a Shure
X2U XLR to USB interface)

But the problem I have is to synchronize the different
files, I would like to ask for your input on this.

I am considering using the timer recording function
and simply setup all the recordings to start at the
same time, but I wounder if that will be exact
enough.

I can also use the time shift function to adjust the tracks,
and I wounder if it is exact enough.

I would also like to know it there is any best practise
that I should use when I do the recording to make it
easier to sync the different tracks in PP and if there
is any test that can tell me when the tracks are
sufficiently synced (other than just listening) ?

I would sincerely appreciate any help, Thank, Per

That’s how I would do it.
When recording on different machines, you may find that the synchronization gradually drifts out. If that happens, split one of the tracks (Edit menu) and if necessary delete a section of silence, then adjust one of the audio clips to bring it back into sync. You won’t need to be fantastically precise, just close enough for it to flow naturally. You may also want to edit out coughs, splutters and bloopers.

Thanks Steve I will try that!

I also found http://www.worldtimeserver.com/atomic-clock/
and the Atomic Clock Sync v3.0 I will use that to sync the
clocks on the recording computers and use the time record
function to get the best possible start!

I will report back when I got everything setup!

Thanks, Per.

use the time record function to get the best possible start!

If you’ve never done this before you can be remarkably sloppy and still have the cadence of the show work. You also need to know that the response to a question is going to happen one Skype® late and a conversation is going to happen two passes late. If you combine everything surgically perfectly, you’re going to get one of those news events that try to interview someone over a satellite. “Hello.” [awkward pause] “Hi, how are you? How are things in Nairobi” [awkward pause.]

So atomic accuracy, while generally a good thing, isn’t required as much as listening to the mixed show and see if it feels right. Did you find digitizers that will accept external clock? It could be said that sound cards that highly sophisticated are worried about multi-hour synchronization and a podcast may not need the atomic clock at all – just the really good sound card.

I have friends doing this on plain sound cards and it seems to work OK. One of the problems we haven’t licked is a little of the Skype leaking through to the show. No idea where that’s coming from.

Koz

Hi kozikowski,

Thanks for your input, I really appreciate it!

If you’ve never done this before you can be remarkably sloppy
It is my first time doing this, but sloppy isn’t really me :slight_smile:

You also need to know that the response to a question is
going to happen one Skype® late and a conversation is
going to happen two passes late. If you combine
everything surgically perfectly, you’re going to get one
of those news events that try to interview someone
over a satellite. “Hello.” [awkward pause] “Hi, how are you?
How are things in Nairobi” [awkward pause.]

That problem hasn’t been that bad, I also found allot of good
tips on getting the latency down in this video
http://www.digitalpodcast.com/podcastnews/2007/12/25/how-to-record-a-podcast-using-skype/

So atomic accuracy, while generally a good thing, isn’t
required as much as listening to the mixed show and
see if it feels right.
I manly use/like it for the simple installation so for me
the atomic accuracy is just a nice bonus!

Did you find digitizers that will accept external clock?
if you mean hardware I did find something that might be able
to do it it was a Sound Devices recorder
http://www.sounddevices.com/products/7.htm

One of the problems we haven’t licked is a little of the Skype
leaking through to the show. No idea where that’s coming from.
I have not had that problem, you see the hardware I use in my
original post…If I get it and solve it I will get back to you!

Thanks again, Per.

The way to synchronize the files I describe above

(I adjust the time on the recording computers,
and use a timed recording function in Audacity)

This works great for me, I can not notice any
synchronisation errors in the tests I have done
so far, I have no public test yet but when I do
I will add a link to a file recorded this way so
that you can check for yourself!

Thanks for all your help!

Per