Time stretching on recording to PC

A

Andy Goodman

New member
Hi All -newbie here. I record several people locally on their PCs for a podcast. Everyone's recording is fine except one person. Her recording gets progressively more and more out of sync the longer the piece is. Does anyone have a clue why this is happening. I'm thinking, slow processor or crappy sound card?
 
The processor or sound card shouldn't be a factor. The most obvious would be a difference in the sample rate. If she is using 48K vs everyone else at 44.1K, you will have an 9% difference. If you plug a 48K file into a 44.1K project, you will get continual drift. Look at the properties of her file and see what the sample rate is compared to what you are using.
 
Sample rate settings could be the problem, but it would go out of sync pretty fast, and the pitch would be noticably off. It might just be a sample rate clock that's inaccurate.
 
Sample rates are all 44.1k

TalismanRich said:
The processor or sound card shouldn't be a factor. The most obvious would be a difference in the sample rate. If she is using 48K vs everyone else at 44.1K, you will have an 9% difference. If you plug a 48K file into a 44.1K project, you will get continual drift. Look at the properties of her file and see what the sample rate is compared to what you are using.
Click to expand...

Seems like the file is 44.1k like all the others - the file gets stretched out by a couple of seconds every hour. It's really weird
 
Andy Goodman said:
Hi All -newbie here. I record several people locally on their PCs for a podcast. Everyone's recording is fine except one person. Her recording gets progressively more and more out of sync the longer the piece is. Does anyone have a clue why this is happening. I'm thinking, slow processor or crappy sound card?
Click to expand...
How are you recording? Are you bringing your own interface & mic, or a USB mic, or do they each have their own? Recording with the same software and version? Same OS, etc?
 
Andy Goodman said:
everyone is recording with their own setup - PC, MAC, Audition, Audacity, Voice Recorder etc
Click to expand...
Well, then, what is the slipping one using?

And, is the time slippage noticeable on that system, or when you transfer the file to your computer?

I'd [WA] guess there's a bad hardware clock, or some weird sample rate, in their gear somewhere. Easy enough to test by trying a different setup there. It's the A/D part that will incorrectly slice too many pieces for the given time span, which on reassembly, in a different system or path with a correct clock, will cause it to stretch out.

P.S. (edit) If the device is set to 48kHz (sample rate), but the digital data received from the A/D bit is dumped directly into a file that says it's 44.1kHz, that's about an 8% difference, so you'd hear a big drift, like 5sec/minute. If that's the drift, then there's a difference between the recording software sample rate setting and the device, but it's not being picked up by the recording software and the project adjusted for it. Or they need to go into some device configuration software and change the interface/USB-mic sample rate to match what they set their recording software to.
 
Is it an mp3?

I've notice mp3s have time slippage issues, especially with spoken content with a lot of interspersed silence
 
You must log in or register to reply here.
Back
Top