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Gear / Technical Help => Ask The Tapers => Topic started by: tchoub on April 05, 2006, 02:25:46 PM

Title: Strange delay in audience recording
Post by: tchoub on April 05, 2006, 02:25:46 PM

Hello,
I've recorded a concert a few weeks ago and have noticed a strange delay in the recording.
The following equipment has been used to record:
AKG 481 > sxm2 > sbm-1 > JB3 (44.1)
Here's a sample (http://mogwai.live.free.fr/sof_aud.mp3) of this recording.
The album version however sounds quicker: sample (http://mogwai.live.free.fr/sof_cd.mp3)

I suspect either the JB3 (slow hard disk ??) or the SBM-1 (stock version but the frequency selector may have been set between the 44.1 and 48 positions).

Does anyone has ever experienced something like this ?
Please, note that:
(i) another taper has correct speed on his recording
(ii) mics were placed only 5 meters away from stage.

Title: Re: Strange delay in audience recording
Post by: mmmatt on April 05, 2006, 02:54:54 PM

try renaming the file as a 16/48 file and then resample back down to 44.1

Matt

Title: Re: Strange delay in audience recording
Post by: Brian Skalinder on April 05, 2006, 02:56:05 PM

Sounds like a mismatch between the actual sample rate of the recording and the sample rate written to the WAV header.  Try changing the WAV header sample rate.  Note:  this is -not- the same as resampling.

Title: Re: Strange delay in audience recording
Post by: kcmoejoe on April 05, 2006, 02:59:20 PM

Sounds like you had the freq. selector switched to 48kHz and so whatever the SBM-1 is set to is what your JB3 will record at, and when you transfer it to your computer your capture card has to be set to the same freq. of 48kHz to match what it was recorded at. If not it will sound slower. This was my experience the first few times of recording at 48kHz and forgetting to set my sound card to match. Someone please step in and correct me if I'm wrong. hope this helps.

Title: Re: Strange delay in audience recording
Post by: mmmatt on April 05, 2006, 03:06:35 PM

Quote from: KCMoeJoe on April 05, 2006, 02:59:20 PM

Sounds like you had the freq. selector switched to 48kHz and so whatever the SBM-1 is set to is what your JB3 will record at, and when you transfer it to your computer your capture card has to be set to the same freq. of 48kHz to match what it was recorded at. If not it will sound slower. This was my experience the first few times of recording at 48kHz and forgetting to set my sound card to match. Someone please step in and correct me if I'm wrong. hope this helps.

jb3 is firewire/usb transfer.  I have done this with a ua5 before and I must have hit the switch after the jb3 was already running... the jb3 won't switch sample rates on the fly.

Matt

Title: Re: Strange delay in audience recording
Post by: tchoub on April 05, 2006, 04:08:58 PM

ahh, thanks for all the answers. The problem was due to a wrong wav header.
huge +T to you all !

For reference, here's the method that I used under CEP to avoiid the problem of the wav header:
(i) rename the .wav file to .raw file
(ii) in CEP: Open as > .raw > 48kHz > 48kHz
 

Title: Re: Strange delay in audience recording
Post by: Brian Skalinder on April 05, 2006, 04:15:54 PM

Glad it's sorted out.  :)

Quote from: tchoub on April 05, 2006, 04:08:58 PM

For reference, here's the method that I used under CEP to avoiid the problem of the wav header:
(i) rename the .wav file to .raw file
(ii) in CEP: Open as > .raw > 48kHz > 48kHz

For reference, another way to do it in CEP/Audition:

<1>  Edit | Adjust Sample Rate
<2>  Select desired Sample Rate
<3>  Save / Save As

Title: Re: Strange delay in audience recording
Post by: Chuck on April 05, 2006, 07:05:52 PM

I've found CDWav very useful for fixing problems like this as well.