Topic: NJ3 .wav 44.1 recording jumps into 'chipmunk' mode while recording. Fixable?

[ljsurfer2002]

Damn, this might be the nail on this Nomad Jukebox 3 ... It has been finicky recently and hanging on the EAX boot screen ... sometimes it just won't turn off / hangs on that screen / etc.

I taped two sets last night. The first set was fine, i was able to stop the recording by pushing 'stop' then starting a new recording, just like i've  done a million times before. When I went to finish the recording and stop it, it hung after processing the recording and wouldn't turn off. I was able to get the files off of it after lots of re-starting and pestering and trying.

Now, when I listen to it, the first set was recorded fine, and the 2nd set recorded the full show, but for some reason about half way through it just decides to switch to 'chipmunk' setting and the rest of the show is recorded at super high speed. the waveforms look fine but the speed is way ramped up. I didn't change any settings, It was still recording the whole time as one long file. I only took it off of the 'hold' from time to time to check the levels ... the only thing I can think of is that the 9V in my batt box is kind of old, but that really shouldn't affect this at all, and is a nomad jukebox problem... 

Anyway, thoughts on how I can fix the file? I don't care about the nomad, I think this was it's last show. it is being retired to the drawer and i'm going to add rockbox to my old iriver iHP-120 since I hear good things about that ..

thanks!

p.s. here is the .wav of the transition to chipmunk ... it happens at time: 00:17.

http://www.megaupload.com/?d=C90C4BFV

[Roving Sign]

probably fixable - your recorder - for whatever reason - jumped sampling rates...since its playing fast - perhaps, assume it recorded at a sampling rate less than 44.1...might want to split the file at the "change" point - and try to change the header on the broken file part...

But, if it was a hassle getting the files off the recorder...might be HD trouble....maybe time for a new one...(or the H120!)

[sunjan]

i'm going to add rockbox to my old iriver iHP-120 since I hear good things about that ..

If you already own an Iriver, there's no reason not to rockbox it and use it instead. You get better gain levels and a much better feature set. You won't look back!

No idea what could have caused the change of frequency. Maybe a glitchy cable?
Agree with the previous post, your best bet is to split the file and change the header in Audacity or any other editor.

[ljsurfer2002]

I'm using Adobe Audition but I do have Sound Forge 6.0... This may sound stupid but I don't know how to 'change the header'. What do you mean? the sampling rate of the file? Just now in Audition I went "EDIT" then "Convert Sample Type" and then i'm at a screen where I have to pick "sample rate" from a Hz list (it is at 44100 like it should be) but it is chipmunkey .. I can pick "Bit Depth" (8, 16 or 32. it is at 16). "Dither" is hashed out and unpickable. and "Stereo" is picked (vs. 'mono'). there is also a slide bar from "Low" to "High Quality" and "150" is picked for "Pre / Post Filter"

picking "22050" didn't fix it. still fast paced. The lowest one (6000) didn't help either. still 'chipmunkey' but just rougher and lower pitch ...

any other ideas? Sucks to lose half of a concert, but yes, i'm going to install rockbox asap and use the iRiver instead. this nomad has served me well but is just too damn buggy / finicky now...

[rhinowing]

I'm using Adobe Audition but I do have Sound Forge 6.0... This may sound stupid but I don't know how to 'change the header'. What do you mean? the sampling rate of the file? Just now in Audition I went "EDIT" then "Convert Sample Type" and then i'm at a screen where I have to pick "sample rate" from a Hz list (it is at 44100 like it should be) but it is chipmunkey .. I can pick "Bit Depth" (8, 16 or 32. it is at 16). "Dither" is hashed out and unpickable. and "Stereo" is picked (vs. 'mono'). there is also a slide bar from "Low" to "High Quality" and "150" is picked for "Pre / Post Filter"

picking "22050" didn't fix it. still fast paced. The lowest one (6000) didn't help either. still 'chipmunkey' but just rougher and lower pitch ...

any other ideas? Sucks to lose half of a concert, but yes, i'm going to install rockbox asap and use the iRiver instead. this nomad has served me well but is just too damn buggy / finicky now...

try changing up instead of down

[ljsurfer2002]

didn't help .. hmmm I can get it to sort of sound like it should when I edit the "Adjust Sample Rate" value, but it reminds me "FYI: This just changes the soundcard playback rate. To resample the existing audio to a new sample rate, use Convert Sample Type". (Using convert sample type up or down, it stays chipmunky regadless. perhaps I need to try some new avenue. SO WEIRD.

[Roving Sign]

didn't help .. hmmm I can get it to sort of sound like it should when I edit the "Adjust Sample Rate" value, but it reminds me "FYI: This just changes the soundcard playback rate. To resample the existing audio to a new sample rate, use Convert Sample Type". (Using convert sample type up or down, it stays chipmunky regadless. perhaps I need to try some new avenue. SO WEIRD.

The header bascially tells the D>A converter: "Hello, Im a 44.1 file, please play these samples at 44.1"

I think if you just right click and select "properties" - it will tell you what the header says...

What happens is - sometimes the header will not match the actual sample rate.(for a variety of reasons)

Example - sometimes I record (using the jb3 digi-in) at 88.2 - but the jb3 still writes a 44.1 header - and the files playback SLOW...change the header, and bang, plays right speed...

This is NOT the same as resampling - when you change the header info, the samples stay the same...

Soundforge should let you see/edit the header also...

[Brian Skalinder]

Long answer:  This should lay out how to fix the header in a variety of apps:  http://taperssection.com/index.php/topic,80888.0.html
Short answer:  In Audition, Adjust Sample Rate is the feature you want.

Odd that it happened mid-stream.  I imagine it's possible the JB3 did, in fact, switch sampling rates mid-stream.  In this case, fixing the header still won't solve the problem because there are two different sample rates of data in a single file.  A single header sample rate will never match both sets of data.  So if all else fails, you might try finding the precise point at which it switches, split to two files (seamlessly, on a sector boundary, using CD-Wave or a properly configured editor), and then fix the header on both files independently.

[ljsurfer2002]

none of the above worked ... what actually did "work" was just splitting the file at the 'speed up point" and then making that a separate file. then just 'copy' the entire wave form of this new bad file, and then 'paste' the data into a new 44.1 / 16 bit .wav file and it worked fine! Only problem was that during the recording, there is still 'warbling' where it will go from regular speed, down to sloooow for about 2 seconds, then ramp up .. etc. really weird.

I figured it was the nail for that recorder. I have loaded rockbox and now need to learn how to use it, but I am on the right path now and not looking back to weird sample rate ghosts!

[Xontar]

Is it an instantaneous change to slow speed, then an instantaneous change back? Or does it gradually get slower for 2 seconds then ramp back up? If it's the former, Audacity's speed change plugin (or something similar in another program) should fix it up perfectly.

[ljsurfer2002]

it was a gradual slow down then back up over the course of a few seconds.

thanks all for the help! I actually video taped the whole show, so just patched the audio from the video source as the 2nd half. it isn't as good but it is better then distorted tempo / sounds! check it out here:

http://www.archive.org/details/scarletsymphony2009-04-20.at831.flac16

funny thing is, a few months later I used the same nomad to do a perfectly crisp SBD recording of what turned out to be the final show of a band I like. it got it all flawlessly! I have moved on to the rockbox iriver though. no more taking chances..