CD Walkman playing fast?

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Sotonfan

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Our group recorded several tracks live, running into a CD burner. Our bass player was running the mixer, and we needed to go back and record his part afterwards. We don't have a multi-track recorder, so I planned to get the bass track on a second CD and then match it up with the earlier recording, using Cakewalk.

I took the first CD we had burned and put it in a CD walkman, then played it back through the monitor while recording the bass player onto the CD burner. Then I took the new recording of the bass part and put it on my computer, along with the original recording. But for some reason, the bass part didn't match up: it was slightly out of sync with the other recording - almost as if the recording he was playing with was going too fast?!? I know a tape can vary in speed, but I assumed that a CD would be rock solid. I'm really confused here. Is there something I'm missing? Or can a Walkman speed up?
 
We're the tracks recorded at different sample rates?

That's the only thing i can think of. Normally CD's are 44.1K, but if one track was recorded higher or lower than that, they might play back at a different speed when burned.

Was there anytime when you transferred the tracks to your computer where the sample rate on one of them might have been altered?
 
I don't think that was it.......if it was recorded at a different sample rate......I believe the player simply wouldn't play it at all.
 
Digital recorders have a clock that determines the rate they record at. Cheap recorders have cheaper clocks and are not as rock solid as a dedicated word clock that costs as much as many recorders. When you compare the recordings done with a cheap clock they will indeed drift over time. Once you have both recordings into the computer you might be able to break up the bass track and align the individual parts with the rest of the song.

The only way to reliably sync up recordings done in seperate passes on a single track recorder is to use Time Code or midi sync so the track has an absolute time reference and your walkman probably does not have that.
 
Yes. It seems as if your tracks were recorded at different sample rates. :cool:
 
SPINSTERWUN said:
Yes. It seems as if your tracks were recorded at different sample rates. :cool:
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If that was the case it would sound like chipmunks not a subtle slip in timing over the duration of the song (which is what it sounds like is happening).
 
If CD players will play things recorded at a different sampling rate.....then why do all burners have a converter to change other rates into 44.1? I have a DAT walkman and my Audio burners will not burn things at rates other than 44.1.
Not arguing ya'll......just wanting to understand.
 
Lt. Bob said:
If CD players will play things recorded at a different sampling rate.....then why do all burners have a converter to change other rates into 44.1? I have a DAT walkman and my Audio burners will not burn things at rates other than 44.1.
Not arguing ya'll......just wanting to understand.
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Very few consumer CD players will play anything but 44.1khz. That is the Redbook Standard.

The sampling rate determines the highest frequencies recorded by dividing the sampling rate in half 44.1khz = 22.5 khz max frequency. Some recorders allow a lower rate because it uses up less disc or memory space and is usually labeled as a Speech or Long Play setting. Pro recorders allow a higher rate for better quality (higher frequency response) at the cost of using more disc/memory space.

When you play a recording that was done at a lower rate on a machine that is expecting a faster rate it will drastically speed up the sound. It's not subtle and it sounds like chipmunks on crack.
 
TexRoadkill said:
Once you have both recordings into the computer you might be able to break up the bass track and align the individual parts with the rest of the song.

The only way to reliably sync up recordings done in seperate passes on a single track recorder is to use Time Code or midi sync so the track has an absolute time reference and your walkman probably does not have that.
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I'm with Tex here... it's an old Walkman, and certainly not up to using Midi time codes, etc. Doesn't sound remotely like the chipmunks, though that might help the appeal of our band.

Anyway, I ended up going in and moving the bass part BACK a few ms each verse. Not ideal, but good enough.

Thanks, everyone for your input.
Drew.
 
I thought also that 44.1khz is a loose term, like 48 vdc. When really depending on how much information was transfered it could drift anywhere from 42khz up to 51khz. Just like that 48vdc is affected by ohms law and the resistances and impediances and capicatance changing the way the voltage reacts? I dunno?
 
Jblount said:
I thought also that 44.1khz is a loose term, like 48 vdc.
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No.

If 44.1khz was a "loose term", your music would sound interesting to say the least. It takes a sample every 1/44100th of a second, regardless of what's there.
 
trogdor said:
No.

If 44.1khz was a "loose term", your music would sound interesting to say the least. It takes a sample every 1/44100th of a second, regardless of what's there.
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Which is why recording silence uses up disc space.
 
trogdor said:
No.

If 44.1khz was a "loose term", your music would sound interesting to say the least. It takes a sample every 1/44100th of a second, regardless of what's there.
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Correct but how steady it records and plays back those samples is dependent on the quality of the clock. The most common effect of poor clocking is known as 'jitter' and it can be hard to notice unless you have something to compare too. At the most subtle levels it can create a reduced high end and blur the stereo image.

In the same way a cheap watch might give you +/- seconds every hour a cheap word clock can give you +/- samples every minute.
 
No recording medium has ever used less space to record silence than it has to record music.
 
Derek Verner said:
No recording medium has ever used less space to record silence than it has to record music.
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Are you talking about physical space?

Hard disk space?

What about compressed file formats such as MP3?

Maybe you mean time.
 
Well I think his point is that even on analog tape you're using however many inches per second of tape to record silence........good point actually. hadn't thought of that.
 
I guess that is what I was getting at, it is the quality of the internal clock as to what rate it was actually sampling at and weither or not it stayed at that rate consistently. That answered my question on the subject.
 
Jblount said:
I guess that is what I was getting at, it is the quality of the internal clock as to what rate it was actually sampling at and weither or not it stayed at that rate consistently. That answered my question on the subject.
Click to expand...

Sorta. The rate technically never changes but it's time reference does. It's a bit of a relativity issue.
 
TexRoadkill said:
If that was the case it would sound like chipmunks not a subtle slip in timing over the duration of the song (which is what it sounds like is happening).
Click to expand...

TexRoadkill, you are correct.
 
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