Is this tape a drag or what?

[eieio]

Hi,
Has anybody ever had this happen:
I'm "unmixing" my old 1/4 inch 4 track analog recordings of originals to an MX-2424. I began with a tape of 4 full tracks recorded on a Teac A3340S. I dumped those tracks to the MX. I then did the same with the next tape of 4 tracks (containing the mixed down version of those first four tracks plus three overdub tracks)and laid those alongside the first 4 tracks in the MX. - NOTE- (There were two different Teac decks used originally, both A3340S models, fairly new). Then I nudged the two groups of 4 tracks into sync on the MX. Upon playback I expected to hear all of the eight tracks in sync but that didn't happen. They started out fine, but after about one minute the second group of 4 tracks seemed to slip ahead in speed slightly until finally finishing about 5ms sooner than the remaining 4 tracks,even though they began EXACTLY in sync! Any ideas of what is going on here? Could it be because they were originally recorded on two different reels of tape or machines? Any thoughts on how to correct the problem?
Thanks.

 

[A Reel Person]

I dunno if tape's a drag,...

I guess it's a matter of who you ask. I'd never say that.

Unfortunately, the technical part of your question shows some of the inherent limitations of analog. I don't know of any really good fix for this issue. Sorry! Time compression algorithms on the DAW is about the only thing I'd recommend trying, although I don't think you'll get a perfect match, & I don't know anything more about it. Maybe try the computer recording forum.

Analog still rules, anyway!!!

 

[cjacek]

Hi,
Has anybody ever had this happen:
I'm "unmixing" my old 1/4 inch 4 track analog recordings of originals to an MX-2424. I began with a tape of 4 full tracks recorded on a Teac A3340S. I dumped those tracks to the MX. I then did the same with the next tape of 4 tracks (containing the mixed down version of those first four tracks plus three overdub tracks)and laid those alongside the first 4 tracks in the MX. - NOTE- (There were two different Teac decks used originally, both A3340S models, fairly new). Then I nudged the two groups of 4 tracks into sync on the MX. Upon playback I expected to hear all of the eight tracks in sync but that didn't happen. They started out fine, but after about one minute the second group of 4 tracks seemed to slip ahead in speed slightly until finally finishing about 5ms sooner than the remaining 4 tracks,even though they began EXACTLY in sync! Any ideas of what is going on here? Could it be because they were originally recorded on two different reels of tape or machines? Any thoughts on how to correct the problem?
Thanks.

On any one Analog tape machine you'll get slight speed variations which become apparent later on in experiments such as the one you outline. Unless you record "in sync" from the get-go, you'll always have this type of problem. It's not unusual.

~Daniel

 

[FALKEN]

there may be a way to approximate what you are doing. if there are silent spots in either sets of tracks, you could split them there, and drag them a few ms over, and compensate. this might help. if there are no silent spots, you could try tapping the tempo, and drop a marker on a downbeat and splice there. by doing this a few times, you might be able to make the difference less noticeable. I haven't tried this, just a thought that comes to mind.

 

[The Ghost of FM]

Offset the slower track to start 2.5 ms before the speedier one and then you will achieve an overall 2,5 ms differential between the two generations of tape which should not be noticeable to the average listener.

Otherwise, take the offending track into a DAW with a time stretching/compressing utility, make the necessary adjustment in length and fly it back into the MX2424 to do what ever it is you were intending to do...remix, I assume?

Cheers!

 

[Farview]

You also realize that with speed variations comes pitch variations. The further off the speed is, the more out of tune these tracks will be with each other.