Wav speed correction question

[Bob Romano]

I have an Akai Quad 8 track player. The motor is a bit old obviously so depending on the tape played it can be anywhere from a little slow to a little more slow.

I have some quad 8 tapes that I want to convert and, though they sound decent enough, they run slow.

My question is -

Is there a program or a method I can use to speed correct the files once they are recorded? I have Nuendo, Wavelab, WavePurity and Sound Forge but I am not sure if they can do what I need. I know Wave Purity will correct the files but how do I know when they are "right"?

I need to be able to compare the recorded file to A440hz to make sure they are in tune.

Thanks
Bob

 

[winopener]

What i do in Audition is:
1) record the 4 channel sound
2) get a CD or a file of the same recording in stereo
3) do a very crude downmix to 44.1/16/2ch of the 4 channel sound, same section of the point 2.
4) load em both in the multitrack view and speed up/down as needed the 4ch downmix until it syncs perfectly with the stereo. Then i know how much i need to change it.

 

[ArmyOfQuad]

I usually speed correct with sound forge. I'll load in a cd version or something that I trust to use as a reference, and find 2 points in each file, like a snare hit, that I can easily mark, so I now have a segment that should be the exact same length of time in each file. Double clicking on the segment between the 2 markers will highlight this area, and list the amount of time it is on the screen somewhere in the corner, which on my cd file will give me my target time. On the file I wish to pitch shift, I'll double click on the segment to highlight it, go to the pitch shifter in sound forge, and it will list the final length of the segment after shifting allowing me to adjust the amount of shifting until I get as close to the target time as possible. Once I find the amount of pitch shifting necessary, I cancel out, select the whole file, and pitch shift. If all went as planned, the 2 files should now sound identical, as far as pitch goes.
Or, you could just do it by ear, which I've done at times when it isn't as important to be quite as exact.

 

[winopener]

Side notes:
- of course the real speed variation on the 4ch files is *decisely better* if started and done at 96k sampling rate;
- as a "compare source", even the 1-min. sample that you can find on "listening preview" on amazon, cduniverse etc can be enough; it doesn't matter if quality-wise it sounds like crap, what does really matter here is the speed, and once a sound went from analog to digital the first time there's no way it can speed up or slow down at all by itself: speedly-wise it remains the same even in mono and 64Kbps mp3.

 

[ChristopherLees]

I use a Tascam Da 88 8 track digital tape machine(it uses hi8 tapes).They are getting cheap on ebay now and have built in variable speed control, as well as time/delay adjustments om individual channels.records at 44 or 48k, and you can get them modified to run at 96k(they used 2 96k versions for the yellow submarine movie dvd).

it is very easy to use, just like any tape recorder and you can add your .1 bass channel at the same time....but you still need to compare it against the stereo release ...I just tune it till it's on pitch and in sync with the stereo cd or lp.