Originally Posted by Simon
EDIT: Lined up Skeeter and yeah, not the same. My copy had to be speeded up again but by more this time, 1.8%, and conversely your copy needed slowing down less, only 2.25%. So, do Skeeter and Marigold on the official releases run at the same speed? I've no idea if you can work that out, but I'd guess not.
Still, that doesn't help us much. My copy runs slow by 0.7-1.8% compared to official sources, yours runs fast by 2.25-2.75%.
I suppose I can compare all of your tracks to mine and see how they compare, if there is much fluctuation.
So wait on any more compares until I have a new version - I'm also going to try and do it as one straight flac file not two.
Meanwhile I've done some note reading and comparing.
Do we have any absolute guarantee Marigold was not tempo adjusted for 2013? I'm guessing not but I just wondered whether there had been any actual comment on what was done to it?
This is a composite of the (applicable) general notes on cassette speed that I have:
"As a cautionary note here, you can never adjust the speed correctly for the entire cassette - the tape will always run a little faster at the beginning and a little slower at the end on account of the changing tape take-up force (back tension is significantly higher at the end than at the beginning,) Also the largest variance is at the extremes of the tape ends, where supply back tension is at its extremes, typically about the first 3 minutes and last 5 minutes on a 90 min tape."
So based on the above it can be expected that when making absolute speed comparisons of even a perfectly correctly recorded and played back transfer that there could (actually should be) speed differences when compared to a confirmed third party source. Recordings get slower over the course of a cassette, with that change being more or less linear over the cassette length EXCEPT for the first and last few minutes where change is somewhat more rapid.
So what's very important with what data we do now have is where the songs are positioned on the tape. Marigold is B1, Skeeter is A5.
Simon 0.7 Slow
Mike 2.75 Fast
Simon 1.8 Slow
Mike 2.25 Fast
It's a shame they aren't on the same side, but nevertheless it should be pretty safe to assume the same playback machine was used for both sides in each case. So this shows that while on different sides, in both cases you have exactly what you would expect to see - a COMPARATIVE speed decrease from the first to the fifth track. In your case it slows by 1.1 percent over five tracks, and in mine 0.5 percent.
Based on the above what can actually reasonable safely be assumed is that your source recording is slow throughout, and mine is fast throughout. And in fact quite usefully because of where the two songs lie in their respective sides the speed difference we have should actually be close to boundary differences for each recording because they are first and last tracks.
Yours 0.7 to 1.8 percent slow
Mine 2.25 to 2.75 percent fast
Mathematically each track of each recording would get slower. So actually after looking at my notes I'm starting to think we have quite a lot there to work with at least from a let's try and see perspective. But again I want to see how another pass of my tape goes on that other deck.
As an aside I have this other note in my stuff too:
"Considering tape duplication machines run at 15-20 times the normal speed, even a slight mis-adjustment on a duplicator can result in a large difference."