I tried a similar test with the Flute, Soloist Bossa Ev 140. I created four .WAV files at different BPM: 140, 120, 100 and 80.

I'm rather shocked by what I found.

PG Music advertises:
Quote:

the superior stretching features in Band-in-a-Box...


But based on my informal testing, I'd be hard pressed to call BiaB's algorithm "superior" to anything else I'd tried. Rather, it seems that it's comparable to the low-end algorithms, and rather inferior to other algorithms.

At 120 BPM, I didn't hear any artifacts from BiaB. At 100 BPM, there was objectionable warbling. 80 BPM was considerably worse.

I performed the time stretching in Audacity. BiaB seems to perform slightly better than Audacity, but not much.

Similarly, the SoundTouch algorithm in Reaper was perhaps a bit worse than BiaB, but neither Dirac LE nor elastique 2.1 Pro exhibited these artifacts.

Don't get me wrong: I love RealTracks, and PG Music offers an excellent product.

I'm just disappointed to find that "superior stretching features" don't appear to appear to be superior to anything other than the low end algorithms out there.

Still, it's very heartening to think that the lower tempo limit for many RealTracks could be be brought even lower, giving even more flexibility to users.

And if I've made a mistake in my methodology, I apologize!