I create loops for myself, so I figure I might as well share them with the world, for free. All loops are free to use for whatever you want, no attribution needed. However, I would appreciate hearing any music that uses any of my loops :)
I create loops using extremely specific BPMs (see list below) because 1) they divide evenly by all note subdivisions down to a 256th note in Audacity (which uses three places after the decimal point) so I can be ultra precise and 2) I often batch convert files to different BPMs and the converted file length comes out exactly precise.
So, if you want these to loop exactly as they are without time stretching them, use the original BPM in your DAW. However, they will stretch to any BPM very well because they are all cut to exact durations of a whole note, two whole notes, four, eight etc.
All that being said, not all loops are mathematically quantized in feel. I sometimes intentionally line up transients to be either before or after the quantized beat. This is especially true for things like shakers, maracas, eggs etc. Things with sharp transients are usually much more quantized, because that's the sound I prefer for that type of instrument.
Some loops may APPEAR to be out of time, because the first sound occurs after some silence. In some cases some loops may have more silence than sound. Or the main "action" may occur around the middle, with either silence or some kind of buildup leading up to the main sound. But I assure you that all of them match up to the BPM stated in the upload, so if you place them in a song at the beginning of a bar, it will be in time.
I typically normalize all files to -3 dB and most have a fairly narrow dynamic range. -15 to -3 is pretty typical, but sometimes it could be more like -24 to -3 or even -36 to -3.
Experiment and have fun with these! Files that I upload as packs are meant to be used in combination with each other, and most will sound good placed in any order you combine them. Try cutting them to .5 times the length, or .75, or 1.5 or 2.25 etc (I always indicate the length of a quarter note in the upload, so figuring out where to cut it should be easy using some simple math - Excel is your friend!). Get creative with them!
BPMs I have used / plan to use for ulpoads
78.125 (quarter note = .768)
85.22727273 (quarter note = .704)
93.75 (quarter note = .640)
104.1666667 (quarter note = .576)
117.1875 (quarter note = .512)
120 (older uploads - will not be used going forward) (quarter note = .5)
133.9285714 (quarter note = .448)