relationship between user/computed BPM for samples and patterns

[rvosa]

Hi Matthew,

first of all: bless you for making this app! I think this is going to be very helpful so I salute you for putting your spare time into this. I don't strictly speaking have an issue, but just a confusion.

I simply do not understand how the SP deals with the BPM of samples, how I can affect that in your app, and how this interacts with the BPM of my sequencer patterns. My workflow is as follows:

• I compose patterns in Ableton live and export every instrument/loop warped to the same BPM (130)
• I assign these loops to different pads, and the SP seems to recognize they're 130BPM in the display
• I then sequence the loops in quantized patterns

(Unfortunately, I've been bugged a little bit by how the timing when triggering these loops in a quantized pattern seemed sloppy.)

Being new to your app I was surprised by a couple of behaviors of the SP. Apparently, the machine doesn't precisely compute the tempo: when I read the SD card after it's passed through the machine, I noticed that your app shows the computed BPMs are 129.9 according to the SP. The machine is wrong because the loop lengths are surgically precise to the same length as warped by Ableton.

So what is going on here and what should I be doing? What happens under the hood when I set it to 130 in the BPM fields? What do I do for tempo mode?

Thank you very much for any explanation you might be able to provide.

Cheers,

Rutger

[MatthewCallis]

How long are your loops? I can try recreating this this weekend to help better explain it.

[rvosa]

8 bars @ 130 bpm. Thanks!

[MatthewCallis]

I'm noticing the same issues, I believe it has to do with the internals of the machine and I don't see this documented in the manuals (only the mention of even and increments by 3 at higher BPMs which doesn't seem to be the case)- the values are written and read exactly as shown.

I will need to run some tests to figure out exactly what it happening. Thanks for bringing this to my attention, this is actually really interesting. 🧐

[rvosa]

My pleasure 🙂 I wonder if this is simply a type of rounding error?