Akai Force Forum: Everything relating to the Akai Force, the new 64 pad, clip-based standalone sampler/groovebox from Akai. While not an MPC, it shares many similar software features to the MPC X/MPC Live including the same underlying code-base.
By HouseWithoutMouse Tue Jun 21, 2022 9:19 pm
I played around with the Force's MIDI connections and noticed some delay I wanted to find out about more. Here's what I found out. If you don't find this interesting, there are other topics. If you don't understand what this means, don't worry, there is no scandal, no disaster, no show-stopper. But for more technically oriented users, this might be interesting.

Live MIDI via Force to outboard MIDI devices

Since the Force's MIDI connectors are of the 3.5 mm variety, it's easy to test how much latency the internal processing adds, compared to direct MIDI THRU. I connected an external MIDI keyboard (Roland JD-Xi) to the Force's MIDI input, and I recorded the THRU signal (which should mirror any signal coming to MIDI IN without any logical data processing or buffering) and the OUT signal from a monitoring MIDI track, onto the left and right side of a stereo track in Ableton Live, as audio. Yes, I recorded electrical MIDI signals directly as audio. Inside Force there was a MIDI track set to monitor and output directly to Force's output. It looks like the internal processing takes a little over 10 milliseconds, so when playing MIDI live through Force, it adds this much extra delay to your note-ons and offs.

One MIDI track, three cables, external MIDI keyboard, computer + audio interface:

- External MIDI keyboard --> cable --> Force MIDI In
- Force Track 1: MIDI, set to monitor input and output to Force MIDI Out
- Force MIDI Thru --> cable --> computer audio input 1 --> Ableton audio track Left side
- Force MIDI Out --> cable --> computer audio input 2 --> Ableton audio track Right side

Image

I wonder if there's a way to reduce this and get more direct MIDI output, for playing "outboard" MIDI devices live. The extra delay in itself isn't that big, but latency adds up, so why not reduce this part of it, if it's possible.

As to why that delay is - I suppose it's there in order to align MIDI and audio output. When the Force decides to output audio "now", it still takes a bit of time for the audio to actually arrive at the physical output, so maybe MIDI events are delayed as well in a "latency compensation" sort of way, so MIDI and audio are output in sync. This would of course be the right thing to do for sequences the Force is playing, but for realtime MIDI I/O, there might be different opinions. I didn't actually compare audio output vs MIDI output of things placed at the same time position in a sequence, but I assume they should line up.

Recording MIDI input to MIDI tracks

One thing that feels odd is, there's a delay of similar length, about 10 ms when recording MIDI - compared to audio input happening at the same time. To me it seems that recorded MIDI events are placed slightly behind on Force's timeline. If you connect Force's MIDI OUT directly to Force's MIDI IN and record MIDI notes through this loopback, the recorded notes are placed on the timeline 10+ ms later than the actual instant when the MIDI I/O happened. For this time offset I can't imagine any useful purpose to be there, because _audio_ that comes in at the same time is placed in seemingly the right place.

How do I know MIDI is placed on a track later than audio? Since it's so easy to record MIDI as audio with the 3.5 mm connections, I recorded a MIDI event coming from the Force, back to its own MIDI track, _and_ the same signal as audio, split out from the THRU connector, onto an audio track, simultaneously.

Three tracks, two cables:

- Force Track 1: MIDI, clip contains a single note, output to Force MIDI Out
- Force Track 2: MIDI, set to record from Force MIDI In
- Force Track 3: Audio, set to record from Force audio input
- Force MIDI Out --> cable --> Force MIDI In
- Force MIDI Thru --> cable --> Force Audio In

Time Correction was OFF, of course, otherwise the timing info of the recorded MIDI would be lost.

To inspect the results closer, I converted the project to Ableton Live and copied the clips from Ableton's session to Ableton's arrangement, where it's easier to zoom in on all the different tracks at the same time. It looks like this:
Image

The recorded MIDI note is placed about 10 ms later than the corresponding audio of the same recorded MIDI signal.

There are a few more things to try about audio vs. MIDI timing. I'll post more pictures if I do more tests.

Maybe this is of interest to someone. I hope this post doesn't offend anyone.