MIDI and VU Level Meters

Hello

I’m trying to find out how best to get high resolution, fast updates for VU level meters over MIDI.

I’m building a DIY control surface to interface with Apple logic pro x, and currently using the Mackie Control plugin. The updates over MIDI seem slow and low resolution compared to what is displayed on the laptop.

Can anyone give advice please?

Thanks.

I'm trying to find out how best to get high resolution, fast updates for VU level meters over MIDI.

Can you do that? I didn't think you could unless it is implemented as a sysEx message.

How many MIDI messages can you send in one second?

If you can update the VU meter 10 times per second, that should be fast-enough visually. You can sample the volume a lot faster than that if you want to "capture" the peaks.

.. In other words, you can have high resolution without high display-speed.

I've made a "VU meter" lighting effect and if I recall correctly, I update the display 10 times per second. I'm using a peak detector, so I'm getting the peaks and there's a decay delay ihn software. So it can jump from all LEDs off to all LEDs on in 1/10th of a second, but it decays more slowly.

If you are only sending/receiving control information (no MIDI notes), then the timing shouldn't be too critical and you should be able to dedicate a lot of time to the meter.

The point is where is the information going to come from to send to the meter? It is not available within the MIDI digital domain, it is a function of the analogue circuits in the tone generator.

How many MIDI messages can you send in one second?

MIDI runs at 31250 Baud, so that's 3125 bytes per second and with three bytes to a message that gives 1041 messages per second.

I'm hoping I can get the information from Logic. Or some workaround somehow.

Currently, I update my meters from the MIDI Channel Aftertouch "0xD0" message out from Logic.

Am I missing any other MIDI messaging?
Is there anything via SysEx?

I want to improve on what I have, it is pretty dismal tbh, but I'm not sure how.

I'm hoping I can get the information from Logic. Or some workaround somehow.

I would do that before you go any further with the project.

urrently, I update my meters from the MIDI Channel Aftertouch "0xD0" message out from Logic. ...... it is pretty dismal

I would expect it is. As I said this is a function of the tone generator so you need to hack into that.

Thanks Mike

So you don't think I've missed a MIDI message or something in SysEx?

If I set logic up to use a different control surface, are there any out there that offer better level meter displays?

Its been suggested to use a plugin called Reaktor. I didn't want to have to do this unless absolutely necessary.

Really appreciate your time and help.

Sorry I know little about control surfaces for Logic, it was in the late 90s when I used Logic and then it was mainly got for my son. Same with Reaktor, but as that is a sound module it is feasible that this could send back volume data.

A bit late to answer to this topic... but I hope my information will be interesting.

If you use RPN or NRPN Control Change, you can get 16384 levels (coded on 7+7 bits), which seems more than sufficient even for a ultra very high resolution VU-meter °-)

For a VU meter, a classical Control Change on 7 bits seems however more than sufficient for me (127 levels = not sure than an eye would be able to see a difference on a LED ladder with 128 LEDs).

And since these messages are just Control Change, you can send 1000 (for RPN/NRPN) to 2000 (for single CC) before you reach MIDI 1.0 bandwidth. You would not need SYSEX to do that.

Now, if you are really afraid of reaching the MIDI bandwidth, you can take a look to RTP-MIDI, which is transporting MIDI over Ethernet (RTP-MIDI - Wikipedia)

Howdy folks, I'm trying to do something similar....would like to mimic LEDs from AU plugins on a DIY controller, through logic. Anyone willing to offer up some advice where to get started on this? Maybe together we can figure this out.

No you will not get help resurrecting a four year old thread.

Read the rules, that how to use this forum sticky post.

Then start your own thread, we will be happy to help then.