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Problem with Midi quality data

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hicham
Posts: 4
Active Member
Topic starter
 

Hello everyone, I'm writing from Belgium about a problem I have connecting two hardware instruments. I'm connecting an Alesis Percussion pad to an Arturia Keystep pro (midi controller) which is itself controlling a synth.

The problem is between the Percpad and the Keystep. When I'm recording notes sent from the Percpad, I have a loss of notes that happens randomly.

I tried with a Roland SPD instead of Alesis percussion pad and it works just fine. I tried several midi cables and apparently with the Roland midi cable, I'm getting better results but still not perfect. That's why I think it's a signal quality issue.

My opinion is that the Alesis Percpad has a poor compatibility with the Keystep pro even if I don't get why..(The Alesis Percpad works well with other gear sending midi signal with any cable)

My question is:

How could I improve the quality of the signal? In your opinion, if I change the amperage of the DC Adapter of the Percpad, will I get a stronger signal? (please don't make fun of me if it's a lousy idea). Any other suggestion except changing the cable? I tried with Midi Solution Thru and it doesn't change anything..(Maybe the Thru box needs to be DC powered?)

Thanks for your answers.

Ps: Sensitivity is set at Max level and it doesn't change if I hit hard the pad or not.

Temporary video in the link

 
Posted : 13/12/2022 3:28 pm
Geoff
Posts: 1043
Noble Member
 

Some of what you're saying here seems to refer to sound quality, which is nothing to do with MIDI, which is just numeric codes for commands. Again, nothing to do with 'sensitivity.

Certain cheap MIDI USB cables are known to drop midi data, stay away from them, although they CAN work in SOME situations. The Roland connector is known to usually work well, if you have problems here then the problem is coming from somewhere else.

Please be clearer as to what the problem is, and where the sound is being generated.

Geoff

 
Posted : 13/12/2022 5:14 pm
hicham
Posts: 4
Active Member
Topic starter
 

Thanks Geoff for your answer.

There is no audio involved here. It's not even connected. Only two machines communicating through a Midi 5 Din cable. No USB either.

The sensitivity of the pad affects the output midi note's velocity.

Today I tried to increase the DC power amperage of the Percpad and it didn't change anything. (Even tried 10 volts instead of 9 volts)

I'm gonna try with Monoprice cables and see if there's a difference.

 
Posted : 14/12/2022 8:48 am
Geoff
Posts: 1043
Noble Member
 

What you describe here has nothing to do with cables or DC power.

You hit a pad, and a sensor in the PercPad generates a velocity value and sets this to a numeric value (between 1 and 127 I assume). This value is now fixed as MIDI data. It could be that there is a setting within the PercPad that can adjust this, but changing the cables, or DC power, will NOT change anything.

If you are sending the MIDI data to a DAW or some other computer device that allows you to store (as a MIDI file) or just as data, then there might be some facility to manipulate the MIDI data, which might well include the ability to change all/some volume levels.

I don't know why the present sensitivity of the PercPad is not enough for you. Can you see the values created now? If you make the quietest note you might normally make, what Velocity does that show? If you make the loudest note you might ever make, what velocity is that? The first cannot be less than 1, The second cannot be more than 127. A sensitivity control cannot change that. If you change the data afterwards on the computer, you're still constrained by the 1 to 127 range.

Geoff

 
Posted : 14/12/2022 9:26 am
hicham
Posts: 4
Active Member
Topic starter
 

Thanks again Geoff for taking time to help me out.

You're right, the sensitivity has nothing to do with my problem. Sometimes the midi note is recorded, sometimes it is not, whatever its velocity is..

My first clue was the difference in results between different cables. That's why I thought about the quality of the signal. Then, because when I sent the same signal with another device (Roland spd), I got all the notes recorded, I thought that somehow, the cc note was correct, the velocity as well, but something in the signal wasn't "enough".

Here is a question that will help me to understand where my problem is:

How the difference of quality between two cables carrying an identical signal can affect the data?

 
Posted : 15/12/2022 12:55 am
Geoff
Posts: 1043
Noble Member
 

Hmm?

As I've said, the MIDI data is just numbers. Once it's created (by the PercPad) then it is fixed.

If it is actually changing, then something is changing it, and this is not the cable. Unless your cable is willfully malicious?

Either the Keystep ? or the keyboard must have something set that is changing the velocity numbers. Why I don't know. I don't know anything about the devices you're using but there might be some control re Master Volume (which would change everything by a certain amount) or something like compression/expansion which might change some levels more than others.

Another way of saying - the MIDI signal contains data, and regardless of the 'volume' of the signal it still contains the same zeros and ones that make up the binary data. If the signal gets to be too weak or too loud then it may not be received properly and this may scramble the data totally,which would totally mess it up, but it would not affect just the velocity of the resulting midi sounds.

Geoff

 
Posted : 15/12/2022 5:21 am
hicham
Posts: 4
Active Member
Topic starter
 

I think I have found what the problem is..

It's about note lenght. I tested both machines in LogicProX and saw huge difference between Roland SPD's and Alesis PercPad's midi notes durations.

I found this forum where the guy is having a similar issue with another gear..
https://forum.cockos.com/showthread.php?t=182328

Conclusion: Nothing I can change..I wrote to Arturia asking for help but I'm not expecting too much from them.

 
Posted : 19/12/2022 1:15 pm
Geoff
Posts: 1043
Noble Member
 

I would suspect that it is the PercPad that is causing the problem, but if so, why are you writing to Arturia? You should be writing to Alesis to ask if there's any way their device can help.

But, it COULD be the Arturia device that is causing the problem, if it sees a Note On with no Note Off and then adds a Note Off immed after the Note On to keep things tidy (it thinks).

Percussion sounds usually do not NEED an explicit Note Off as the envelope provides - in effect - a note off anyway.

You cannot really use a default Note Off as different percussion instruments would have a different length caused by their different envelopes.

Geoff

 
Posted : 19/12/2022 2:58 pm
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