Sliding down onto a note

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gonzoB
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Sliding down onto a note

Post by gonzoB »

Not sure if this is a bug, or an incorrect setting.

When I slide down onto a note by partially covering a hole, the note bends down, then when I cover the hole completely I get a note about a semitone below where it should be. If I simply stop blowing, not move my fingers, and start blowing again I get the right note.

Is this a function of the synth's pitchbend range? Or a bug?

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Re: Sliding down onto a note

Post by admin »

It sounds like something with the synth's pitchbend range-- with firmware 1.8 (the current release) the pitchbend range in your synth should be set to two semitones. Then the maximum pitchbend when you are slightly down (or up) should be the same pitch as the destination note (when you put your finger down all the way after sliding down or lift it up all the way when sliding up). In the next firmware, you'll be able to select the pitchbend range in the WARBL configuration to match it to your synth in case you can't set it in you synth. There will also be a "legto" slide where the slide is continuous and won't trigger a new note when you put your finger all the way down.

If your synth is already set to two semitones, let me know and we can pursue this further.

Thanks!
Andrew Mowry
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gonzoB
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Re: Sliding down onto a note

Post by gonzoB »

I got that funny result on my XpressO synth. I just tested my RPi Fluidsynth, and my Roland JV1010 and they perform correctly. I checked the noteons and they were correct, so I think it's a bug with my XO.

Thanks for the explanation. I'll do some more investigation.

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Re: Sliding down onto a note

Post by admin »

What fingering chart are you using? This also sounds like it could be related to the way vibrato works, i.e. it looks at the fingering pattern when the note is triggered (e.g. when you start blowing). Using vibrato to bend a note all the way down by covering a new hole completely, then stopping blowing and starting again will retrigger the note without any vibrato, so the pitch will be higher again though your fingering hasn't changed. That may seem a bit odd at first, but it seemed like the most logical way to do it, i.e. it's assuming that with vibrato you won't leave the finger down all the way and then trigger a new note. Or, it assumes that if you trigger a new note you won't intend to lift a finger to cause vibrato, instead you'll lower another one. It ensures that wen you begin playing a note, it always plays in tune. The "custom" vibrato for some bagpipes is an exception to this, because it lets you lift a finger to play vibrato (because the GHB and Northumbrian charts use closed fingering patterns).

The difference between slide and vibrato when you have both turned on is that only the highest uncovered hole is used for slide, and the rest are used for vibrato (or whichever ones you have turned on). I'm guessing it may be vibrato, not slide that is causing this, as described above.

Edit-- I just saw your reply while typing this. If other synths are behaving as you would expect it may indeed be a synth-specific thing, maybe with the pitchbend range, in which case you can ignore all of the above :)
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Re: Sliding down onto a note

Post by gonzoB »

OK, fixed.

It's an issue with the XpressO. Ingo (the developer) has a setting for this. You need to set Pitchbend Mode to "String Pitchbend" It automatically sets the pitchbend to the midpoint on note change. It's actually quite useful for my EWI as well. The only drawback is that you need to set it for each preset. works beautifully now!

Andrew, while investigating this I discovered that the WARBL resets the pitchbend to one below the midpoint, and it does it approx 16msec after the noteon/noteoff command comes through for the note you are sliding to. Is that what you intended to happen?

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Re: Sliding down onto a note

Post by admin »

Great, I'm glad you got the pitchbend issue sorted out.

Yes, currently pitchbend messages are sent every 20mS, regardless of whether a note has been sent recently. You may have seen the comment in the code about that, but it's a bit of a workaround because some synths like the Aria engine and Celtic Sounds (until it was changed recently) make a pronounced "pop" sound if you send pitchbend messages immediately before or after a new note is triggered, so WARBL purposely doesn't send it then. In the next firmware, you'll have the option of sending a new pitchbend message immediately before a new note is triggered, which is apparently a requirement for MPE. Jesse Chappell of Thumbjam and Sonobus has been helping me with the firmware and setting me straight on a lot of these details for MIDI protocol.
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