Weird pitchbend problem. Need some help…

Can anybody confirm this behaviour in iOS synths:

Pitchbends coming from Hapax results in +/-48 bends, disregarding their pitchbend setting.
I have the problem with Virsyn Tera Pro, Bleass Alpha and Moog Model D.
But many other synths behave normally.
It seems that the “problem-synths” interpret pitchbends that come from Hapax as MPE pitchbends. Although I am not very techy when it comes to knowing the difference between the two, I can see in a midi monitor in AUM, that a normal pitchbend looks different from the ones from Hapax.
If I take Hapax out of the chain, and go directly from my Matriarch keyboard to AUM there is no problem. But when the Matriarch goes into Hapax and then on to AUM, then some synths will go nuts with the +/-48 bend range. The same if I setup an assigned knob to send pitchbend.
And just to be clear: I am not using MPE tracks in Hapax.

So why does Hapax seemingly change a good old fashioned pitchbend from my Matriarch into something that some synths will interpret as MPE +/-48 pitchbend?

I can’t confirm with iOS apps because I don’t have any, but it sounds like a possible midi loop that’s compounding the PB message. Since I don’t know what your routing looks like, it’s difficult to assume a solution, but you just want to make sure that the Matriarch isn’t receiving it’s own PB signal (then resending, and receiving, and so on).

Just a hunch based on similar issues I ran into when figuring out how to get my 3 Elektron boxes to use their midi tracks to send extra LFO’s to each other

Hi LarsDaniel,
I just tested it with Model D in AUM. When I send PB from HAPAX or record in HAPAX and play it back, everything behaves as expected. In any case, the result follows the settings in the Model D.

Greetings, Michael

Thanks for checking!

@braken I took the Matriarch completely out of the equation. But the problem persists just using pitchbend from a Hapax knob. So no midi feedback loop.

But there is a development:
When I turn on Hapax, the pitchbend works as expected in my iOS synths. Then I load my project in Hapax, and still using a PB knob in Hapax, the PB range in the receiving synths suddenly go to +/-48.

Still very mysterious, but at least there is some degree of progress.
Any ideas are welcome.

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Ok, there was a brief moment where pitchbend was working right, but now I can not reproduce it. :exploding_head:

Even if I reboot Hapax and start from clean slate in AUM, pitchbend is that horrible +/-48.

I am losing my mind here.

I dont totally understand what you are saying in your posts…but

if the pb range is changing in AUM (or any synth), it’s from MPE NRPN messages.
(this is the only way for pitch range to change)
connect a midi monitor and check for them… then you can determine source.

MPE synths should only use these NRPNs for pitchbend range IF they are in MPE mode.
but there are some inconsistencies/holes in the MPE specs, which leaves room for interpretation,
which can cause issues.

(Ive discussed some of this with Squarp, and I think it’ll be reviewed when they move onto the full MPE mode … but at the moment the MPE tracks are a little limited)

note +/-48 is the default MPE pitchbend range, and alot of synths/controller etc. that don’t have “full” support will just use 48. in practice this is OK, as everything matches up nicely BUT of course, is dreadful when not using MPE :wink:

Thanks. I have just spent four hours on this and have managed a bit progress. (But basicallly I am ready to kill somebody.:man_shrugging:t3:)
I think you might be right about there being some inconsistencies in MPE.
And there seems to be two types of pitchbend:


But I don´t know the meaning of this.

One thing that was confusing me was, that a synth like Tera Pro and Bleass Alpha work fine if they are on midi channel one, but on any other channel they go +/-48. After realizing this, I was like, oh, so the synth thinks this is MPE. But with Alpha, I can not find any MPE or midi settings (and a manual does not seem to exist), and on Tera Pro, no matter what I do with the midi/MPE settings, nothing changes. The only way Tera works right is on midi channel 1.

I have looked for NRPN messages but none shows up.

Anyway, my brain is fried, and I am never gonna get those hours back. I think I will give up on this one and move on with life.

oops, I meant RPN, not NRPN.

no, there is only one midi pitchbend message, and as I said, its doesn’t contain any information about pitch…
the reason you see 0xE3 and 0xE4 is because these are on different midi channels , the lower nibble is used for midi channel, on all channel based midi messages.

the best way to think about this is…
when midi started out, we just had a pitch wheel… so the pitch bend message is just the position of that wheel… synths were then free to decide how to interpret that wheel position… so different bend values, or even asymmetric bends.

this only had to change with MPE (and microtonal controllers) because we use pitchbend to slide between pitches, and to allow for microtonal pitch or ‘fractional notes’.
at that point, the standard kind of changes… no longer was it just a control function rather the PB message had to some how convey real pitch, but you can only do that if both sides know/agree on the range. hence the RPN messages.
(iirc, this’ll all change again in midi 2.0 … and hopefully MPE will become redundant)

still the question is … whats sending the RPN messages, and why? and can you stop the synth being in MPE mode.

unfortunately, I dont really use iOS for music, so dont have a way of looking into these specific issues.

Long story short: Tera Pro has a problem, but at some point in the investigation, I thought Hapax had a problem. So I am just leaving that synth for now.

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