AU polyphony settings?

Does anybody know of a way to set the polyphony of individual AUs (tracks), as opposed to the polyphony of a sampled (internal) pad (pad in the BM3 on-screen button sense)?

I have 2 tracks with AUs to act as layering on input MIDI channel 1, and 1 track with an AU on input MIDI channel 10. The input is from external USB MIDI for all of these tracks.

I can play on channel 1 just fine (one layer is KQ Dixie with a transient patch, the other is Lorentz, which has a pad/drone type of patch). However, when I start playing the drums into channel 10 (a drum kit on bs-16i), the drum track very quickly steals notes away from my "drone" and cause it to drop out.

I would like to limit polyphony on the drums to perhaps 2 or 3 notes, so priority goes to my drone/pad track. Any ideas? Or is total vs per-track polyphony not even the issue???

Footnote: it's unfortunate that the word "pad" in this discussion can mean either of two things: a slow/sustained patch vs a button on the screen :-(

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  • AU Polyphony us handled by the plug-in.
    If I don't recall wrong it's possible to set a KQ Dixie patch into mono-mode.

  • Hi,

    I've never personally encountered a per-track 'polyphony' issue like you describe, but in theory there must be a maximum number of midi notes that can be received simultaneously, either per midi channel, or the maximum the app can handle at once. I expect whatever this maximum is, it's probably much higher than you are able to achieve with 2 hands and 2 feet all playing something at the same time ;)

    In theory, if you caused Beatmaker to receive more notes on a channel that it could handle, I suppose it might switch off notes on your synth-pad to make room for the incoming drum notes ('stolen' notes, as you put it). But this still seems unlikely.

    Is there a reason they all need to use midi channel 1? Are you playing all 3 instruments live from the same controller? (and you do only have 2 hands, right? ;))

    ps. I suggest the words synth-pad and trigger-pad to help avoid confusion with these 2 homonyms

  • @samu said:
    AU Polyphony us handled by the plug-in.
    If I don't recall wrong it's possible to set a KQ Dixie patch into mono-mode.

    Thanks for the tip. I just checked all 3 AUs in use. The synth suffering the drop outs is only set to polyphony of 8 in its settings. The others either can't be changed, or are already at the lowest setting.

    I don't understand the relationship, if any, between how notes/"voices" are allocated between the AUs, but the soft-synth dropping out has the lowest polyphony, so I should try to bump that up the next time I have everything all wired together again. It's weird that Lorentz works just fine when channel 10 isn't pumping out drums, but maybe if I give it a higher polyphony number more resources at some level or other in the software stack will be given to it.

    Experimentation is called for!

  • @tk32 said:
    Hi,

    I've never personally encountered a per-track 'polyphony' issue like you describe, but in theory there must be a maximum number of midi notes that can be received simultaneously, either per midi channel, or the maximum the app can handle at once. I expect whatever this maximum is, it's probably much higher than you are able to achieve with 2 hands and 2 feet all playing something at the same time ;)

    In theory, if you caused Beatmaker to receive more notes on a channel that it could handle, I suppose it might switch off notes on your synth-pad to make room for the incoming drum notes ('stolen' notes, as you put it). But this still seems unlikely.

    Is there a reason they all need to use midi channel 1? Are you playing all 3 instruments live from the same controller? (and you do only have 2 hands, right? ;))

    ps. I suggest the words synth-pad and trigger-pad to help avoid confusion with these 2 homonyms

    I've got a basic Casio "arranger" type keyboard connected via USB MIDI. The drum track is sent on channel 10, per general MIDI convention. Channel 1 is just me noodling, but I have a layer receiving it. One synth is providing a "transient" part of the layer, the other synth is providing the "sustain" part of the layer, but the would-be sustain part keeps dropping out once I start the drums playing.

    As samu mentioned, I can adjust polyphony in the individual soft synths. In this case, the synth that is dropping out has the lowest configured polyphony. I need to check the CPU meter, but my wild guess would be that BeatMaker (or iOS???) is trying to ration out resources (of an iPad Mini 2) by taking from the synth with the lowest indicated polyphony to "donate" available notes to one with a higher (but wasted, really) polyphony setting.

  • edited September 23

    One tip is that Synth-pads which have long release tails still count towards your polyphony even once you take you hands off the keyboard (if they are in the process of releasing/fading out).

    You probably know this already, but for example, lets say I have 8-note polyphony on a synth. I play a 5-note chord on on a synth with long release, then take my hands off the keyboard and play another 5-note chord before the first chord had completely ended (it's probably still fading out). In this situation, the synth will cut off 2 notes from the original chord to make room for the new 5-note chord.

  • Why am i completely lost here ?
    If synths are recieving channel 1 and drums are recieving channel 10, which channel are you playing on the keyboard, because channel 1 will only play the synths, channel 10 will only play the synths.

    If something else is happening, it is either wired up wrong, MIDI settings wrong, or explained wrong.

    If you pop in to the realtime chat (discord linked top of forum) myself and others will gladly help you in realtime (think family guy a team episode) to achieve what you want to achieve ;)

  • @tk32 said:
    One tip is that Synth-pads which have long release tails still count towards your polyphony even once you take you hands off the keyboard (if they are in the process of releasing/fading out).

    You probably know this already, but for example, lets say I have 8-note polyphony on a synth. I play a 5-note chord on on a synth with long release, then take my hands off the keyboard and play another 5-note chord before the first chord had completely ended (it's probably still fading out). In this situation, the synth will cut off 2 notes from the original chord to make room for the new 5-note chord.

    Yep. Which is why I was trying this with and without the drum track coming in. When the drums (channel 10 in) were not running, I could sustain a note with my left hand just fine, no drop outs, while plinking around with my right hand (all coming in on channel 1, but mapped to 2 synth tracks to create a layer effect).

    That said, I got a chance to try this again this morning. Bumping the polyphony of Lorentz up to 16 to match KQ Dixie fixed the problem. I can't change polyphony on bs-16i, which is "locked" at 64 to play back GM files I guess, even though I am only using it for a drum track (I can buy an upgrade to get 128, but that's neither needed nor wanted in this case).

    As far as I can tell, either BM3, or something in iOS, is trying to "weight" allocation of polyphony by looking at the requested polyphony for each instrument / soft-synth AU, even though they are on different channels, and arrive at some sort of pro-rated reduction in polyphony. Bumping Lorentz up seems to give it a big enough slice of the total pie (across all channels / AUs).

  • Nothing controls polyphony other than the synths own settings.
    You have it set up wrong, sounds to me like you have a keyboard set up that is either sending all channels or you have the MIDI set up wrong in B3.

    You havent really been clear so far.
    Are you trying to play the synths with one hand on the keyboard, and the drums with the other hand on the keyboard, if so your keyboard needs to have a split feature.

  • @5pinlink said:
    Why am i completely lost here ?
    If synths are recieving channel 1 and drums are recieving channel 10, which channel are you playing on the keyboard, because channel 1 will only play the synths, channel 10 will only play the synths.

    If something else is happening, it is either wired up wrong, MIDI settings wrong, or explained wrong.

    If you pop in to the realtime chat (discord linked top of forum) myself and others will gladly help you in realtime (think family guy a team episode) to achieve what you want to achieve ;)

    Problem solved: increase polyphony setting of the AU which had the lowest polyphony count.

    FWIW, the keyboard keys are sending out on channel 1. The arranger-type keyboard also has a pre-programmed drum part which is acting like an external sequencer sending (drum) notes out on channel 10.

    It doesn't make too much sense, but somehow sending notes into channel 10 ate into the number of sustained notes available to one of the synths on channel 1, until I bumped up the share for the synth AU that was dropping. When channel 10 was inactive, there was no dropping, which is why I suspected there was some interplay between requested polyphony of each AU, and the resulting polyphony when they all started taking resources at the same time.

    One AU was asking for 64, one for 16, and another for 8. It's like iOS or BM3 said "You can't have (64 + 16 + 8 =) 88 notes playing at once, how about 44?" (32 + 8 + 4, as in half of what each asked for, or something along that line). Once I changed the settings to 64 + 16 + 16 (reconfigured polyphony for each of the 3 AUs), it behaved as if the resulting polyphony was 32 + 8 + 8, which worked just fine.

    Keep in mind that I am running (iOS 11.4.1) on an iPad Mini 2, not a recent model iPad Pro :-)

    Does that help at all?

  • Doesnt matter, neither IOS or B3 have snything to do with polyphony, your fix may have worked, but it has reset something or pther, one MIDI chanbel cant affect another, more likrly the MIDI oytput from the was weird, or you had Omni on or something.
    Glad its working though.

  • @5pinlink said:
    Doesnt matter, neither IOS or B3 have snything to do with polyphony, your fix may have worked, but it has reset something or pther, one MIDI chanbel cant affect another, more likrly the MIDI oytput from the was weird, or you had Omni on or something.
    Glad its working though.

    Well, there's got to be some kind of limit eventually. My iPad, at least, is not a supercomputer, and if I loaded up 16 AUs, and set the polyphony to 128, then hooked up an external sequencer running a "black MIDI" piece into it, I suspect you would hear some dropouts :-)

    https://en.wikipedia.org/wiki/Black_MIDI

    I guess the question of the day, is for a given piece of hardware, and a given set of soft synths (CPU load varies...), when do you hit the limit, and what happens?

    In my case, I'm certainly not playing many notes on the keys, but there is a sequencer banging off some drum notes independently.

  • You will NEVER get one particular synthesiser dropping notes because of extra MIDI on another channel, it is entirely impossible unless the developers have teamed up and made some shared resource plugins (they havent by the way) you would get audio drop outs and or crackles/popping.

    This has nothing at all to do with CPU and everything to do with MIDI be it not set up right or poor information coming from the keyboard ;)

    If its working, who cares ;)

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