polyphony limit at 18?

So, an embarrassingly noobish question about polyphony on the mpc.

I'm running 2xl on a 1k.

On two entirely different songs (started from scratch at two different times), I've been experiencing oddly the same issue.
After creating a bunch of tracks, I begin to get notes cutting off, seeming like it's hitting the polyphony limit; an 8 beat drone in the background, or a long reversed cymbal, or whatever.
Now I'm not unfamiliar with this limitation. I always keep track of optimizing voice usage. Setting pads to MONO, making mute groups, resampling pads that use multiple sample layers, trimming samples as short as possible, making as many samples as possible mono samples, etc.

The part that confuses me is that looking at the voice usage monitor in the OTHER screen, both songs begin to cut off voices when it hits max 18 notes used. (the number off on the side of the voice bars never exceeds 18)
Two things weird about that, it's definitely below the supposed max of 36, and somehow both songs begin to cutoff samples at the same reported polyphony usage.

I've gone through my tracks and thought about what each one is using, and 18 sounds right. I have 3 stereo audio tracks (6 voices total), 1 kick/snare track, both samples are mono, and never played simultaneously (8 total), one mono hats track (9 total) two rhythmic synth lines, mono (11 total), another synth line that uses 2 voices (13), a background droning tone, stereo (15), a mono cymbal on the beat and the pad is set to MONO (16), and stereo input thru (18 total, as the voice meter is saying).

Are there other factors which can limit the polyphony?

sciguy wrote:Are there other factors which can limit the polyphony?

Effects, doubled bpm, really anything extra that could stress the processor.

Edit: To be more specific:

sciguy wrote:...long reversed cymbal, or whatever...

Reverse would be an effect.

sciguy wrote:...and stereo input thru...

Could be a factor.

Maybe if you put in the track mute (window) Mute Type to Note On instead of Level, you will save polyphony ...

I think it's important to cut the blanks at the end of each sample too.

That tally I did of all the tracks earlier, those were every track, muted or unmuted.
The only thing I didn't mention is a muted MIDI track, which isn't related.
And I do trim off the tails of samples whenever I can.


And the polyphony, I thought that was sorta more hard-wired into the machine, not affected by other parts of the software?


I just tried playing it again after I stopped earlier, and the issue has improved for some reason. No cutting off normally, and the monitor peaks at 19.
I was able to hit some other pads and not have things cut out, until it reached 22 voices max. Still less than the expected 32 polyphony limit.
I also tried disabling the FX slots, and no change. (I'm using a reverb and a phaser).


I'm only at 120BPM.
The two songs I mentioned, one is a new version of the same song that I started from scratch mostly. The reverse cymbal is from the old one, so that's no longer relevant, but that was where I noticed this behavior on that song.
The noticeably cutting out part in the newer song is a background drone that is a sample that lasts 8 beats.

Do you have any muted audio tracks? They will count towards polyphony (unfortunately)

I just want too clarify something from your description though. Mono/Stereo is different to Mono/Poly.

Mono/Stereo is how many audio tracks are played when a sound is triggered.

Mono/Poly sets whether a sound can be overlaid with itself.
e.g. 1 mono sample can easily fill up polyphony if triggered over itself (poly).

But given that the readout says 18 voices this seems unusual.... it's not the fx though (unless there's a bug)

also - upload your project if you want too and we can check it out.

mikolo wrote:Do you have any muted audio tracks? They will count towards polyphony (unfortunately)

I just want too clarify something from your description though. Mono/Stereo is different to Mono/Poly.

Mono/Stereo is how many audio tracks are played when a sound is triggered.

Mono/Poly sets whether a sound can be overlaid with itself.
e.g. 1 mono sample can easily fill up polyphony if triggered over itself (poly).

But given that the readout says 18 voices this seems unusual.... it's not the fx though (unless there's a bug)

yeah, I know all of that.

I think that actually, every single pad in my programs is set to MONO, and I used mute groups wherever applicable.
Every sample that doesn't need to be stereo has been converted to mono.

And I know muted audio tracks use polyphony, which is why I included them in my theoretical voice usage calculation above. (at the time when I posted the original post, only one of the three mentioned audio tracks were unmuted.)

I think its bug, or something. I usually hit 18 to before cut off. FX should not be included in the voice count. Its a bit broken I think, not sure, but seeing you have same problem then I guess it might be a confirmed bug. Pretty lack lustre as it has been an issue for ages.

Me, I slice all my loops by 4 or 8 samples per bar, and I have less problems.


I made midi patterns to go with them, so it's quick to do.

MIDI has nothing to do with sample polyphony. Lets make that clear. I can stake 20 chord no probs, its nothing to do with MIDI.
For producers making beats and such from scratch, it is very annoying having such a limited polyphony. Its also pretty crappy that polyphony is not on comparison chart. We all assume that it is same polyphony, but I think it has been stripped down but hardly any one makes that many notes play at once, hence no one says anything much or even notices.
So its looks like polyphony is sacrificed for functions like pong

That's crazy, so JJOS has almost the same polyphony as an MPC60 if you use any fx? I don't see how those two things can be connected, especially to chew up sooo much polyphony. Is it just JJOS allocating processing in a shitty way?

I definitely think it is an allocation bug, and not a secret polyphony limit.

For example, on another song (I think the song I'm thinking of was from when I still used the free OS, but I'm not sure) I had experienced weird polyphony limiting. Only one track was being affected, and it was only solved by muting certain tracks, other tracks which should have also freed up enough voices did nothing. It almost seemed like it was some kind of glitch mute group.

I don't remember exactly what song it was, so I can't give more detail, but it definitely seemed like a buggy behavior and not just a lower voice limit.

A couple of things to double-check:

1. Mute Type in TRACK MUTE.
If Mute Type is set to LEVEL then DRUM programs that are muted still take up polyphony!

Change Mute Type to NOTE ON. I know pazkalin already mentioned this.

Having Mute Type set to LEVEL also makes the mpc have incredibly sloppy timing.

2. XFADE in TRIM.
XFADE in TRIM doubles the polyphony of your sample. So if you have any MONO samples with an XFADE loop on it then it will use up 2 voices. If you have a STEREO sample using XFADE then it will take up 4 voices! That's why JJ added the XFADE to FWD loop conversion - to free up that extra polyphony used.

But yeah, regardless, it still should show on your Voice Monitor in OTHER.

post up the project, i want to take a look. i've never experienced polyphony issues.

Hi, I would just solo each track and than check on voice monitor all tracks separately, but I have never experienced anything like that.