PA4X Polyphony

[Rufus]

I've noticed some notes dropping when playing my PA4X. It's been happening on occasion when I have all the backing instruments & pads playing behind me.

It sounds like it simply runs out of polyphony and can't handle all the sounds. Anybody experienced this before? Could it be some setting I have turned on or off? I'm not an expert, but I had assumed if I bought a top of the line arranger this would be a non-issue.

 

[delaware dave]

128 voices of polyphony. How its implemented by the manufacturer also factors into the equation. Kurzweil has always been known to have the best algorithm. Their approach is similar to how MP3 conversion works; notes 3db less than other notes (i.e. the softest notes) are the 1st ones dropped, so they are the least noticeable. Many manufacturers use envelope structure; Ensoniq allowd the user to prioritize the instruments to high, medium and low. Sustain pedal also will extend the notes allowing polyphony to build up and getting to the limit faster. Minimize the sustain pedal, this will give you a little more 'headroom'.

 

[Rufus]

I'm assuming the backup instruments & pads all come out of the same 'bucket' available?

In this case it's dropping the sustain on notes as I play them so it's extremely obvious. I haven't noticed it very often so perhaps there are other times it's dropping soft sounds that aren't noticeable anyway.

I believe some instruments take up more polyphony than others? I'm using Reuben's piano sounds because they're way better than the preloaded sounds but I'm wondering if it could be a factor.

 

[Biggles]

It can happen depending upon the combination of Sounds and Styles used.

Some sounds like the C5 which if I am right are resource demanding will eat up the available facilities very easily.

Having all layers active and Pads operating together can initiate the algorithm which selects and drops notes to stay within the capabilities of the Pa.

128 is pretty much the defacto standard in quality Arrangers, I am not aware of any that go anywhere near the 192 that DP’s tend to have.

Do check that your OS is up to date.

 

[delaware dave]

I believe some instruments take up more polyphony than others?

128 "Voices" of polyphony. I don't own your keyboard but if the instruments are compromised of more layers or voices then that instrument (for each note struck) uses more polyphony than an instrument compromised of less voices or layers. I would have to venture to say that your better sounding piano probably has more voices, more sampled layers. So it will use more polyphony than other instruments (per note struck). You also mentioned sustained notes are dropping; less use of the sustain pedal would help the envelope of the instrument to get to a zero level so that the polyphony is released back into the pool. All of the instruments and pads come out of the shared bucket. Many keyboards use the envelope ADSR approach (attack, decay, sustain, release). During release the polyphony returns to the "pool" as available. Pianos have a longer sustain time than some other quick hitting sounds, especially if you are using the sustain pedal to "lengthen" the sustain. Also the sustain pedal is the equivalent (for acoustic piano) of holding the note down and not releasing the note; so holding notes with your fingers even if you are not using the sustain pedal would be the equivalent to striking the note, holding down the pedal and releasing your fingers from the note; you'll get the same effect as not using the sustain pedal but striking and holding down the note, so be cognizant of this effect as well. The methodology of what notes drop first is different by manufacturer. I don't know what the philosophy was coded into the software of the PA4x and I don't want to speculate; but a pad that plays continuously in the arrangement will certainly hold polyphony longer as well as the use of the sustain pedal. Reducing the number of backing instruments and pads or reducing the length of time that those instruments are continually holding a sound will also help.

 

[delaware dave]

I'm assuming the backup instruments & pads all come out of the same 'bucket' available?

In this case it's dropping the sustain on notes as I play them so it's extremely obvious. I haven't noticed it very often so perhaps there are other times it's dropping soft sounds that aren't noticeable anyway.

I believe some instruments take up more polyphony than others? I'm using Reuben's piano sounds because they're way better than the preloaded sounds but I'm wondering if it could be a factor.

128 "Voices" of polyphony. I don't own your keyboard but if the instruments are compromised of more layers or voices then that instrument (for each note struck) uses more polyphony than an instrument compromised of less voices or layers. I would have to venture to say that your better sounding piano probably has more voices, more sampled layers. So it will use more polyphony than other instruments (per note struck). You also mentioned sustained notes are dropping; less use of the sustain pedal would help the envelope of the instrument to get to a zero level so that the polyphony is released back into the pool. All of the instruments and pads come out of the shared bucket. Many keyboards use the envelope ADSR approach (attack, decay, sustain, release). During release the polyphony returns to the "pool" as available. Pianos have a longer sustain time than some other quick hitting sounds, especially if you are using the sustain pedal to "lengthen" the sustain. Also the sustain pedal is the equivalent (for acoustic piano) of holding the note down and not releasing the note; so holding notes with your fingers even if you are not using the sustain pedal would be the equivalent to striking the note, holding down the pedal and releasing your fingers from the note; you'll get the same effect as not using the sustain pedal but striking and holding down the note, so be cognizant of this effect as well. The methodology of what notes drop first is different by manufacturer. I don't know what the philosophy was coded into the software of the PA4x and I don't want to speculate; but a pad that plays continuously in the arrangement will certainly hold polyphony longer as well as the use of the sustain pedal. Reducing the number of backing instruments and pads or reducing the length of time that those instruments are continually holding a sound will also help.

 

[Biggles]

For those reading this thread who are not used to Arrangers a bit of info

All Korg Pa arrangers and as far as I know all Yamaha equivalent models that they opertate in a similar manner.

In a typical keyboard in Style play mode with a Keyboard Split applied there are four Layers of Sounds.

Upper 1, 2 and 3 (right of split) and Lower (left of split)

Each layer can have multiple instrument sounds or it can have a single instrument sound, it all depends on what the Keyboard Set (Korg terminology) is associated with the chosen playing Style.

In a Korg a Keyboard Set it could have in Up 1 the Italian Grand, Up 2 Warm Brass and in Up 3 a Synth Pad with Lower being Movie Strings

Add in the Four Pads that could be set up to continuously so that they play a Bass Riff, a Guitar Riff, A Synth Brass Riff and a Pad riff

Add in the backing Drum track

Then you are knocking on the door of max Polyphony or even are in note throw away mode.

Then there are the Variations and Fills associated with the Style.

in a good quality Arranger there are three Intro options, preset 12 bar, user led 8 bar, quick 1 bar

Then there are the 4 Variations with Var 1 being quite light in content and Var 4 being the most dramatic.

Then there are three endings similar to the intros

So with all the Layers functioning, the Pads in use and using Var 4 they keyboard will be well loaded.

The Movie Strings that I quoted above uses 15 Oscillators and 24 in the Italian Grand which is the max available per instrument(s).

In theory the Movie Strings (or any single sound or combination) could be edited to include more instruments up to the max oscillator number

 

[Rufus]

I tried making sure to release the sustain pedal frequently but it did not help.

I didn't notice this issue until a few days ago when I started changing pads on some of the pre-set song styles. Most were changing from a single hit sound (such as crash cymbal or wind chimes) to a continuously playing pattern (such as guitar, piano, strings, or percussion).

In hindsight I think the pre-set styles are set near max polyphony. That is, for styles that are near the max with just the base instruments, I bet they assigned pads such as a one time crash cymbol that would not add to the problem. And then by changing pads I put them over the top.

Still feel a bit dissapointed this is an issue with such a high end keyboard. This must be expensive upgrade for them to increase further?

I don't feel like I'm doing anything extreme that should be pushing the limits of this keyboard yet..

EDIT - also, I'm assuming vocal processing doesn't count towards it? If you have auto harmonies and such turned on?

 

[Biggles]

The Pa4X has long been at the top of my wish list and in late 2019 I sold the Pa 700 that I had hoping that an updated 4X would happen in 2020.

After further research early last year I decided that a Pa 4X was not going to be purchased, there is no way I am spending my cash on a keyboard whose design dates back to 2014.

Korg were smart in their design and extended the life of the keyboard by the release of v3 of the OS which they termed Next, this was about March 2019 so nearly two years later and no significant revision to Next has occurred.

Next unlocked features and provided amongst other things enabled more memory to be used.

It is a bone of contention that the same type of OS update has not been forthcoming to the 700 & 1000 models both of which date back to their 2017 release and neither has had a significant OS update.

Korg is letting its Arranger customers down.

 

[Rufus]

I considered waiting for the PA5X but being quarantined this winter I decided not to wait. Overall quite happy with the 4X, but probably will upgrade as the new models come out.

I tried playing around with different instruments & pads on this particular song to see what fixed the polyphony issue - the easiest fix was changing the (2) pianos in the backing band to E Pianos. Sounds quite similar and now it works, I guess E Pianos must be less demanding.

 

[Reuben]

The Yamaha C5 Grand set I made is pretty polyphony intensive. It sometimes uses 6 or 7 Oscillators per note played.
Great if your are playing with less busy backing for sympathetic resonance and key on/off effects etc., but for very busy backing I would recommend this:
Go to Sound Mode, select Piano sound, Menu, Sound Basic and reduce Ocillator count to 12 (if you want just the stereo piano samples) or down to 14 (if you still want to include basic resonance), then save the sound to a new User Location and use this instead. This will free up a fair amount of polyphony.

 

[Rufus]

Thanks Reuben! I actually prefer Bright Piano 3, it's my default setting. Tried following your recommendation and it looks like it uses 22 oscillators (not sure what that means, I should probably do more research)? I turned it down to 14. Can hear a slight difference but still sounds great. Will try it with a few song styles and see if it helps with the polyphony issue.

 

[OldTimerBill]

The Pa4X has long been at the top of my wish list and in late 2019 I sold the Pa 700 that I had hoping that an updated 4X would happen in 2020.

After further research early last year I decided that a Pa 4X was not going to be purchased, there is no way I am spending my cash on a keyboard whose design dates back to 2014.

Korg were smart in their design and extended the life of the keyboard by the release of v3 of the OS which they termed Next, this was about March 2019 so nearly two years later and no significant revision to Next has occurred.

Next unlocked features and provided amongst other things enabled more memory to be used.

It is a bone of contention that the same type of OS update has not been forthcoming to the 700 & 1000 models both of which date back to their 2017 release and neither has had a significant OS update.

Korg is letting its Arranger customers down.

Hi Colin ... if I am reading this correctly, it looks like you don’t currently own an arranger keyboard. I am in the market for one (the PA700 is probably at the top of my budget). Which arranger keyboard do you (or anyone else) recommend?

 

[OldTimerBill]

Just as an aside, the elusive Medeli AKX10 claims to have 256 notes of polyphony. This is based on the fact that this keyboard isn’t available. If it ever becomes available, Medeli might reduce the number.