Hi all,

I found a Csound patch synthesizing sounds for a handpan on this page and it sounds great.
I then wanted to interface it with my MIDI controller so that rather than learning Csound from scratch, I've embedded the CSD synth into a Pd patch using the [csound6~] external. Works great.
The next steps however were to use such Pd patch on my smartphone via MobMuPlat, or in a DAW using plugdata (my attempt at generating a VST with Cabbage shows very poor CPU performance), however both are based on libpd and don't support [csound6~].

So I've taken the approach of reproducing the csound patch in vanilla Pd, which was very instructive. I've followed the same variable, function names and logic, read a lot of documentation, and came up with the patch attached.
handpan_comparison_csd_pd.zip

However, the sound is not quite the same. There is a huge lot of high frequencies in the Pd version, which I couldn't quite eliminate even using up to 10 successive [lop~ 900] (I've left only one in the patch for now), but more generally I can't figure which differences between the csound patch and the patch may have this effect. Note that I am neither an expert in Csound or in filters - in particular I don't quite trust the Butterworth3 filter I hacked together - can I even realistically expect that the same algorithmic logic in Csound and Pd would produce the exact same sound?

So I'm now asking here for help, in case some experts may find the time to review what I've done in Pd and compare it with the Csound patch, and may be able to suggest improvements. I know it is quite tedious work but I am hopeful Thanks in advance to anyone who gives it a try!

(Note that this patch was embedded in a more complicated one including interfacing with the midi controller, definition of various scales, debugging/monitoring etc., which I've removed before sharing it here, but I may have forgotten some bits here and there, let me know if it complicates the review!)

@zigmhount I am guessing iPhone? If not there is a csound Andriod app if you are not aware of it. I have never had much luck converting csound stuff to pd even on fairly simple patches, never seem to sound as good and sometimes sound nothing alike despite my best efforts. I don't have time to figure out your patch right now but the first thing I would do as a test is break it down into the three component sounds, finger strike, tine, and resonator and compare them individually, would help in identifying the problem.

Thanks @oid for your reply. Actually I'm on Android, didn't have much success with Cabbage for Android and I believe I tried csound on Android, I can't really recall but it must have been disappointing because it's not installed anymore Anyway, MobMuPlat was pretty cool to also design the UI with PD's objects. That was a year ago though, today I want to use it in a DAW (on Linux).

the first thing I would do as a test is break it down into the three component sounds, finger strike, tine, and resonator and compare them individually, would help in identifying the problem.

I actually did this at the time, thanks for reminding me. I compared the signals between Pd and Csound in an analyzer for all members and combinations:

• Strike:
  • aNoise
  • aTone
• Tine
  • aFundamental (I had to add *~ 3000 to the signal, but could not figure out why...)
  • aBeat (also *~ 3000)
  • aHarmonic
  • aReso
  • aHi
• Resonator: that's where it starts looking bad
  • aTone1 was not great
  • aTone2 was kinda ok
  • aTone3 was terrible

As far as I can recall and understand from these year-old screenshots (I should do it again), anything but the tonal sound (300-400Hz) was pretty much inexistent, and the tweaks I tried to add some power below 300Hz and above 600Hz (added a shelf using [rzero~] and [rpole~]) lead to strong harmonics, which causes the high-frequency sounds I hear when playing the patch I shared above. My conclusion at the time was thus that:

"Somehow the resonator's lpbutt and hpbutt let many high freq through in CSound compared to [butterworth3~] in Pd, don't know why, but I'll just continue with that for now:"

I'll try to investigate the Resonator again.

That said, your comment

I have never had much luck converting csound stuff to pd even on fairly simple patches, never seem to sound as good and sometimes sound nothing alike despite my best efforts.

tends to motivate me to work instead on the Cabbage plugin version of the csd patch and try to improve its performance (right now it uses a full core of my CPU regardless whether or not it plays notes). Csound forums, here I come!

@zigmhount said:

tends to motivate me to work instead on the Cabbage plugin version of the csd patch and try to improve its performance (right now it uses a full core of my CPU regardless whether or not it plays notes).

It is perfectly possible that it is just my failing, I am not great with pd audio and mostly use it for control. I have made the attempt to go pure pd more than once but have resigned myself to csound and pd. From what I understand Cabbage is just JUCE+csoundAPI so should not be much more resource intensive than the [csound6~] external, so maybe you just made an error somewhere when you tested it out? or found a bug with a known (hopefully) workaround?