I'm pretty new to pd and I love it!
I have started to program my own synth that is based on a synthpatch from the internet. I've modified it to my needs (added a choice for waveforms, attack/decay and the possibility to add noise to the signal).
Now here's the problem:
I'm sure all of you will have realised that I'm adding up several signals of osc~. The problem - obviously - is that they are too loud when they add up. So is there any solution than reducing the signal so much that it's very quiet when you hit just one key and it's just loud enough if you hit six notes at once.
I hope to find a way to reduce the maximum output with every note that I hit and increase it with every note I release.
Any ideas?

http://www.pdpatchrepo.info/hurleur/voicing.pd

There are many ways to calculate this, a common one is to multiply the gain with 1/sqrt(nr of voices).

How would I do this?

you have to keep track on how many notes are playing...see attached.

http://www.pdpatchrepo.info/hurleur/poly-gain.pd

I wonder if this is really the way to do it? You only take into account note-on and note-off values but this tells nothing about the actual state of a voice when there's an amplitude envelope (e.g. with simple attack and release). Imagine you play a 4 note chord with a long release, as soon as the note-off values are received won't this make the release part of the chord suddenly a lot louder?

You could add one to the number of voices. That would leave the gain at one, when the last note is released.

I don't think this is necessary because if you play all the voices available at once and the gain is reduced in the way pulsed said you can play another voice and one of the voices you've already played will vanish. There is no chance in this synth to add more than 6 voices by using the decay time so far (and I don't think I will incorporate that.
Steffen, thank you for the idea. I will incorporate that!!!
Happy new year! ! !

...well it did work but caused a quite listenable attack whenever you hit a note. Anyway, in combination with a slight compression it now sounds fantastic! Thank you.
Another thing I would like to add is the chance to save a preset. Is there a chance to save some of the things I do into a list (e.g. the values for my moog filter and the bandpass)?
Here's the complete patch so far.

http://www.pdpatchrepo.info/hurleur/Synth_V4_8.pd

By the way...
the compressor is this one: http://twobigears.com/labs/a-compressor-for-pure-data-libpd/
It's quite nice and usable!