Hi,

First post, but I have been using Pd for the last year and it is no overstatement to say it has changed my life. I just presented a piece at the ICMC here in New York that was based around a neural-like patch written entirely in Pd. Now I am getting ready to teach a basic music class to 8-14yr olds in a summer camp type atmosphere.

The question is:

is it possible to create the equivalent of 20 individual keyboards (or really, 20 of any cheap kind of simple interface will do) to be used by all the students at once, using headphones that allow them to hear only what they are doing (or an arbitrary number of other people besides themselves), but without using separate computers? The school has virtually no budget, no usable keyboards, and I have only my one laptop, with the one soundcard.

I guess I will have to start using the "use multiple devices" setting in the MIDI preferences. But this would seem to require at least two pieces of hardware beyond the 20 or so keyboard-like devices and headphones (with my present computer as sort of the "server"): one to receive all the MIDI-or-otherwise data, and one to separate all the individual audiostreams going back to the headphones.

I imagine some Pduino-type device will be necessary, but the real question that I just began thinking about is essentially how to deal with having only one dac~ object.

Any suggestions would be greatly appreciated. I am giving a brief presentation to parents on Thursday and would love to know what I'm going to say!

If I can't figure it out, I still plan on using Pd somehow, but the class is just going to have to do a big group singalong instead. Yikes.

Thanks

You should be able to daisy chain MIDI keyboards using the Thru inputs. If each one is on a separate MIDI channel then you should be able to have sixteen keyboards connect to one MIDI input on your computer. You could use a MIDI to USB converter if you need it (most MIDI keyboards these days should have a USB out, though). So if you have two USB ports, that should be enough. Also, if you have keyboards with a wide enough range, you might be able to save a few bucks and just split the keyboard in Pd via [moses] so one kid plays on the low keys and another plays on the highs. Or maybe you can find a creative way to have one play the keys while the other fiddles the knobs/sliders.

I don't really know the best way of getting 20 headphone outs without using an expensive headphone distribution amp. Maybe someone else has an idea there. But as far as [dac~] is concerned, you can give it arguments for each output. So [dac~ 1 2 3 4] will create four inlets corresponding to the first four audio output channels.

yep. 'fraid, if you want 20 different output signals, you'll need 20 output channels on your audio interface.

if you only want the kids to hear themselves, there might be a headphone jack on each keyboard?

Thanks, guys. I realized that getting MIDI data into the computer is not the hardest/most expensive part. The issue clearly is audio output, which in this case is complicated by the fact that they can't provide even the simplest MIDI keyboards, from which to, say, get individual headphone feeds. (A check of the few keyboards they do have seems likely to reveal not more than one or two actually MIDI-enabled ones- just old school, 128 cheap sounds Casio-type)

I haven't quite figured out what configuring multiple audio channels entails. I guess it requires more complex DAW hardware than just a headphone out jack, or even a basic MIDI interface with line out and headphone out. Maybe a dumb question but where would channels 3 and 4 of [dac~ 1 2 3 4] "go"? That is, what physically do they correspond to? Are there some tutorials on ways to send one big packet of audio out of Pd and split it after the fact via a mixer or something? I have an old Protools Digi 001 serial interface that may have had more than one channel out, but really have no idea how to hook that up to Pd. And I guess 16+ channels out would require even more expensive gear, like a big ass studio mixing board, or perhaps something like the Digi 002 Firewire board.

The best thing really would to scare up the cheapest MIDI keyboards the internet has to offer. Haven't really been keeping up on that. I need me a philanthropic organization!

Thanks again for your suggestions. Please let me know if you have any further thoughts.

Perhaps this post belongs in the Hardware section! Whoops!

3 and 4 of [dac~ 1 2 3 4] would just go to channels 3 and 4 of your audio interface. Obviously, if you're only working with a stereo output, then you won't have those channels to work with.

yes your biggest problem is getting the audio out to seperate chanels. the patching in pd~ should be fairly easy, the pb is the hardware: you will need a soundcard with various outputs (MOTU or something, the digidesign ones are out of price) and that's quite expensive (around 1200 euros for 8in/8out) profesional stuff ... if you do chose that option i could help you with the installation and the patching.

yes maybe having them control diferent sounds in layers or something, or using all the scalars and gem to have it visual ? multichanel playing still isn't democratic ....