[linux-audio-dev] Re: Software controller for homemade edrums

[Olivier Guilyardi]

Hi Lachlan,

Lachlan Davison wrote:
>>Assembling piezo microphones, cardboard, foam, wood and a cymbal stand,
>>I have just made my first DIY electronic pads. Actually it's electronic
>>percussions, because I will play these mostly with hands.
>>
> 
> Hi,
> There will be a lot of developments in smack in the coming months on modeling hand drums and i think you might get some good results with your triggers and smack. You can also try pluggin the audio out of your triggers and the excitation signal for the physical modeling drums in smack. This would allow you to get a level of control that is very difficult with midi/osc in that it directly uses the attack/release/velocity etc of your triggers in the sound.
> 
> Give me a yell if you want a hand with using them like that, as i'd love the testing. 

I'm a bit lost now... There seem to be many opinions on how to use these pads. 
I'm usually not really into synthetizing/modeling, more into using samples. But 
I've been told that using a convolution engine as BruteFIR I could be able to 
apply the signature of any sound to the raw signal that comes out of the pad.

With this convolution approach, no need to "trigger" anything anymore, just use 
the signal as it is, and run it through the convolution engine. But BruteFIR 
seems like a complex tool, and I currently have no knowledge about so-called 
convolution.

If Smack is part of your thesis, as I read on your website, I'd recommend that 
you build some pads, similar to mine. This way you should be able to tune Smack 
much easier, so that it becomes a more giggable tool, using the pads.

Once you get this working, just drop me a mail so that I give it a try, from a 
drummer point of view.

All that said, I must confess that I still believe that triggering is the only 
real choice according to my needs. This would need such settings as 
gain/xtalk/threshold in order to correctly convert the raw pad signal into a 
such "trigger" event. This may be much harder to achieve than it sounds (1).

And I now think that this trigger-detection engine should indeed output midi, so 
that you can plug into many different devices/applications. Now, once a midi 
signal is issued, and ends up playing a sample or synthetizing a sound, nothing 
forbids to further exploitate the original signal, as in the following diagram :

pad signal -----> trigger to midi conversion -----> sampler/expander
     |                                                      |
     |                                                      |
     +-----------------------> effect filter <--------------+
                                  |
                                  +----> final sound

The "sample/expander" could either be a sampler as Specimen, or a synthetizer as 
Smack.

Then, the "effect filter", could reuse the original pad signal form and 
caracteristics in order to alter what's coming out of the "sampler/expander". 
Velocity may happen at the midi level, but other complex caracteristics that are 
carried buy the original signal pad could be fed into a convolution engine,
into some dedicated Smack routines, or even into some LADSPA plugin.

I'm not sure about all of this, just ideas for now... While these ideas get more 
precise, I may buy myself some Roland/Alesis dedicated hardware, with some 
effect pedal in order to actually do music ;-)

References :
(1) See the Alesis DM-5 manual, section "About trigger parameters", page 40 : 
http://www.alesis.com/downloads/manuals/DM5_Manual.pdf

--
   og