Multiple zones with just two piezos

[ddriver]

Hi Dmitri, first of all congrats on the great project, it is so good to know there are still people like you amidst all the commercial greed and expressive yet inferior crap it produces. I am looking towards ordering a 56 input kit next month but before that I have a question for you.

Here is a diagram of what I have in mind:



So the idea is simple, the pads are not circle, but a pipe that goes only along the X axis, the rubber is pretty stiff in order to distribute stress nicely along the entire length of the pad, thus impacts will always be distributed proportionally to where they are along X - it should be fairly easy to calculate the position of impact with sufficient accuracy, and dynamics won't cause detection issues since it is an issue of the ratio or differential between signal levels, not the actual levels - meaning no unwanted bleed at all... since it won't be bleed, the bleed will be what ends up being used to determine hit position.

My question - Is it possible to assign multiple zones, for example on the snare, I'd like a ring zone from 0-5%, from 5-25% - rim, 25-75% - head, 75-95% rim again and finally 95-100% - again ring, three zones but 5 instances?

Or lets say I don't need symmetry I can simply assign 3 different zones, for example 0-30% - choke, 30-60% - bell, 60-100% crash - three zones three instances

So that is it basically, plus another short question, I have downloaded the megadrum editor software and I noticed names as well as the inputs themselves are pre-configured, is it possible to create unique names for our instruments, and also change they way channels are interpreted, for example I noticed only channel 1 is a mono kick, all other channels are stereo head/rim, is it possible to chose which channels are mono and which stereo, since my scenario of use requires more mono channels?

[dmitri]

My question - Is it possible to assign multiple zones, for example on the snare, I'd like a ring zone from 0-5%, from 5-25% - rim, 25-75% - head, 75-95% rim again and finally 95-100% - again ring, three zones but 5 instances?

Or lets say I don't need symmetry I can simply assign 3 different zones, for example 0-30% - choke, 30-60% - bell, 60-100% crash - three zones three instances

First of all, it is not that simple. I may look at it in the future if there is a demand for this. No promises.

So that is it basically, plus another short question, I have downloaded the megadrum editor software and I noticed names as well as the inputs themselves are pre-configured, is it possible to create unique names for our instruments,

Very likely I will implement this.

and also change they way channels are interpreted, for example I noticed only channel 1 is a mono kick, all other channels are stereo head/rim, is it possible to chose which channels are mono and which stereo, since my scenario of use requires more mono channels?

All stereo inputs can be used as two independent mono inputs.

[ddriver]

I am not familiar with the Atmega chip and its capabilities, I myself have done only some basic c++ stuff, and chances are it could be easier to realize my idea on the pc, sort of receive two notes from the two zones and calculate the differential in their velocities, and generate as many notes/zones from it as necessary, but it will require a PC, and if rerouted to a drum module will probably increase overall latency a bit aside from reducing reliability.

BTW, I wonder has anyone measured the latency of the megadrum, approximately how many msec it takes from the actual hit to receiving the midi note through USB on the PC?

[dmitri]

viewtopic.php?p=18036#p18036

[ddriver]

From your link I assume the processing latency of the megadrum is 4.5 msec, which is pretty good, but seeing how it stacks with the rest, is there some way of eliminating the 14 msec usb->midi latency. The USB interface itself is reported to have 1000 usec or 1 msec latency so it is hardly the bottleneck of performance.

I play technical death metal and many of the notes I play reach below 60 msec (like 16th at ~260BMP) and latency approaching 20 msec would result in 30+% offset, which is rather annoying.

[dmitri]

From your link I assume the processing latency of the megadrum is 4.5 msec, which is pretty good, but seeing how it stacks with the rest, is there some way of eliminating the 14 msec usb->midi latency.

It is not USB->Sound latency not USB->MIDI.

1. A faster computer.
2. A faster sound card.
3. Not forget that it takes 3.3ms for sound to travel 1 meter.

[ddriver]

I meant 4.4 msec for the megadrum hardware alone, about the same - half from asio latency, or about 4.5 for output latency, so the rest is software latency - abou 10 msec of it, most of which I assume comes from translating from usb to midi and from the actual VST instruments

I am running a dell n7010 with a 2.66 GHz i5, with the turbo boosting it to 3.2 GHz, 6 gigs of ram, it is a decent machine I guess, and with the Toneport UX8 I get 9 msec total latency and about 4.5 msec output latency, so it would be technically possible to get 10 msec latency if it wasn't for the USB->MIDI driver latency penalty and sampler software

I suppose if using a drum module with the midi output of the megadrum latency should be much lower compared to using USB and software samplers?

[kupooglop]

(like 16th at ~260BMP)

a properly setup megadrum using a decent trigger can do this with no problem. I trigger a drum machine, a hardware sampler, and synths through midi port. No software stuff through usb. I play similar music with no latency issues.

[ddriver]

Nice to hear this

[dmitri]

and with the Toneport UX8 I get 9 msec total latency and about 4.5 msec output latency, so it would be technically possible to get 10 msec latency

I don't quite get what latencies you are referring to and how you measured them.

if it wasn't for the USB->MIDI driver latency penalty and sampler software

What USB->MIDI driver latency you are talking about and how did you calculate that there is that penalty?