Three zones for diy E cymbals

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Three zones for diy E cymbals

Postby ignotus » Tue Feb 12, 2013 11:43 pm

For quite some time I've been looking at how to get 3 zones on my A to E cymbals, specifically my ride. I only really need 1 zone for crashes (with choke, but not for a 2nd zone), but I think rides are a different story - I suppose it would depend on your playing style, but while i just tend to "crash" crashes, I like to make use of the versatility a ride can give you with its edge, bow and bell sounds. I daresay this is the case for many drummers and is illustrated by the fact that e.g. Addictive Drums only has one articulation for crashes (+ choke) and a wide range of them for the ride.

Ok, so we have the piezo/piezo/switch and the piezo/switch/switch approaches. My beef is with the switch part. Fitting a switch on top of an acoustic cymbal is quite tricky, ugly as hell and prone to failure after some time. Switches just for the purpose of choking are another matter and are easily done underneath the cymbal - you can hardly see them, they don't need to withstand constant beating and they don't need to be sensitive to light hits or anything else. I know MD can -in theory- do positional sensing on the ride input, but as far as I know, no one has managed to use it in practice. I gave it a go and it was just all over the place. I don't have the rectifier circuit but I have managed to *kind of* get positional sensing working on the snare input (it changes too suddenly from centre to rim but at least it's more or less on track). I may be wrong but my guess is that it's because this feature has been coded with mesh heads with centrally placed piezos in mind, and the vibration of cymbals is completely different. So, this got me thinking about how we could get 3 zones out of our DIY ride without messy, clunky switches on top. This design would lack a choke, but how many of us choke their ride? What follows may be a total load of nonsense, and if so I humbly apologise in advance for making you read through such a lengthy piece of BS... but anyway, here goes... *drumroll*...:

Would it not be possible to distinguish between edge, bow and bell using two piezos? I'll explain.

Piezo 1 is located near the edge and piezo 2 in, or close to, the bell. First we'd calibrate a midpoint; we strike the cymbal halfway between the bell and edge and tell the module: "this is the halfway point between both piezos: bow note". They don't have to receive an equal signal strength, because from this point on we'd be working with signal ratios. For the sake of simplicity, let's say the ratio at this midpoint is 1/1. This means that a strike with force 100 on piezo 1 also has a force of 100 on piezo 2. As we move towards the edge, a strike with force 100 on piezo 1 would have a force of, say, 70 on piezo 2, giving a ratio of 10/7, and so on. Moving from the midpoint towards the bell would have a similar effect, but with the ratios reversed. So, all we need are two ratio thresholds from which an edge or bell note are triggered, and the values in between that are for the bow note.

I don't know if this is doable at all firmware-wise, and maybe Dmitri has already considered and discarded it as a bird-brained idea, but anyhoo, there it is for your consideration...
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Re: Three zones for diy E cymbals

Postby dmitri » Tue Feb 12, 2013 11:55 pm

ignotus wrote:Would it not be possible to distinguish between edge, bow and bell using two piezos? I'll explain.

Piezo 1 is located near the edge and piezo 2 in, or close to, the bell. First we'd calibrate a midpoint; we strike the cymbal halfway between the bell and edge and tell the module: "this is the halfway point between both piezos: bow note". They don't have to receive an equal signal strength, because from this point on we'd be working with signal ratios. For the sake of simplicity, let's say the ratio at this midpoint is 1/1. This means that a strike with force 100 on piezo 1 also has a force of 100 on piezo 2. As we move towards the edge, a strike with force 100 on piezo 1 would have a force of, say, 70 on piezo 2, giving a ratio of 10/7, and so on. Moving from the midpoint towards the bell would have a similar effect, but with the ratios reversed. So, all we need are two ratio thresholds from which an edge or bell note are triggered, and the values in between that are for the bow note.

I don't know if this is doable at all firmware-wise, and maybe Dmitri has already considered and discarded it as a bird-brained idea, but anyhoo, there it is for your consideration...

The signal difference from two piezos on the same surface will be almost the same regardless of where you strike this surface unless this surface strongly suppress sound/vibration propagation through the plane of this surface.
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Re: Three zones for diy E cymbals

Postby ignotus » Wed Feb 13, 2013 12:46 pm

dmitri wrote:The signal difference from two piezos on the same surface will be almost the same regardless of where you strike this surface unless this surface strongly suppress sound/vibration propagation through the plane of this surface.
I see what you mean; the problem is, to make what I describe in my previous post possible, there needs to be some kind of interaction between the piezos, which won't work if they're isolated. The thing is, I'm able to get perfect zone separation between bell and bow with a piezo in each. But if I disconnect the bow input and strike the edge, I get a soft bell hit, with similar results in the bow when I disconnect the bell and strike it. I suppose the thing to do would be to set dual head to 'no' and have a look at the midi values from each input as I move the strikes around the surface.
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Re: Three zones for diy E cymbals

Postby airflamesred » Wed Feb 13, 2013 11:44 pm

As a matter of interest Ignotus, and bear in mind I'm just thinking outside the box here, Is there a real need for the 3 zone cymbal? I'm thinking the e cymbal can be re-designed some way.

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Re: Three zones for diy E cymbals

Postby everson » Thu Feb 14, 2013 8:40 am

I think the megadrummers don`t really need it. We have lots of inputs and could make it using 2-3 inputs/cymbals, which is more comfortable and reliable ...
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Re: Three zones for diy E cymbals

Postby ignotus » Thu Feb 14, 2013 7:36 pm

airflamesred wrote:Is there a real need for the 3 zone cymbal?
You're right, there isn't a pressing *need* for 3-zone cymbals - as I said I would only really use such a feature on my ride, as I'm happy enough with the rest just being single-zone, but I thought it would be nice if there was a way to DIY a 3-zone cymbal by just using a couple of piezos instead of complicated and messy homemade switches. What's not to like? Of course, it would be dependent first of all on whether it is actually doable and then if so whether others would use such a feature; (wishful) thinking aloud if you like ;).
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Re: Three zones for diy E cymbals

Postby ibanman555 » Fri Feb 15, 2013 12:33 am

I for one really appreciate this idea, and I can see what your plans are with it. I would also find this useful, as my current ride only allows for Bell and Bow. Depending on the software you use, this is already something that is doable with a Dual Piezo configuration.

I am operating with Superior Drummer 2, and this program allows for MIDI-Nodes, which in essence will allow you to do exactly what your thinking. Theoretically you can use this option to play Bell, Bow and Edge with Dual Piezo setup. Here is a quick demonstration of this feature...

http://www.toontrack.com/tv.asp?channel ... s&item=146

With this setup you could setup the accomplish this idea. You could even integrate a choke and have Bell, Bow, Edge and choke for a ride cymbal (not seeing choke for Ride common). It all depends on the sensitivity of each Piezo as far as velocity is concerned (you may need to isolate as Dmitri stated). You could set an equal velocity for both Piezos to achieve a Bow sound, Bell separately and Edge separately. I hope I'm not speaking to confuse, but this is totally possible with the correct setup.
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Re: Three zones for diy E cymbals

Postby ignotus » Fri Feb 15, 2013 10:01 am

@ibanman555

Have you tried setting up your dual piezo cymbal to get three zones in Superior Drummer? Does it work? Maybe I missed something, but from the explanation about midi nodes in the video, my understanding is that you can get velocity-dependent notes on each piezo, but the idea here would be to make the notes ratio-dependent - a result of the way both piezos interact with each other.

I haven't yet had time to get down to it (one-year-old babies tend to consume all your available time..), but I want to see what happens with dual pad set to 'no', striking from edge to bell with varying forces and seeing what midi output there is from each piezo. It would be interesting if different strike forces yielded similar ratios in the same area of the cymbal, and if these ratios varied consistently as you moved across it. I know, a lot of 'ifs', but worth looking into I think.
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Re: Three zones for diy E cymbals

Postby ignotus » Fri Feb 15, 2013 12:42 pm

Well, I found some time to check this out, and the results look encouraging.

I set dual pad to 'no' and looked at what each piezo outputs with soft, medium and hard hits on the edge, bow and bell.

The first value in each pair corresponds to the edge piezo, and the second to the bell one. Of course its impossible to get exactly the same values twice, but these are averages:

Soft hits:

Edge-------------Bow----------Bell
3/1---------------5/4-----------2/10

Medium:

Edge-----------Bow------------Bell
60/5-----------50/55----------8/50

Hard:
Edge------------Bow-------------Bell
100/10--------90/100----------40/127

As you can see, the ratios seem quite consistent. Anything above a 2/1 ratio could be an edge hit, anything above 1/2 a bell and everything in between the bow. This test was done with a 14" hi hat cymbal heavily dampened with pvc on the bottom. What would be really good is if anyone else with a dual piezo cymbal could chip in and see what values they get.
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Re: Three zones for diy E cymbals

Postby everson » Fri Feb 15, 2013 6:55 pm

Wow, that would be amazing if this could be worked out!
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