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Home DIY Electronic Drums X4L eDrum Trigger X4L Mylar Refection Plate (Update)

X4L Mylar Refection Plate (Update)

The following was originally posted by Hellfire over at Vdrums.com:

Most people when they get into DIY edrumming for the first time, they tend to use the Remo practice pad conversion.  Split the foam in half, attach a piezo to a metal plate of some kind, and sandwich it between the foam halves.  That works OK, (rolls and flams suffer a bit) but for my way to work I need a little more shell depth.  Well, my X4L has that depth.  The system has four layers.
Layers #1 & #2 – 1″ thick Poly-fil batting
Layer #3 – mylar disk (yes the same as a drum head) with one 27-mm piezo attached to the bottom with 3M chemical resistant double stick tape.
Layer #4 –  1″ thick Poly-fil batting
This is placed under a mesh head.

I know what you are thinking, you’re thinking “The piezo wouldn’t last 1 hour”, but you would be surprised at just how well it works.  I’ve even road tested already.  (yes, I gig out).  This system is much more sensitive than the old foam-metal-foam style, and it seems it trigger just as good as my Roland cone drums. I most also say that it doesn’t feel like you are hitting a foamed back drum trigger.  I think most of us here know that hitting a edrum that has foam behind the head just “feels” bad.  It looses the bounce and has a bad thud. My new sensing system does not feel like you are hitting foam, because you aren’t.  Poly-fil is a lot less dense than foam, this is why I use a mylar disk instead of metal. The Poly-fil also, does not dampen the bounce as severally as foam.  The end result of using a mesh head with my new system really does give you the feeling you are playing on an acoustic drum. You still have bounce, but it is not like a trampoline, it is more like a mylar head.

In the pictures you will notice that I had to retro-fit my X4L.  I couldn’t have anything in the cake pan because of how close the mylar sensing plate sits to the bottom of the pan, so I ran the wire out the bottom into a project box.  Here’s some pictures:

Well, there it is.  I hope people try there own experiments with this system so I am not the only one who knows how good it is.  eDrumming for me is one big experiment, so I am always changing, tweeking, and messing with my designs.

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19 Comments  comments 

19 Responses

  1. manapa99

    hi, im currently in the middle of my first A/E project. I am looking at possibly scrapping that idea to try this instead. Space and sound are going to be a big issue for me in the near future and my acoustic set just isn’t going to be able to come with me.
    I mainly was wondering how well this would work for the alesis trigger I/O and if just adding a separate piezo to the side of the pan would give me a rim sound option, or would there have to be a section that is batting free to help separate the signals?
    Thank you so much for your hard work and time spent! im just getting in to this and i really appreciate the information!!

  2. L_Tuck

    I’ve built four of these trigger pads. One for a snare, and three for toms. They look great, thanks for the design. I’m sending them into a Megadrum 32 channel trigger to MIDI box I built myself. I then send the MIDI into an Alesis SR16 for the drum sounds.
    Cool design. I’m still tweeking mine too. Adding different amounts of padding, different reflector plates, …
    Thanks again.

  3. Sounds good. If you ever wish to upgrade your SR16, I would highly recommend the Alesis SR18. I used it myself with a Trigger I/O kit. very similar set-up to yours.

  4. kb9jlo

    Phil, I saw on edrumforum.com something about using pie plates? Is that just a pie plate in place of using the cake pan?
    Do you still use the piezo on the pan itself for rim pickup?
    Do you put foam or something under the plate itself?
    Do you think any self supporting clear plastic would work — thinking of thin clear plastic used in disposable food containers?
    I too am in the process of building the Megadrum trigger to USB-MIDI. I’ve ordered all the parts. Then going to use something on a laptop as the drum module.
    I’m definitely building one of these as a snare. Don’t know what I’ll do for all the toms yet. I already have a 10″ hoop picked up from a local music store.

  5. You should be able to use either a cake pan or a metal pie plate. The difference is going to be the depth of the pan/plate. If you plan on using the clear plastic in the same way I’m using it here with the X4L, I would say no it will not work. That is because the pan/plate is used as a very shallow drum shell which the head gets stretched over. That kind of tension would crush a plastic container (unless it is really thick, like maybe a 1/4″ thick). I hope that helps.

  6. kb9jlo

    If I’ve double posted sorry… :-)
    The plastic I was talking about was for the reflection plate, not the ‘structure’ — for that I’ll use a cake pan. The plastic I was talking about is slightly rigid, self supporting. When you buy some baked goods (cakes, pies, cookies) like at Wal-mart they come in those snap apart plastic containers. I was thinking of using a clear plastic lid as my reflection plate.
    One more question, do you use a piezo on the cake plate with this arrangement? And do you put it in the center? (okay two questions)
    I’ve got the Megadrum PC boards etched and I’m stuffing parts. This weekend I’m putting together my snare drum.
    You’re right, this is fun!

  7. A piezo on the cake pan would serve as the rim sensor and yes it would be in the center of the pan.

  8. kb9jlo

    Phil, I’ve made my drum (FINALLY). Don’t quite have anything to hook it too but I’m working on that.
    For the reflection plate I used a disposable plastic dinner plate – you know a plastic version of a paper plate.
    I hooked the outputs to a scope to “see” what it looked like. It works. Seems that the rim trigger has more raw output but I would suppose that to be normal since there is more of a “direct” connection between a rim shot and the piezo in the bottom of the cake pan.
    The reflection plate piezo waveform “looks” just like all the classic pictures of what the output should look like.
    I’ll let you know more when I get a ‘brain’ to hook it up to. Right now I’m trying to get a Microdrum project off the ground.
    — Dan

  9. dajich

    Hi, i build 2 days ago a butter cookie tin edrum and added your idea of mylar reflection plate, i have built many edrums and none of them works decently, they always have little sensitivity and high hot spot (maybe i need too much detail).

    When i was cutting the Mylar disc, i thought, mmm i don’t think this gonna make it, it really works!, it needs a high amount of preamp but, it is very sensitive, i can make snare rolls, I’m still having some issues with unwanted notes when i hit it very hard, but the problem is my edrum brain, it’s a home made self-designed, still needs code debug, I’m a bass player but recently i feel the urge of learning to play drums.

    By the way, merry Christmas, sorry for the bad grammar, not a native English speaker.

  10. Sounds good, thanks for your comments. Let us know if you get the unwanted notes issue resolved. Again, thanks for your comment.

  11. travis

    How well does this design work for responding to dynamics?

  12. It worked well for me. It really depends on how you make it. You may need to experiment with different amounts of ploy-fil. I hope that helps.

  13. Andre

    Hi Phil, Awesome design. Well done. I’m in the process of building my fist drum. Do you or anyone of your e-drum buddies have any advice on the best size and frequency range peizo to use. It seems there are a variety of piezos out there and I wonder if this effects the sensitivity at all, or is it not enough to worry about. Thanks. Will keep you posted on my progress.

  14. I tend to stick to 27mm size piezo elements. I found the frequency range isn’t all that critical. I’ve used piezo elements as small as 15mm, but I would stay in the 20-27mm range. I hope that helps.

  15. M1234

    Great idea, thanks for sharing!
    I have built this with great success yesterday (though in a slightly different way) for an A to E conversion. My reflection plate was a complete drumhead (including its rim), 2″ smaller than the drum. This head rests on some layers of polyfil discs, supported by a plywood disc held by three l-brackets. The drumhead has the piezo attached to it with double sided tape. And a few layers of poly-fil on top, plus the mesh head.
    So I my sandwich is plywood, poly-fil, drumhead with piezo, poly-fil, mesh head.
    Works great, though I had to adjust my Trigger IO to avoid double triggering. The sensitivity is wonderful.
    The only problem I still have is that even if I use the Log4 or the Offset curve, the feel is still a bit exponential. It is hard to make a difference between medium and strong hits when playing. For example when playing a medium velocity single stroke roll some notes will come out with max velocity, even though they’re played only very slightly stronger. Any ideas on that?

  16. Thanks for the comments. I put additional thoughts on your issue over at http://www.DMdrummer.com as there was a similar question posted. Here’s the link: Log4 curve not enough

  17. Freddy Shimabukuro

    Hello Phil,

    First of all, I must congratulate you and thank you for making this great step by step tutorial. You’re kind of encouraging me to build my own triggers. I wanted to ask you something before I start building them.

    I’ve seen in other tutorials that instead of the mylar disk, people tend to use mouse pads. Some of them even say it is a resistent material. Would you recommend this as well? I mean in terms of how responsive the trigger will be.



  18. Hi Freddy,

    The mylar disk is used as the reflection (or sensor) plate. I’ve never seen anyone use a mouse pad for this purpose. I have seen people who have used the mouse pad as a striking surface on top of a solid plate. That tends to work well for many people.


  19. Johannes

    Hi Phil,

    i really love the mylar-as-a-reflection plate idea, seeing that i have the suitable mylar discs already at hand because i cut out cheap mylar heads to use the outer part (the metal ring also cut off) to put under the mesh-heads to protect the drums bearing edges.
    I would be glad if you could help me out with a couple of questions (some might just be european-specific…)

    – What is the depth of those cake pans?
    – Do you think it is definitely necessary to have a solid base for the mylar/poly-fil-sandwich or could it be placed on top of foam (my acoustic drum shells are filled with foam cylinders from the bottom up to about 3.5″ from the top). It would be nice to just put the sandwich on top of that without having to mount a solid base inside the shell.
    – Do you have any information regarding the specific weight of the poly-fil you used? I can find “polsterwatte, polstervlies” here in germany but none of the products have a thickness of 1″. Mostly the information given about that material is something like 100g/m2 (up to 500g/m2…).
    – Browsing your site i stumbled upon the 3-zone-concept drawing. Do you think that would (in theory) also work with mylar/poly-fil instead of metal/foam – especially the outer ring part?

    Thank you so much,
    best regards


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