Experimental "quiet" e-cymbal

Oct 2012

I have recently converted an second hand acoustic drum kit to an electronic kit by replacing the standard heads with mesh heads and internal triggers. It was done mostly out of interest to see what could be achieved and to give me something to work on. As part of the conversion I built my own electronic trigger to midi converter that I use with FL Studio and various VST drum plugins. The main goal was a kit I could play without annoying neighbours or waking my kids at night. In general the results using the mesh heads are very acceptable for my skill level.

Unfortunately none of the options I could find for e-cymbals met my requirements for quietness.  I could always hear the tak,tak,tak sound of the sticks hitting the cymbal over the music even when wearing good quality sound isolation headphones.  Eventually I decided to experiment and see what I could come up with.  After thinking about many possible options I decided to try an idea I had using mesh since it works so well on the drums and I didn't need any special materials or tools.

The Finished Product
For an early proof of concept I am very happy with the results.  It demonstrates the design idea works and forms the basis for building in other ideas and improvements for those interested in taking the idea further (see later for some of my thoughts).

I haven't seen anyone else do this so I've called it a Hoffmann Mesh Cymbal.  Below is an example of it mounted as a Hi Hat.  (The idea of the blue LEDs came from the Zildjian Gen16 cymbals - just for show)

 

 Another photo at a different angle with the room lights down.

 

And one of the cymbal mounted as a crash or ride.  It looks like it is tilted way down in the photo but that's just from the angle of the camera being above the cymbal.  ;o)

 

Results
Below is a brief video demonstrating the stick noise from the Hoffmann Mesh Cymbal, a PVC Practice Cymbal and a standard (cheap) Hi-Hat Cymbal.  In all cases there is no bottom cymbal which is replaced by a 6inch round foam pad to help dampen the sound.  Remember I am using them as e-cymbals so the actual cymbal sound comes from the drum synth software which isn't heard in these tests.

It can be clearly heard that hitting the edge (the wooden frame) is quite load so I should have put some soft rubber tubing around the edge before covering with mesh. :o(  Hitting the bow is very quiet though and actually seems loader in the video.  You wouldn't hear it at all in another room even with the door open, so I think the prototype demonstrates potential for anyone whose major requirement is quiet practicing or not having to turn up their music to drown out the stick noise on the cymbal.

Construction
The concept...  If you can read the diagram below it shows a cross section of the design.  Probably just easier to move on to the steps and photos below.

Step 1: Decide what size e-cymbal you want to make and cut out a 3 spoke wheel for the cymbal frame from a sheet of 9mm MDF as shown below. I made a 350mm (14inch) diameter cymbal and the width of the frame rim and spokes approx 25mm.  It's a bit hard to see in the photo but I also used a router to put a 45degree bevel all around the outside of the frame wheel.  The bevel will end up on the underside of the cymbal and is purely there to make it look a little thinner when completed - this could easily be omitted.

The outer diameter of the center hub should be appoximately the size of the cymbal bell.  For my design this was 100mm and again the width of the ring is 25mm making the inner hole 50mm diameter as below.  Note this inner hole needs to be largish as the cymbal stand goes through here and if too small will prevent the cymbal from swinging when hit.  The 3 holes need to be slightly smaller than some bolts you have so that they can be screwed in to the MDF like a thread.  (See the photos for the later steps where this is done)  I would suggest experimenting with hole size in a scrap piece of MDF until you find a size that allows you to screw the bolt in firmly.  If you are using countersumk bolts then countersink the MDF holes at this stage.

 

Step 2: You also need to make a bell riser.  This is simply a circle of MDF with the same diameter as the hub of the main cymbal frame above.  Drill a hole in the center of the bell riser disk the same size as a standard cymbal.  Also make three partially drilled holes (approx 1-2mm deep) in the same locations as the three holes drilled in the main cymbal frame - you can use the cymbal frame as a template to mark the positions.  The size of the holes should be slightly larger than the bolts you will be using.  These holes are to ensure the bell riser remains in place on the bolts.

 

 

Step 3:  Now that you have the parts made it's time to start the construction.  First step is to cover the cymbal in mesh.  I used the heavy duty "pet mesh" from the local hardware store.  To cover the cymbal first cut a circle of the mesh about 25-30mm larger than the wood frame you have made.  Then using a staple gun fold the mesh over the frame and staple.  Move from one side of the wheel to the other pulling the mesh snug as you go until you have staples running all the way around.

 

Here is a picture of the frame covered in mesh with staples running all the way around.  As my drum kit is in the corner of the room the underside won't be seen.  I do plan to look at ways of making this a bit neater in future but this is simply a proof of concept to see how everything works so I'm not particularly fussed at how this one looks.

 

 

And here is a picture of the top of the cymbal at this stage of construction.

 

Step 4:  Now it is time to some shape to the cymbal.  Slide the bell riser between the frame and mesh as shown below.  While doing this align the three resesses with the holes in the cymbal frame.

Screw in the bolts you have selected into the cymbal frame.  If you have made the holes the right size the bolts will create their own thread in the MDF as you drive them in and won't require any excessive force.  Screw all three bolts in evenly, doing each one a few turns at a time.

 

As the bolts come through the frame make sure the bell riser is positioned so the bolts are seated in the 1-2mm deep guide holes that were drilled in the bell riser - this ensures everything stays aligned and in place.  Below is an image of the bolts partially screwed in pushing the bell riser against the mesh and creating "somewhat" of a cymbal shape to the mesh.  

 

 

Below is a photo of the top side with the bolts about half way screwed up.  It's actually pretty hard to see the shape it creates in the photo with the black mesh.  In the end the riser lifted the mesh between 25-30mm in my prototype.  I also noticed the mesh seemed to stretch a little over the first few days but settled down after that so don't cut the bolts to length too soon.  Alos if you don't want to loosen everything to remove and cut the bolts then drill a second set of holes next to the bolts to screw in some temporary bolts to hold everything in tension while you remove the others to cut them.

 

 

Step 5: Put some super glue on the mesh/MDF around the hole in the bell riser.  This is to hold the mesh in place when you cut the hole in it to mount the cymbal.  I actually don't think this is necessary but did it anyway.

 

Step 6: Add the electronic triggers (piezos).  I positioned it between the mesh and one of the spokes between a couple of pieces of foam.  Seems to work quite well, the position and tension of the mesh both effect the pickup so a little experimentation is probably required.  I only made this test a single zone pickup.

 

Step 7: Do any tweaking necessary and start using it. 

 

Other things to try

After completing the build and tests there are a number of things that have come to mind that would be worth trying... I don't know if or when I will get to them, for now I have other things to do so if anyone makes their own versions or customisations be sure to let everyone know how they went.  Some thoughts:

 

• Try aluminium screen mesh - not sure if this is a good idea or not.  It may tension better, however aluminium is very susceptable to cyclic fatigue failure so repeated hitting may break through?
• Rubber tubing around the edge of the cymbal frame before adding the mesh.  As can be heard in the test video hitting the wooden frame is quite load, and I am guessing some soft rubber tube around the edge would silence this alot.
• Paint the wooden frame black before construction.  Actually I don't mind the way you can see the frame through the mesh, this is clearly quite different to a standard cymbal so why hide it!
• Use multiple layers of mesh to make it less transparent and also may tension up better.
• Try different size cymbals.
• Add multizone trigger pickups.
• Come up with some ideas to tidy up the bottom of the cymbal where the mesh is stapled down.