DIY: finally, 3-ply+hotspotless+positional sensing

[stringerbell]

I have some new (and promising) result! However my design choice is again changing (while still trying to achieve the same goal).

I've reached out to Mike from Drone Triggers because I initially had some questions about his LV hihat conversion I saw on youtube. I also saw his halo trigger in action ( https://www.youtube.com/watch?v=2OvPPA8St0o ) and it's based on a side trigger design.

His reasons for a design based on less triggers are very similar: the foam used on triggers is a very critical piece, and high quality foam with the right characteristics is expensive. When using high quality foam with a low compression set value (hint: Poron by Rogers corp) you can get amazing results with a single side trigger.

He's basically shared all the details about how the halo trigger system is designed and I'm making a DIY replication of it, and even with bad foam the results are already very promising. I'm getting fairly good response all accross my 3ply head (14") and positional sensing in Ring mode also works somewhat already. There is still a dropoff when I go further away from the piezo but the expectation is that this will see a big improvement when my Poron foam arrives (next monday), currently I still use some cheap sofa foam that I found.

The way the single head piezo is mounted is also very different in order to get much more sensitivity. It's based on how a piezo is mounted in a piezo buzzer box: the piezo is sitting brass side up on a ring (so the ceramic side is suspended in the air, as well as most of the brass, only 1mm of the outer brass is sitting on the ring. Then on top of that is another slightly bigger ring to keep the piezo in place (but it's effectively sitting loose but barely has space to move sideways). and then there is a foam cylinder on the brass side that is the same side as the ceramic (20mm) that makes contact with the head. This cylinder will be replaced one from Poron foam. And then there are a few foam cones around the center of the drum to dampen the big vibrations from center hits a little bit to get an even response. It's amazing how much sensitivity this mounting gives, I went from grain 10 center piezo to gain 2 side piezo in the eDRUMin for the same velocity results.

(If it's not fully clear I can provide a drawing of pictures later).

So while I appreciate this designs from nemo I'm choosing to go a different route. Perhaps I should make a new thread about the build details when it's finished.

[nemo]

Hi, thanks for the update. The snare from the link looks really great! I hope it works also with 3 ply.
I am not sure if it makes sense to diy when the ready product is ready for sale?
Also I'm not sure if it's ok to post some reverse engineered stuff invented by somebody else. Although I am very curious
Do you have any link to the product?

[stringerbell]

Yeah I'm already testing it with 3ply and the results are already better than my PD-120. And I like the DIY part, but also the drone trigger halo system is about EUR 100,-, and I want to convert an entire kit.

He's kind of hard to find and produces low volume, but you can reach out to him on ebay: https://www.ebay.co.uk/usr/kittoys-2012

Now that i'm getting a free sample or Poron foam from rogers corp I can convert my drums for about $10 per drum (excl the mesh head)

btw, That optical hihat controller on his ebay is also awesome, I've been using it for a while and it's much nicer than a VH11 in my experience.

[mrantarctica]

I can vouch for Drone Triggers as well. I had some of the old radial type centre cone design that he used to make. Very high quality, and it worked pretty well. However, still had the issues with hotspot and PS didn't work that well with 3ply Mesh Heads, but none of those are to do with his designs. I think he had some issue with health and so isn't producing a whole bunch any more either, but he has a lot of info from extensive testing and is a good source of what to do and what not to do if you are coming up with a new design. I would say the limitations are availability and also the cost is pretty expensive (IIRC EUR100 + shipping as well for a single drum, it all ads up)

Isolating the ceramic from the brass on the piezo as Drone does will produce the most unadulterated signal but it sounds like it requires a lot of machining to create the conditions where the ceramic moves but the brass doesn't (or vice versa).

I'm still intrigued by AKA Wayne's design using a 3+1 piezo design, with reverse polarity on the centre piezo (my guess is that reversing the polarity increases the separation between centre and edge if all the other cones are close to the edge and improves PS). He described near perfect performance with his design, so I'm trying to replicate that first. I'm working through my build at the moment but still waiting on some parts to arrive before I can give it a go. I plan to try with Roland MH2 heads first, but I may have a Sparedrum 3ply lying around and will try that as well for comparison.

[stringerbell]

So the Poron foam came in and it's a huge improvent over the sofa foam that I used before it, way less dropoff in response on the head when you get further away from the side trigger, to the point where it's negligible. I'm just experiment with different forms of foam dampening for the center to make it less hot compared to the outer parts (as the center has bigger vibrations).

Also, PS works surprisingly well with a sensitive side trigger + poron foam (with the edrumin set to center trigger and PS in ring mode). Currently I added a 8" (or so) foam pad under the center section of the mesh head. It makes the center less hot, while also making the meshhead less "springy" (which I like). For PS it also has an interesting effect, it basically divides the head into 2 zones, where hits on top the foam center circle become "regular hits" and the outer ring next to the foam become "side hits" quite consistently. only the super soft center hits <10 velocity now sometimes register as side hits, but i'll do some more experimenting with adjusting the foam height/type/size.

IMG_1501.jpg (60.69 KiB) Viewed 32 times

but overall i'm super happy with the result.

piezo mount:
(note that the cermamic part is facing down and is freely sitting suspended on a ledge, without much room to move)

IMG_1497.jpg (122.72 KiB) Viewed 32 times

IMG_1498.jpg (136.07 KiB) Viewed 32 times

[stringerbell]

also: I'm getting the impression that adjusting the gain of the rim trigger separately from the head trigger in eDRUMin influences the PS result in ring mode. Can anyone confirm this?
Also, is it possible to see the PS CC value for a hit in the eDRUMin UI? I have been using it in "note" mode until now but when I get Superior Drummer 3 I want to try CC mode. (I don't think that Steven Slate Drums 5 that I use now supports CC based snare articulations)

[mrantarctica]

So the Poron foam came in and it's a huge improvent over the sofa foam that I used before it, way less dropoff in response on the head when you get further away from the side trigger, to the point where it's negligible. I'm just experiment with different forms of foam dampening for the center to make it less hot compared to the outer parts (as the center has bigger vibrations).

Also, PS works surprisingly well with a sensitive side trigger + poron foam (with the edrumin set to center trigger and PS in ring mode). Currently I added a 8" (or so) foam pad under the center section of the mesh head. It makes the center less hot, while also making the meshhead less "springy" (which I like). For PS it also has an interesting effect, it basically divides the head into 2 zones, where hits on top the foam center circle become "regular hits" and the outer ring next to the foam become "side hits" quite consistently. only the super soft center hits <10 velocity now sometimes register as side hits, but i'll do some more experimenting with adjusting the foam height/type/size.

IMG_1501.jpg

but overall i'm super happy with the result.

piezo mount:
(note that the cermamic part is facing down and is freely sitting suspended on a ledge, without much room to move)
IMG_1497.jpgIMG_1498.jpg

Using a firmer piece of foam will transmit your strikes more reliably - that's why there's less drop off. This is because soft foam will absorb a greater amount of energy from your strike before transferring energy to the piezo - whatever isn't absorbed will be transmitted to the piezo to generate the signal. To produce very faithful reproduction of strike velocity you could, for example, use a cone made out of wood. The problem there being that the piezo will break after a few seconds of playing!

Similarly using that design where the ceramic and brass are free to flex more will result in more faithful reproduction of signal. Easy way to test this is to look at how the piezo vibrates if you pass a current through it, then install into the trigger system you are using and pass a current. If it vibrates differently, then clearly the trigger system is altering the interaction between electrical and mechanical energy.

The piezo of centre foam thing is interesting. My guess is that if you strike a head piezo, PS looks at the head signal to be able to decide centre or off-centre. The greater the separation between these 2, the more likely you will get PS to work. My guess is that if you have too much separation, then there'll be a very sharp zone where different notes are played rather than a smooth transition. My guess is that this is why reversing polarity on the centre trigger compared to side triggers produced very good PS for AKA Wayne. That's just speculation though, I'd need to know more about how PS works on edrumin.

[mrantarctica]

I'm just experiment with different forms of foam dampening for the center to make it less hot compared to the outer parts (as the center has bigger vibrations).

This comment is quite interesting, and suggests that you still have a problem with hotspot in the middle of the snare?

Adding foam will alter how much it can vibrate and hopefully the middle will vibrate similarly to the areas just above where your triggers are, and eliminate the hotspot?

[mrantarctica]

The other thing one could try if they couldn't fabricate that piezo holder is to drill a hole at the bottom of the foam cone/cylinder with the diameter of the ceramic (maybe very slightly larger) so the ceramic isn't pinned down by the foam.