Quick thoughts on number of Piezos in 14" pad

[Burtmeister]

Hey guys, I'm now converting a 14" acoustic snare to a trigger using some of the "cake pan" ideas over at Vdrums.com. I will be using a reflection plate instead of the foam cone method. I will be using a 12" mylar drumhead for the reflection plate with 27mm piezos. My question is do you think there would any advantage to using 3 piezos, wired in parallel and spread in a triangular pattern, instead of a single piezo centrally located  on the head?

[Tanimal]

I'm fairly new to this, but I don't think that would work too well.  If wiring them in parallel actually did work and each of them sent a signal separately on the same connection, You might get some double triggering issues with 3 triggers sending signals at the same time through the same line.  Also, why are you using a mylar head?  The idea of the reflection plate is that it imitates having a really big piezo. All of the vibrations, even from the edge, should be transferred to the center.  Unless you are going to tension the head, I doubt the vibrations would transfer very well.  You need to use something rigid that transfers vibration well, like metal. 

[Hellfire]

Hey guys, I'm now converting a 14" acoustic snare to a trigger using some of the "cake pan" ideas over at Vdrums.com. I will be using a reflection plate instead of the foam cone method. I will be using a 12" mylar drumhead for the reflection plate with 27mm piezos. My question is do you think there would any advantage to using 3 piezos, wired in parallel and spread in a triangular pattern, instead of a single piezo centrally located  on the head?

Some people using multiple piezo elements. It can even out triggering. Be sure to place the 3 piezos equidistant from each other in order to get even triggering.

The only draw back would be if you decide to go to a Roland module with positional sensing, it would not properly track the stick hit. But, you don't care about PS (positional sensing), then you have nothing to worry about.

[Burtmeister]

I'm fairly new to this, but I don't think that would work too well.  If wiring them in parallel actually did work and each of them sent a signal separately on the same connection, You might get some double triggering issues with 3 triggers sending signals at the same time through the same line.  Also, why are you using a mylar head?  The idea of the reflection plate is that it imitates having a really big piezo. All of the vibrations, even from the edge, should be transferred to the center.  Unless you are going to tension the head, I doubt the vibrations would transfer very well.  You need to use something rigid that transfers vibration well, like metal.

Thanks for the replies. I was basing the drumhead reflection plate on this project: http://www.hellfiredrums.com/archives/468  I'm not sure if metal would be better or not but Hellfire seemed to have good success with this design. And since I have a drumhead available right now I will try that. Also I'm not too worried about the piezos double triggering. I know people have set up piezos in parallel, I just didn't know if there was any real benefit. Again, I have the piezos available so guess I will try it. I know that with the single piezo on my 10" head I get variance in triggering across the head. I've tried adjusting sensitivity and threshold settings, but I can't get a good balance. I'm hoping having piezos spread out more along the surface I will get more even triggering across the head.

Some people using multiple piezo elements. It can even out triggering. Be sure to place the 3 piezos equidistant from each other in order to get even triggering.

The only draw back would be if you decide to go to a Roland module with positional sensing, it would not properly track the stick hit. But, you don't care about PS (positional sensing), then you have nothing to worry about.

Thanks Hellfire. I don't plan on going the Roland route, unless I win the lottery at some point.    In your drum trigger adventures, have you ever noticed which type of reflection plate worked better? Meaning the X4L mylar reflection plate or a "standard" metal reflection plate like those used by Alesis? This is my first foray into making my own trigger pad and I'd like to get it right the first time through. 

[Tanimal]

Wow, that just seems weird to me.  But hellfire definitely knows what he's talking about and I only know this stuff from theory, not experience, so you can pretty much disregard my post.

[Hellfire]

I'm fairly new to this, but I don't think that would work too well.  If wiring them in parallel actually did work and each of them sent a signal separately on the same connection, You might get some double triggering issues with 3 triggers sending signals at the same time through the same line.  Also, why are you using a mylar head?  The idea of the reflection plate is that it imitates having a really big piezo. All of the vibrations, even from the edge, should be transferred to the center.  Unless you are going to tension the head, I doubt the vibrations would transfer very well.  You need to use something rigid that transfers vibration well, like metal.

Thanks for the replies. I was basing the drumhead reflection plate on this project: http://www.hellfiredrums.com/archives/468  I'm not sure if metal would be better or not but Hellfire seemed to have good success with this design. And since I have a drumhead available right now I will try that. Also I'm not too worried about the piezos double triggering. I know people have set up piezos in parallel, I just didn't know if there was any real benefit. Again, I have the piezos available so guess I will try it. I know that with the single piezo on my 10" head I get variance in triggering across the head. I've tried adjusting sensitivity and threshold settings, but I can't get a good balance. I'm hoping having piezos spread out more along the surface I will get more even triggering across the head.

Some people using multiple piezo elements. It can even out triggering. Be sure to place the 3 piezos equidistant from each other in order to get even triggering.

The only draw back would be if you decide to go to a Roland module with positional sensing, it would not properly track the stick hit. But, you don't care about PS (positional sensing), then you have nothing to worry about.

Thanks Hellfire. I don't plan on going the Roland route, unless I win the lottery at some point.    In your drum trigger adventures, have you ever noticed which type of reflection plate worked better? Meaning the X4L mylar reflection plate or a "standard" metal reflection plate like those used by Alesis? This is my first foray into making my own trigger pad and I'd like to get it right the first time through. 

If you are going to go with the mylar reflection plate, I would only use one piezo. The multiple peizo method works best on a stiff reflector (metal, hardboard, plexiglass). You could get double triggering if you put multiple peizo elements on a flexible reflector like mylar and that is because of how the mylar will deform when hit. I hope that helps.

[Burtmeister]

I'm fairly new to this, but I don't think that would work too well.  If wiring them in parallel actually did work and each of them sent a signal separately on the same connection, You might get some double triggering issues with 3 triggers sending signals at the same time through the same line.  Also, why are you using a mylar head?  The idea of the reflection plate is that it imitates having a really big piezo. All of the vibrations, even from the edge, should be transferred to the center.  Unless you are going to tension the head, I doubt the vibrations would transfer very well.  You need to use something rigid that transfers vibration well, like metal.

Thanks for the replies. I was basing the drumhead reflection plate on this project: http://www.hellfiredrums.com/archives/468  I'm not sure if metal would be better or not but Hellfire seemed to have good success with this design. And since I have a drumhead available right now I will try that. Also I'm not too worried about the piezos double triggering. I know people have set up piezos in parallel, I just didn't know if there was any real benefit. Again, I have the piezos available so guess I will try it. I know that with the single piezo on my 10" head I get variance in triggering across the head. I've tried adjusting sensitivity and threshold settings, but I can't get a good balance. I'm hoping having piezos spread out more along the surface I will get more even triggering across the head.

Some people using multiple piezo elements. It can even out triggering. Be sure to place the 3 piezos equidistant from each other in order to get even triggering.

The only draw back would be if you decide to go to a Roland module with positional sensing, it would not properly track the stick hit. But, you don't care about PS (positional sensing), then you have nothing to worry about.

Thanks Hellfire. I don't plan on going the Roland route, unless I win the lottery at some point.    In your drum trigger adventures, have you ever noticed which type of reflection plate worked better? Meaning the X4L mylar reflection plate or a "standard" metal reflection plate like those used by Alesis? This is my first foray into making my own trigger pad and I'd like to get it right the first time through. 

If you are going to go with the mylar reflection plate, I would only use one piezo. The multiple peizo method works best on a stiff reflector (metal, hardboard, plexiglass). You could get double triggering if you put multiple peizo elements on a flexible reflector like mylar and that is because of how the mylar will deform when hit. I hope that helps.

That actually helps a lot. I guess I'll pass on the mylar idea then. I have an old computer case that I can scalp for a flat piece of metal big enough for my cake pan. Just waiting on a 14" mesh head and I'll throw it all together. Thanks for the help.

[Burtmeister]

Arghh! What a frustrating day! Ok so I took an old computer case and I cut a 12" circle out of the side to use as my reflection plate. I estimate it to be 2mm thick. I used old CDs for my sub resonators. I put 3 on the reflection plate space out equally. Everything else I set up exactly like the Alesis pads. Nada! I had to turn the sensitivity up to 99 to get any reading at all. So I figured it was the three piezo setup. So I took it all apart and put just the single piezo in. Same thing, had to set sensitivity all the way up to get anything. Even tapping the reflection plate had little affect unless I tapped directly over the piezo.  So then I did away with the sub resonator altogether, and mounted the piezo directly to the reflection plate. Same result. So then I'm thinking I've got the wrong piezos. Nope, switched one in my alesis pad and that pad worked fine. I'm using 1" high density foam on top. Anyone have any idea what I'm doing wrong? Could it be the metal of my reflection plate?

[Hellfire]

Arghh! What a frustrating day! Ok so I took an old computer case and I cut a 12" circle out of the side to use as my reflection plate. I estimate it to be 2mm thick. I used old CDs for my sub resonators. I put 3 on the reflection plate space out equally. Everything else I set up exactly like the Alesis pads. Nada! I had to turn the sensitivity up to 99 to get any reading at all. So I figured it was the three piezo setup. So I took it all apart and put just the single piezo in. Same thing, had to set sensitivity all the way up to get anything. Even tapping the reflection plate had little affect unless I tapped directly over the piezo.  So then I did away with the sub resonator altogether, and mounted the piezo directly to the reflection plate. Same result. So then I'm thinking I've got the wrong piezos. Nope, switched one in my alesis pad and that pad worked fine. I'm using 1" high density foam on top. Anyone have any idea what I'm doing wrong? Could it be the metal of my reflection plate?

It would help to see a picture but, I will try anyway. First off, using a sub resonator with one piezo is used to even out triggering. So is using a 3 piezo configuration on a single plate set up. Normally you do not want to do both because they both achieve the same thing by themselves.

Are you sure you didn't damage the piezo elements in any way? What kind of tape are you using to affix the piezo to the plate? You should not be using foam tape. That will not work. You need a film tape or you can epoxy it to the plate.

Don't try taping over the whole piezo as this is no good either. The piezo brass must be firmly mounted to the plate.

Are you sure you soldered your wires to the correct tabs on the jack (don't get mad at this statement, because I have made this mistake myself, that is the only reason I ask.)?

Many people try to do this without soldering at all. Do not try this as it will not work (or if it does, not for long). I'm sorry if some of this seem obvious but I really don't have enough info to help.

[Burtmeister]

Arghh! What a frustrating day! Ok so I took an old computer case and I cut a 12" circle out of the side to use as my reflection plate. I estimate it to be 2mm thick. I used old CDs for my sub resonators. I put 3 on the reflection plate space out equally. Everything else I set up exactly like the Alesis pads. Nada! I had to turn the sensitivity up to 99 to get any reading at all. So I figured it was the three piezo setup. So I took it all apart and put just the single piezo in. Same thing, had to set sensitivity all the way up to get anything. Even tapping the reflection plate had little affect unless I tapped directly over the piezo.  So then I did away with the sub resonator altogether, and mounted the piezo directly to the reflection plate. Same result. So then I'm thinking I've got the wrong piezos. Nope, switched one in my alesis pad and that pad worked fine. I'm using 1" high density foam on top. Anyone have any idea what I'm doing wrong? Could it be the metal of my reflection plate?

It would help to see a picture but, I will try anyway. First off, using a sub resonator with one piezo is used to even out triggering. So is using a 3 piezo configuration on a single plate set up. Normally you do not want to do both because they both achieve the same thing by themselves.

Are you sure you didn't damage the piezo elements in any way? What kind of tape are you using to affix the piezo to the plate? You should not be using foam tape. That will not work. You need a film tape or you can epoxy it to the plate.

Don't try taping over the whole piezo as this is no good either. The piezo brass must be firmly mounted to the plate.

Are you sure you soldered your wires to the correct tabs on the jack (don't get mad at this statement, because I have made this mistake myself, that is the only reason I ask.)?

Many people try to do this without soldering at all. Do not try this as it will not work (or if it does, not for long). I'm sorry if some of this seem obvious but I really don't have enough info to help.

Thanks for the reply Hellfire. No offense taken at the obvious. I'm great at overlooking at the obvious. Ok I was not using foam tape, I was using double sided film tape, stuck onto the side that is completely brass. I'm sure the piezo is good because I stuck it in one of my 8" pads and it worked fine. It just doesn't work on my big 12" plate.

So, with a brand new piezo I've tried again, and failed. Here are pics of this take before I soldered the wires. This time I used a single resonator. I made it myself out of aluminum flashing and it's a little bigger than a cd. And I epoxied the piezo to the sub resonator.









Again, this one didn't work either. I can tap the very center of the reflection plate and I get sound, but anything other than dead center I have to crank it up to 99 in sensitivity to hear anything.

[Guinness]

the picture posted is of 1 piezo.  Thought you were doing three?   Which lead me to think you possibly wired it in Series and not Parallel?

[Burtmeister]

the picture posted is of 1 piezo.  Thought you were doing three?   Which lead me to think you possibly wired it in Series and not Parallel?

I originally started with 3, but was having problems as I stated above. That's why I went to one. Trying to keep it simple now, but I must be missing something because it still doesn't work.

[Hellfire]

Do you have a rim piezo? Are you maybe wirring the head and rim piezo backwards (this two is something I have done myself)? That would make it act the way you are talking about. Just a thought.

[Burtmeister]

Do you have a rim piezo? Are you maybe wirring the head and rim piezo backwards (this two is something I have done myself)? That would make it act the way you are talking about. Just a thought.

I had a rim piezo but I disconnected it to make one less possibility of error. I matched my alesis 8" pad to make sure I matched wiring, and then I even changed the wiring around just in case my jack wasn't standard. Then nothing worked so I put it back to the same wiring as the alesis pad. I just can't figure out why this reflection plate isn't working. It seems so simple. Is it possible that I just made the reflection plate too big?

[Guinness]

when you have it hooked up and tap gently directly on the plate, does it register?  Bad piezo?  (I know you've tried several.  could they all be bad?)
 
 

[Burtmeister]

Well guys, first I'd like to say thank you for your time and thoughts on this project. Secondly I'd like to say Whoo Hooo! I got it! It turns out it was my reflector plate. All I did was cut out another 12" circle out of some thin aluminum I have. Then I stuck the same sub resonator and piezo on that and shazam! it works. I don't know why the piece I cut from the computer case doesn't, but it doesn't. I went round and round with that thing trying all kinds things and it just did not work. My brother had the thought that since it was from the computer case that maybe it was some weird alloy that had dampening properties, after all you don't want your computer case vibrating and being all noisy. I don't know if I agree, but hell I don't have any other ideas. Anyways I'm a happy boy now. It works it works it works! 

[Guinness]

actually, that makes some sense.  The case was powder coated right?  I believe that is thicker than just plain paint, and therefore may have some dampening characteristics.   
 
Glad it works.

[Hellfire]

Awesome news! I would have never guessed the plate itself. This just shows how much of a trial and error DIY can be and how different it can be for each person. I glad to hear you got it figured out.