Problem setting MD parameters

[kimouette]

I'm going to release a new firmware today/tomorrow with a general improvement to a false triggering suppression

Tonight after work I'll install and try that new firmware. I really hope it solves the problem!

Second, I understand you're comparing triggering with another module. Can you make a recording of a fast left-right-left-right roll with MegaDrum and another module?

I'm not comparing triggering with another module since MD is all I have. I wish I could do that comparition, but I cant

Third, if you're still not able to find the fine balance, you can send the pad to me (I will send it back of course) and I'll see what is going on.

That is just the nicest idea! I'm very thankfull for that suggestion you made. But before I do that, I'll want to test different suggestion that have been made here and on Vdrums. Also I'll try your new firmware and if it doesn't work, there are still plenty of setting combination and hardware changes I have to try.

If you are getting three different responses with the three pads then I would look there first.

I did and I'll keep looking at this problem. I did notice one of my tom's second layer of screen was a little "wrinkled". I'll take it off and make sure both layers are "smooth".
I was thinking maybe the variations were caused by the different sizes of the toms/snare.
And if we really want to go into details, we could also say that, since I'm not a robot, there's no way I can hit the EXACT SAME SPOT, at the EXACT SAME DISTANCE from the piezo, at the EXACT SAME STRENGTH.

What are you using for the cone (or whatever you have). Is it a diy pickup or something you bought. Can you post up a picture of one of your pads?

DIY cones made from sand blocks.
Here's what it looks like :
http://picasaweb.google.com/lh/sredir?uname=Kim.Tanguay&target=ALBUM&id=5329632410713662897&authkey=Gv1sRgCPbD6NmYiezJZQ&feat=email

Under the piezo I have cut 3 little squares of double side foam tape, and to stick the cones on the piezos I have cut circles of double side (very thin) tape (it's the Tesa tape you can see on the picture) they are the same size as the ceramic.
The cones all stick up at 1/8" above the bearing edge

Are all of the piezos the same on all three pads?

Yes, all of them are the same (27mm)

What I found though was that if I changed the setting PIEZO to SWITCH it then triggered perfectly. My setting for dual zone pad was NO.

I'll also give that a try but since I have 2 piezos per pad I hope eliminating the rim piezo wont be the solution!


Not enough hours in a day, and not enough days without work!

[macca2004]

"I'll also give that a try but since I have 2 piezos per pad I hope eliminating the rim piezo wont be the solution!"

Maybe it wont be the solution, but eliminating the rim and it's settings out of the equation until you get the pad triggering correctly may help..

Kevin

[gastric]

My overall suggestion is to try to kill double/ghost triggering on your triggers themselves and not in the module. Mesh heads are naturally springy and will vibrate after being struck. While the module can possibl counter that with various settings, those settings typically sacrifice overall playability (lost hits in rolls or fast playing, for example).

Try this:

* Using MCT open the MIDI Montor so you can see what is being triggered by MD.
* Strike your trigger hard once.
* What you may see in MCT is a single trigger at 127 velocity, then a variety of subsequent triggers at much lower velocities.
* The same is likely true when striking the trigger at medium and low velocities/strength.

Now for the sake of illustrating how the trigger itself can correct the issue all together.

* Gentley place your hand on the left side of drum head. Now repeat the steps above.
* Do you see the double/ghost triggers diminish?
* If they diminish but do not completely go away press your hand a little harder against the head and repeat.
* Eventually you should see the double/ghost triggers completely disappear.

You could probably replicate that effect by dampening the head inside the shell. Unfortunately I haven't gotten past that general thought yet. I've never used one, but I'd think those $5 Pearl internal mufflers that screw through your shell and press against the head would work. Though you have to screw a hole through your shell which isn't my preference. But they're easily adjustable from what I see. I'm sure there's some DIY methods as well. LIke install another L-bracket and some more foam yourself. Or, what I'll try, just adhere some mort foam pillars on your crossbar so they press firmly against the head. You just need something to press against the head and absorb the after hit vibrations that are causing the double/ghost triggers. Probably something larger than a Pearl muffler.

Let me know what you think.

Slightly related, I've recently discovered my old Pearl kick pedal is causing double-triggering via it slapping against itself when I don't keep my foot firmly on the kick plate. Crazy stuff.

[Rubis]

Would raising the piezo and cone help stop vibrations too? Maybe moving from 1/16 of an inch to 1/8"? Or a different density foam?

[gastric]

Beats me, I'm in the same boat right now.

Note I have DIY 1-ply mesh heads ranging from 8" to 14". The double/ghost triggering increases with the size of the drum head. I also have a 14" Roland 2-ply head on my snare. It also has double/ghost triggering, but much less extreme than on my 1-ply DIY 14" toms. Note when I say double/ghost triggering I'm referring to with the stock/default settings.

With all that said I really think that some sort of full-face dampening would be most ideal. However, if you're going to do that then you might as well consider using a reflection plate design instead of cone-and-crossbar design as the reflection plate design requires that full-face dampening. I have an extra 14" snare with a 1-ply DIY mesh head I may experiment with a reflection plate to see if it's really any better, how it deals with 2-zone triggers, and how well it handles crosstalk. So you might be solving one set of problems by trading them for another. Regardless, for me the reflection plate testing is likely a different project for a different season.

[Rubis]

Try it out and let us know how it works. I haven't finished my module yet, but after finals are over this friday I should get to work on it more. It seems to me that the more contact with the surrounding area, the higher the crosstalk. That was one of the big things about the mesh head/cone combination. Depending on how you build the crossbar, it can have very good isolation, even from the rims. It will be interesting to see how the reflection plate compares.

[r0bbie]

Beats me, I'm in the same boat right now.

Note I have DIY 1-ply mesh heads ranging from 8" to 14". The double/ghost triggering increases with the size of the drum head. I also have a 14" Roland 2-ply head on my snare. It also has double/ghost triggering, but much less extreme than on my 1-ply DIY 14" toms. Note when I say double/ghost triggering I'm referring to with the stock/default settings.

With all that said I really think that some sort of full-face dampening would be most ideal. However, if you're going to do that then you might as well consider using a reflection plate design instead of cone-and-crossbar design as the reflection plate design requires that full-face dampening. I have an extra 14" snare with a 1-ply DIY mesh head I may experiment with a reflection plate to see if it's really any better, how it deals with 2-zone triggers, and how well it handles crosstalk. So you might be solving one set of problems by trading them for another. Regardless, for me the reflection plate testing is likely a different project for a different season.

I’m on the same trail Gastric, after reading this tread http://www.vdrums.com/forum/showthread.php?t=48939
I did experiment with an extra cloth under my 1-ply Tama mesh, see the results below;

The problem of ghost triggering is caused by the long ringing of the 1-ply mesh (bottom trace),
adding the extra cloth cancels the ringing but makes the pad more noisy (top trace).

I thought the same thing as you do, why not use the best of both worlds, so last week
I have put a piece of hardboard inside my shell and put a piece of foam like this on top.

I adjusted the height of the hardboard so that the tips of the foam are about 1mm higher than the edge of the shell,
oscilloscope results look the same but it still is kind of noisy.

Everything has been put together quite flimsy, the hardboard has just been clamped inside the shell, the foam was not glued to the hardboard,
bud I didn’t had the time to improve because I had to go on vacation

Like you said “So you might be solving one set of problems by trading them for another.” a solution like this would most likely cause problems with positional sensing.

When I return In about a week I will continue with this experiment like making it more solid, using 8mm MDF, using smaller pieces of foam and so on.

I will post results soon after that.

Regards,
Rob.

[kimouette]

Hey Gastric long time no "see"!

Well first I want to eliminate the possibility for the rim piezo to cause the ghost triggering. I have assigned a different midi note to my rim and the ghost triggering definately comes from the head. In my case, changing the rim piezo to "switch" or setting the head piezo to dual layer "yes" or "no" doesn't change a thing. In other words, I definately dont have a crosstalk problem!

Complete change of subject...
Dmitri I'd like to know how much the "All gain Low" decreases the gain.

I do have one hot pad (my damn snare of course) but since my other pads are not as hot as my snare, I'd like to know exactly how much I should increase the gain input for my individual pads in order to get a "Gain 0" equivalent.

Also, the new AltFalseTrSupp works! I mean it did allow me to decrease the Retrigger a little, but as for the "dynlevel" I dont see the difference.

If you compare the first MCT printscreen I showed in my first post with the new one I'm adding right now, you'll see that the threshold was set way to high! With this current setting I'm standing at the limit of ghost triggering: decreasing it to 6 instead of 7 will automatically give ghost triggering. Before that new firware was released, the limit for retrigger was 10. Now it's 7! Just for the info, the old setting showing retrigger :5 didn't work AT ALL!

These setting might change completely though since I'll lower my snare cone a little (yes again). I found my tom2 was giving the most realistic response (especially during fast rolls) and looking carefully at the pad I noticed the head cone was not "coming out" into the mesh head as much as my snare's. I thought they were all 1/8" above the bearing edge, but obviously I did something wrong there, or maybe the cone got "crushed" because I play with my snare more oftently?? Anyway I'll start with the cone and then move on to something else.

the module can possibly counter that with various settings, those settings typically sacrifice overall playability (lost hits in rolls or fast playing, for example).

That is my current problem! Lost hits, or false values while trying to do something regular. For exemple I play left-right-left-right, I might get something like 50-48-97-48. That "97" might sound nice in some situation, but since I didn't do it on purpose I want to get rid of it! But that never happends with my tom2!

Gently place your hand on the left side of drum head. Now repeat the steps above.
* Do you see the double/ghost triggers diminish?
* If they diminish but do not completely go away press your hand a little harder against the head and repeat.
* Eventually you should see the double/ghost triggers completely disappear.

Guess what? I do have a Pearl internal muffler on my snare! But just like I imagined it would do, there's no balance. I mean where the muffler stands I get a certain result, but on the opposite side of the surface, I get something else.
I did that little test you suggested and it works, but the results will vary (I mean the ghost triggering will diminish easily) if I play close to the cone.


(Could that futur positional sensing feature eliminate that problem??)


I totally agree with the idea of solving the problem with the triggers themselves instead of adpating the module to these problems! But this is gonna take some time!

Would raising the piezo and cone help stop vibrations too? Maybe moving from 1/16 of an inch to 1/8"? Or a different density foam?

Maybe I'm wrong, but like I said, from what I see it's the complete opposite! The more the top of the cone seems "crushed into the screen" (so the higher it is), the more false/ghost triggering I have.


Gastric I tried to search for "drum reflecting plate" on google, but didn't find anything relevant. Could you send a link where I could see what these are?


...I read on Vdrums that some people can set their threshold and retrigger to 1 without having any ghost/false triggering whatsoever! I'm so jealous! But of course these people probably paid a lot for their perfect pads... which I didn't

[gastric]

You can see some photos of my first e-drum kit (actually first ANY type of drum kit), a 1990's S&S Industry and Pintech kit. The S&S drum triggers used a standard reflection plate design. I couldn't quickly find some definitive guide though I thought Hellfire had one somewhere. Basically you put have a bottom layer of firm supporting foam, some sort of "plate" like a circle of flashing, adhere the piezo to that plate, then put a softer layer of foam on top of the plate that will firmly press against the drum head. Works with mesh or acoustic heads since it provides a full-face dampening.

http://www.vdrums.com/forum/showthread. ... tion+plate

I opted for the crossbar as the parts were more readily available and it's what everyone else was using. And with an acoustic conversion you still have to come up with some way to support the reflection plate against the head, so you're back to some sort of crossbar or using a LOT of foam to fill the entire drum.

I'll message Hellfire and see if he can provide some definitive links to reflection plate design as that's what he uses. And he's probably the most unrespected DIY e-drum designer IMO. The guy has a TON of ideas and provides them all via well written technical documentation on his website here: http://www.hellfiredrums.com/

And you're correct. I'm not sure if the plate design supports positional sensing technology or not. I haven't gotten that far yet.

[Rubis]

I guess that makes sense. Lowering the cone would decrease sensitivity = less false triggering. I was thinking that raising it would help dampen the vibrations, but I guess that make it transfer to much of the vibration to the piezo.

Since most of the trouble seems to be when hitting away from the cone, maybe place a ring of foam around the edge of the head? If it is even and well supported, then that wouldn't mess with positional sensing, would it?