False Trigger Problem / AltFalseTrSupp to Yes new or old?

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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby dmitri » Thu Jun 20, 2013 10:09 pm

The fact that your HighLevel is only 333 even with Gain 8 is very specious. Usually mesh type pads produce very strong signals to the point that they need to be "cooled" down sometimes. It seems to me there is something wrong mechanically with the pad. When you sort out the signal strength, look at viewtopic.php?p=20543#p20543 for the guide on how to get best triggering with mesh type pads.
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby Andrej » Fri Jun 21, 2013 4:19 pm

dmitri wrote:The fact that your HighLevel is only 333 even with Gain 8 is very specious. Usually mesh type pads produce very strong signals to the point that they need to be "cooled" down sometimes. It seems to me there is something wrong mechanically with the pad. When you sort out the signal strength, look at viewtopic.php?p=20543#p20543 for the guide on how to get best triggering with mesh type pads.


Thanks Dmitri,

what do you have in mind when you say something is mechanically wrong with the pad? The construction is very simple, consists of four parts:
(1) Snare drum
(2) Snare stand
(3) Trigger (mounted on the inside wall using the lug screws)
(4) Mesh head (DDT 2-ply)

I assume (1) and (2) should not be an issue. I've tested the trigger outside the pad, and it gives a nice clean spike (slightly hitting it directly with the drum
stick). So could it be the mesh head? It looks fine, although the two layers are not bonding together.

The reason the trigger is not very hot is probably by design, as it is a commercial trigger. It's got a very thin rubber pad (approx. 1mm) between the piezo
and the mesh, and about 2cm of thick foam between the piezo and the mount.

Could someone post a waveform of a nice trigger signal, so I know what to aim for?

Thanks
-Andrej

EDIT: Remounted the trigger elsewhere and so far much better. Now going through the procedure to find optimal settings.
Megadrum32(STM32F103RCT6) with Rectifier board, FW 20130612.
Mapex Fastpack A2E conversion using cakepan+cone method.
Yamaha PCY-135, PCY-155, RHH-135.
(Not yet finished)
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby Andrej » Fri Jun 21, 2013 8:04 pm

Ok, now I followed your steps, after getting a nicer signal, and got the following:

Threshold 14
DynLevel 3
DynTime 52

Before I started:
HighLevel 500
Gain 8
Retrigger Mask 1
MinScan 40

It's pretty good now. To get it even more sensitive, I think I need to increase DynTime.

Your steps don't adjust MinScan and Retrigger Mask. Should they be left like this, or be further optimised? Does this trigger signal look good, or
should I try to get a better signal?

Thanks
Andrej
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Megadrum32(STM32F103RCT6) with Rectifier board, FW 20130612.
Mapex Fastpack A2E conversion using cakepan+cone method.
Yamaha PCY-135, PCY-155, RHH-135.
(Not yet finished)
Andrej
 
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby dmitri » Fri Jun 21, 2013 8:42 pm

Judging by the signal's frequency MinScan 40 is just fine.
The main requirement for the signal is that it subsides monotonously after a hit without spikes higher than the first spike.
Neither DynTime nor DynLevel have any effect on sensitivity, they are for optimizing false triggering suppression/fast rolls triggering.
HighLevel 500 with Gain 8 means the signal is still somewhat weak.
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby Chrescht » Mon Jun 24, 2013 4:24 pm

Hi,

@Dmitri,

I have a 14" steel snare with DDT double ply Mesh with relative high tension and Roland Type centered trigger.
It triggers absolutely fine, only my positional sensing is inconsistent.
I have analysed the waveform and the first halfwave is positive but
a second wave amplitude is higher than the first wave amplitude.
What causes this problem?
Is it more a mechanical or elcetrical(Piezo) related problem?
The waveform has also a lot of spikes.
Will your precision rectifier smoothen the signal?

Thanks
Greetings

Christian
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby dmitri » Mon Jun 24, 2013 7:12 pm

Chrescht wrote:I have a 14" steel snare with DDT double ply Mesh with relative high tension and Roland Type centered trigger.
It triggers absolutely fine, only my positional sensing is inconsistent.
I have analysed the waveform and the first halfwave is positive but
a second wave amplitude is higher than the first wave amplitude.
What causes this problem?
Is it more a mechanical or elcetrical(Piezo) related problem?
The waveform has also a lot of spikes.

It does seem like a mechanical problem. The signal must subside more or less monotonously.

Will your precision rectifier smoothen the signal?

It doesn't smoothen it, it just rectifies it. If it were smoothing it, with a well constructed pad it would have smoothen articulation and probably made fast rolls impossible.
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby Chrescht » Tue Jun 25, 2013 2:19 am

Hi Dmitri,

Thanks for the hint.
I will start with different Mesh tensions.

Greetings

Christian
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby Chrescht » Thu Jun 27, 2013 8:32 pm

Hi all,

Just for info:

lowering the Meshhead tension solved the problem with the second wave higher than the first one.
Now tweaking for the positional sensing...

Greetings

Christian
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Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby Andrej » Sat Jun 29, 2013 10:10 pm

dmitri wrote:The main requirement for the signal is that it subsides monotonously after a hit without spikes higher than the first spike.


Changed to a crossbar design with a cone trigger. Now I get a nice signal. At least this seems to "subside monotonously". And a scan time of 2ms should
work well here too.

But I do have hot spot issues. So now I'm reading up on the solutions that other people have done.
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Megadrum32(STM32F103RCT6) with Rectifier board, FW 20130612.
Mapex Fastpack A2E conversion using cakepan+cone method.
Yamaha PCY-135, PCY-155, RHH-135.
(Not yet finished)
Andrej
 
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Joined: Wed Jul 20, 2011 9:30 am

Re: False Trigger Problem / AltFalseTrSupp to Yes new or old

Postby henk_thl » Sun Feb 05, 2017 3:07 pm

Hi all,

Perhaps someone can help me. I'm using a Roland RT-30k kick trigger. (and I even tried it with a DDrum red kick trigger.)

But when I play my kick, I get a lot of rim hits. They interfere with my double bass work. I'm using a 682 mesh head on a 22" kick. The other heads aren't giving the rim information back.
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