Different thresholds on equal pads (inputs 5,7,9,11)

[Alek_A]

Hi,

I have just done experiment with four Roland PDX-100 pads that are connected to 4/5, 6/7, 8/9, 10/11 inputs. I set equivalent settings to all four pads:

PDX-100-Rim-40.png

The LCD showed no blinking:

Thresholds-40-40-40-40.png

Then I started lowering input's threshold until related indicator on the LCD started to blink. And I did this for all four pads.

Thresholds-14-35-11-14.gif

Strange, that the indicators start to blink at different thresholds. Indicators for 5th, 7th, 9th and 11th inputs start to blink at 14, 35, 11 and 14 threshold levels respectively.
Is it OK? Or should I tweak something before continuing to adjust pads?

Furthermore I'm observing strange correlation between 5th and 7th channels they blink almost the same way. And one more thing. When I set threshold of 5th channel to 15 blinking disappears not only on 5th channel but also on 7th channel!...

[airflamesred]

Its just the nature of things. If inputs are self triggering then raise the threshold. All piezos vary, somewhat, in my experience.

[dmitri]

Output impedance of piezos differ and it may effect the sensitivity of inputs.

[Alek_A]

Its just the nature of things. If inputs are self triggering then raise the threshold. All piezos vary, somewhat, in my experience.

Output impedance of piezos differ and it may effect the sensitivity of inputs.

But swapping pads doesn't change anything. It seems that inputs themselves have different sensitivity. Is it normal? I'm asking because it's too usual in my experience that one unfixed problem leads to another problems. So it's better to be sure!

[dmitri]

Raise Threshold on all these inputs until they all stop triggering without hits and then post settings for inputs 4/5 and 6/7.

[Alek_A]

Dmitri, at (15,35,12,15) thresholds for 5,7,9,11 inputs I see no indication on LCD.
Although the indication on specific channel depends also on other channel's thresholds.

Assuming thresholds for 5,7,9,11 channels are (15,35,12,15), no indication. In the following tests the threshold of one channel is lowered, others left intact.
Let's lower 5th channel's threshold to 14: equal indication appears on 5th and 7th channels - this is the most strong impact. Also rare splashes occur on 9th channel.
Let's lower 7th channel's threshold to 29: indication appears on 7th channel as expected. Let's lower threshold to 20: Rare splashes occur on 11th channel.
Let's lower 9th channel's threshold to 11: indication appears on 9th channel, often strong splashes occur on 11th channel and equal not so strong splashes occur on 5th and 7th channels.
Let's lower 11th channel's threshold to 14: indication appears on 11th channel, rare medium splashes occur on 9th channel and very rare little splashes occur on 7th channel.

Dmitri, if you want, I can give you remote access to my computer, with camera pointed at the MegaDrum's LCD.

[dmitri]

No need for the remote access. Just take the screenshot of settings.

[dmitri]

One more thing - setting the input at the brink of threshold of triggering without hits (picking up noise in fact) causes MegaDrum to unnecessarily sample inputs much more often which cause MUXers to switch inputs with high frequency all the time. This in turn will create additional noise on power rails which in turn will add more noise on all other inputs and may cause triggering on any other inputs with thresholds set close to the noise level creating a vicious circle. To sum up, you shouldn't set Thresholds close to the noise threshold levels.

[Alek_A]

Settings are the same for all four pads except of Threshold on odd channels. Screenshot in the first post.
Thanks for explanation! I suppose this "crosstalk" is normal. I actually don't use these low thresholds. It's a test, I just found it strange and decided to share, but now it's clear!
What about different threshold levels itself?

[dmitri]

Settings are the same for all four pads except of Threshold on odd channels. Screenshot in the first post.

Nevertheless, pleased do the screenshots just as I asked. There were several occasions on the forum that it mattered.