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Electrical Crosstalk on hihat input

PostPosted: Sun Oct 12, 2014 6:51 pm
by DonGui
Hi everyone,

I've been having trouble with crosstalk that I didn't have until I updated MD firmware some time ago. Unfortunately, I'm not sure which firmware version I had before the issue appeared, but I believe it appeared with firmware 20140809. I'm not saying that the issue is firmware-related though, it's just a possibility.

I've been getting a lot of crosstalk specifically when I hit the hi hat. It tends to trigger the kick as well, though sometimes it can be the snare of bass tom. My pads are basically those of a Roland TD-30k, so my hihat is mechanically isolated from the rest of the kit, and so is the kick pad.
I tried a few thing to confirm that the issue is electrical :
When I unplug the kick pad's jack on the pad's side, I still get crosstalk.
However, if I unplug it on MD's end, the crosstalk stops.

Since this pointed toward crosstalk in the cables, I tried to differentiate the path that took the hihat cable from the path that took the rest of the cables, to try and make them less parallel, but it didn't change anything.

I've changed my megadrum's settings to try and mitigate the issue, but I end up pushing Xtalklevel on the kick up to 7 and I still get a few miss triggering of the kick (though way less than before). Also, some of the strokes on the kick fail to trigger now when I play.

I don't know what to think of all this, especially since I didn't use to have such trouble with crosstalk and haven't changed my pads, or my cables or anything.

I'm joining some screenshots of my config for the HH and the kick.

Thanks in advance for the help !

Guillaume

Re: Electrical Crosstalk on hihat input

PostPosted: Sun Oct 12, 2014 9:06 pm
by dmitri
1. If you have a cable connected to MegaDrum without anything connected on the other end, it will serve as a quite sensitive antenna for any electromagnetic interference, including for high voltage signals from other pads/cymbals.
2. I see that you set quite low DynLevel/DynTime on all inputs which may have negative effect on crosstalk.
3. Can you definitely determine which firmware the problem started with, if it was at all caused by firmware change?

Re: Electrical Crosstalk on hihat input

PostPosted: Tue Oct 14, 2014 8:54 pm
by DonGui
Hi Dmitri,

I dug out old firmware versions I still had, re-installed the 20140629 one, from a time I didn't have issue with crosstalk, re loaded the old config files and I still got crosstalk issues, so now I know it's not firmware related.

I realised that I hadn't tried something obvious, which is changing the hihat's cable, and I think using a new one leads to a bit less crosstalk but it's hard to be sure as the issue is not constant.

I went back to fiddling with the pad settings and specifically Dyntime and Dynlevel as you said. I only did so on the kick, thinking that only it needed fixing since the hihat wasn't miss triggering when i used the kick, but should I try raising the parameters on the hh as well ? Anyhow I think raising it on the kick had a positive impact, but I still get occasional miss triggering on the kick when i hit the hh.

I'm posting screenshots of the new config below. Do you think of anything else which I could try ?

Thanks for your help !
Guillaume

Re: Electrical Crosstalk on hihat input

PostPosted: Wed Oct 15, 2014 10:38 am
by dmitri
Please, post MIDI Log screenshot showing Kick triggering when you hit HiHat.

Re: Electrical Crosstalk on hihat input

PostPosted: Wed Oct 15, 2014 1:09 pm
by angr77
Dmitri - just a quick note...DonGui has enabled "All gains low" in the 20141011 FW...which currently will do some "future tricks" :-)...is this valid also for the STM32F103RCT6?? (Logically - people should leave the "All gains low" unchecked for the moment if using ARM.

ANGR77

Re: Electrical Crosstalk on hihat input

PostPosted: Wed Oct 15, 2014 2:26 pm
by dmitri
angr77 wrote:Dmitri - just a quick note...DonGui has enabled "All gains low" in the 20141011 FW...which currently will do some "future tricks" :-)...is this valid also for the STM32F103RCT6?? (Logically - people should leave the "All gains low" unchecked for the moment if using ARM.

No, these "future tricks" are only possible on new SM32F205RCT6. On STM32F103RCT6 "All gains low" is ignored.

Re: Electrical Crosstalk on hihat input

PostPosted: Fri Oct 17, 2014 5:35 pm
by DonGui
Hi Dmitri

Here's a screenshot showing the midi miss triggering on the kick (note 36). I was only hitting the hi hat. This has been made with the same settings as in my last post, and it's weird but today I'm getting more crosstalk than I did at the time I took the screenshot.

Guillaume

Re: Electrical Crosstalk on hihat input

PostPosted: Fri Oct 17, 2014 8:03 pm
by dmitri
Please post 'Raw MIDI' screenshots showing output when you:

1. hit Kick light
2. hit Kick hard
3. hit HiHat bow light
4. hit HiHat bow hard
5. hit HiHat bow and you have a crosstalk to Kick

Re: Electrical Crosstalk on hihat input

PostPosted: Fri Oct 17, 2014 8:08 pm
by dmitri
Also, can you try this:

1. connect your kick to another input, say Aux10.
2. copy Kick input settings to Aux10 Head settings.
3. disable Kick input by setting its Note to 0.
4. disable Aux10 Rim input by setting its Note to 0.

Do you still get the same crosstalk?

Re: Electrical Crosstalk on hihat input

PostPosted: Sat Oct 25, 2014 6:09 pm
by DonGui
Hi Dmitri,

Sorry for the delay. I went ahead and tried switching physical input for the kick, and the crosstalk was dramatically reduced. I could lower the Xtalk Level on the new kick input to 2 while still getting no miss triggering of the kick when playing the hihat.

So I've got a workaround to the problem, but is there any way I could tackle the issue and be able to use the usual kick input ? Is my hihat output just too hot, and if so is there a way to cool it down to put an end to crosstalk ? Am I the only one with such issues with VH-11 ?
Do you want me to do the tests you asked in your former post and post the screenshots, would that help diagnose further ?

Thanks for your help,
Guillaume