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Difference between AltFalseTrSupport & the "new" algorithm

PostPosted: Sat Mar 11, 2017 6:19 pm
by anttipi
Is false triggering suppression effectiveness the only difference between AltFalseTrSupport vs. the new algorithm or are there some other drawbacks to using the older version? In other words, if false triggering is not an issue (and easily manageable with DynLevel/DynTime etc.), is it "equally OK" to use either of the suppression algorithms?

I've been setting up my new ARM-based MD from scratch and for the life of me, it's impossible to get consistent triggering on my Yamaha PCY135 rubber hihat pad unless I enable AltFalseTrSupport. At least 1/4 of hits played in a semi-quick succession (e.g. normal disco beat) are not registered in Megadrum Manager if the newer algorithm is used - no matter how the Thresholds are set and even with DynTime/DynLevel at 0 and Retrigger at 1. With AltFalseTrSupport enabled however, it's easy to get the hits to register properly.

(I must have had AltFalseTrSupport enabled on my old Atmega because I can't remember witnessing any such problems previously.)

Re: Difference between AltFalseTrSupport & the "new" algorit

PostPosted: Sun Mar 12, 2017 8:27 pm
by dmitri
The standard false triggering suppression algorithm should work better. But you can use either standard or alternative - there is no difference for any other functionality.

Re: Difference between AltFalseTrSupport & the "new" algorit

PostPosted: Sun Mar 12, 2017 11:06 pm
by anttipi
Dmitri, I know you recommend using DynTime and DynLevel first before resorting to raising Retrigger. I followed that route but with the newer (default) algorithm, I had to raise DynTime/DynLevel so high that it effectively ruined quick successive hits.

Finally I tried raising Retrigger from 1 to 2 and saw that this enabled me to drop DynTime and DynLevel both to zero (!). Surprisingly, this seemed a little better for getting successive hits and I got no false triggering.

Any thoughts? Seems weird to me that just raising Retrigger by 1 gave me better response than fine tuning DynLevel and DynTime.

Re: Difference between AltFalseTrSupport & the "new" algorit

PostPosted: Sun Mar 12, 2017 11:16 pm
by dmitri
This is indeed quite strange since 1ms and 2ms should make very little difference.

Re: Difference between AltFalseTrSupport & the "new" algorit

PostPosted: Mon Mar 13, 2017 7:06 am
by anttipi
All I can think of is the extra 1 ms is just enough to suppress post-hit vibrations - i.e. the same thing DynLevel/DynTime would achieve on a finer level.

I was just surprised I get more satisfactory triggering results for quick successive hits by simply upping Retrigger and ignoring DynTime/DynLevel altogether (set to zero).

My hihat pad is in an input with a rectifier (PS set to disabled) - should the PS board have any effect on triggering sensitivity, false hit suppression and bow/edge separation? I have read the rectifier cools down the signal a bit but I guess that per se shouldn't matter.

Bow/edge separation at the moment is satisfactory but not perfect (hard hits on bow sometimes trigger edge), so maybe I should try a non-rectified input just in case.

Re: Difference between AltFalseTrSupport & the "new" algorit

PostPosted: Thu Mar 30, 2017 3:43 pm
by anttipi
dmitri wrote:This is indeed quite strange since 1ms and 2ms should make very little difference.


Dmitri, thought you'd like to see a screenshot as, yes, it is strange.

This not only happens on Yamaha rubber cymbals but also on Drum-Tec Diabolo meshpads. Raise Retrigger on both Bow and Rim/Edge from 1 to 2 and voilá: no apparent need to touch DynLevel/DynTime at all (can pretty much be left at zero) and the response/sensitivity seems better than leaving Retrigger at 1 and using DynLevel to get rid of double triggering! This is especially nice for meshpads' rim triggering because DynLevel/DynTime would otherwise be needed to be raised quite high, which kills sensitivity.

I certainly don't mind this behavior as it makes setup super simple. Mind you, much of my set is on individual stands - I'm not sure if DynLevel/DynTime are required to counter crosstalk (that would make the setup a big more complicated, I guess).

The screenshots were taken with Alt Sampling and AltFalseTrSupp disabled. MD is the newest ARM, latest firmware. Nothing was changed except Retrigger for Rim/Edge.

retrigger1.png

retrigger2.png

Re: Difference between AltFalseTrSupport & the "new" algorit

PostPosted: Wed Apr 19, 2017 6:13 pm
by maru_engineering
One question anttipi, did you settle with using the old AltFalseTrSupp or the new one when you describe the Retrigger behavior? I'm trying now to setup my kit and I'm looking for the best possible configuration for the time being. Thank you!

Re: Difference between AltFalseTrSupport & the "new" algorit

PostPosted: Sat May 20, 2017 4:37 pm
by anttipi
maru_engineering wrote:One question anttipi, did you settle with using the old AltFalseTrSupp or the new one when you describe the Retrigger behavior? I'm trying now to setup my kit and I'm looking for the best possible configuration for the time being. Thank you!


Sorry for the delayed answer but eventually after some further A-B testing, I found the NEW algorithm better, in other words, with AltFalseTrSupp DISabled.

This was for two reasons:
1) The newer algorithm is way easier to set up - in most cases I can start with DynTime/DynLevel at zero, which is already close to perfect (mesh pad rims being an exception) and gradually raise a little from there as needed.
2) With false/double triggering sorted out as described above, the newer algorithm provides better sensitivity (tested with snare rolls).