Positional sensing testing

[angr77]

Hi!

1. Only the head trigger can handle PS. The rim is not in volved here. Use the rim as as usual trigger and trigger a sound but with the PS set to disabled.
2. There is fine information available. Go to Dmitris post on the first page...click on the PS-board Post. Follow the thread.
3. MD sends PS info on cc channel 16 for all drums. 0-126 dependent to where you hit on the head. (minscan value will have impact if PS info could be read. I am using 50)
4. Same channel cc16. It does not matter. Looking on the midi data stream...first it sends the PS value followed by the midi note and velocity...so if you have 5 pads with ps enabled...no problem. You will have more problems to find a VST that supports PS on more than snare and ride. (SD and AD).
5. Pass...

Angr77

[dmitri]

As per http://www.megadrum.info/content/pads-settings, description of MidWidth:

Next screen ChXX: PadName->DualMidWidth (only available on Rim/Edge inputs):

<Ch04: SnareR >
DualMidWidth 15

For dual piezo/piezo pads: The width of signals for rim shots. It can be set between 0 and 15. The higher the value the easier to get rim shots and more likely to get false rim shots on head or rim hits and vice versa.
For dual piezo/switch pads this option is disabled.

[alexmcintosh]

Angr77 & Dmitri;
thanks you guys for the replies. Greatly appreciated.

OK, so the Positional Sensing, high and low values are only defined by the Head (/bell) trigger.
(I'm curious as to why the Megadrum has Positional Sensing input for monitoring the Rim/Edge?)

One More question I have is that my Positional Sensing goes a little haywire when I'm hitting/tapping close to my center head. (my build = Drop in Cake-Pan build, with center QuartzTrigger cones, Hart Magnum head) Here's what happens...
1.) Rim hit: PS=0, caret = all the way to the Right of LCD readout.
2.) Start Tapping toward the center of my snare
3.) Observe: PS=1, 2, 3,... 19, caret = start to move toward the left of LCD screen
(Everything is great!, just as hoped)
4.) 1" from the very center of the Cone. PS=5, (caret=corresponding position)
5.) On top of Cone: PS=5.

So, there's a vortex once I start to get very close to the center. This starts directly above my bolts that hold my center cone plataue. The triggering is terrific, and I've set minScan =50 (although I think it triggers better at minScan=40)

Thanks.. Alex M.

[dmitri]

OK, so the Positional Sensing, high and low values are only defined by the Head (/bell) trigger.
(I'm curious as to why the Megadrum has Positional Sensing input for monitoring the Rim/Edge?)

I'm not sure what you mean.

One More question I have is that my Positional Sensing goes a little haywire when I'm hitting/tapping close to my center head. (my build = Drop in Cake-Pan build, with center QuartzTrigger cones, Hart Magnum head) Here's what happens...
1.) Rim hit: PS=0, caret = all the way to the Right of LCD readout.
2.) Start Tapping toward the center of my snare
3.) Observe: PS=1, 2, 3,... 19, caret = start to move toward the left of LCD screen
(Everything is great!, just as hoped)
4.) 1" from the very center of the Cone. PS=5, (caret=corresponding position)
5.) On top of Cone: PS=5.

I can only say that the Positional sensing is very "sensitive" to the quality of a signal(pad quality), tightening and hot spotting, regardless if it is a MegaDrum or a Roland.

[angr77]

For the first question - Alex - Think of it like this, you want to use the two MD inputs for two separate drums and use PS for both...that's why you see PS function on both the head/rim input. The RIM input could be used for something else..requiring PS.

Note: PS on the rim is not offered by any major hardware vendor or in any soft plugins that I have seen...

Angr77

[alexmcintosh]

For a cymbal, wouldn't it be best if the piezo were placed on to the Bell area? (the center of the cymbal) Is it possible for a bow piezo to detect a difference from where the Edge is vs Bell?

[angr77]

Hi Alex.

Yes that's right. I have only experience from e-cymbals from leading vendors...but some of them have the piezo mounted in the center. My Roland CY-15R (Three zone piezo/switch/switch) do officially support positional sensing on the piezo. Also Addictive Drums (and I think I have seen superior drums do this also) support PS on Rides, over cc:16 and it works like a charm. It can select sounds from shaft to tip. You can't trigger the bell sound through PS in AD.

I would also add that using the CY15R as usual (no PS) works more than perfect for me.

Angr77

[alexmcintosh]

One thing I wanted to clarify... Do I need a rectifier if I have the 'Positional Sensing addon board'? Or a voltage limiter?
(Note: using the "Alesis/Positive Wiring Diagram", I once did an oscilloscope test of the output waveform and the leading edge showed the initial waveform to go negative.)
Below I have two drums setup one with the Alesis/Positive Wiring & the other with the Roland wiring [ie. the center Piezo Ceramic Lead goes to ground], both tend to have a hard time with Positional Sensing. The center bounces from 8-19, and many edge hits will bounce up as well)

My Results (for Drop-In CakePan build):
Roland Wiring
(14" Snare Drum, Roland Mesh Head)
Light hits - Center ~= 7-18 (mostly 7)
Light hits - 1/4 out ~= 18
Light hits - 1/2 out ~= 16
Light hits - 3/4 out ~= 0-11 (mostly 8)
Light hits - edge/rim ~= 1-2
Hard hits - Center ~= 0-18 (mostly 8)
Hard hits - 1/4 out ~= 19
Hard hits - 1/2 out ~= 6
Hard hits - 3/4 out ~= 0-17 (mostly 17)
Hard hits - edge/rim ~= 5

Alesis/Positive WiringAlesis/Positive Wiring
(16" tom, Billy Blast 3ply Ballistic Mesh Head)
Light hits - Center ~= 13-19
Light hits - 1/4 out ~= 3-12 (mostly 9)
Light hits - 1/2 out ~= 0-15 (mostly above 10)
Light hits - 3/4 out ~= 0-11 (mostly 0)
Light hits - edge/rim ~= 0-3
Hard hits - Center ~= 6
Hard hits - 1/4 out ~= 17
Hard hits - 1/2 out ~= 0-17 (mostly 17)
Hard hits - 3/4 out ~= 6-17 (mostly 17)
Hard hits - edge/rim ~= 3-6

My Setup:
Threshold = 10
Gain = 0
HighLevel = 575
Retrigger Mask = 0
DynLevel = 8
DynTime = 8
MinScan = 50
PosLevel = 1
Pos Low = 0
Pos High = 19

[angr77]

The PS board is including rectifiers for MD inputs 4, 6, 8, 10, 12.
The PS function is not an exact science...you will see some jumps...but I think after loooking on your figures that the PS trend curve could be improved a bit.
I am using the PSpos level set to 2 for a 35 mm Piezo on hareness. Just to dialin using the MD...for high and low values.
I would increase the minscan sligthly and see if things improves. 60, 70 etc. I have seen examples on 80 without any big losses in performance.


Best regards

Angr77

[dmitri]

If you have a Positional sensing board (precision rectifiers) then piezo wiring on on inputs 4, 6, 8, 10, 12 doesn't matter.
Also did you try to use the recommendation:

With PS enabled and LCD showing one of the PS settings, when hitting the snare you can see in the botom left of the LCD the relative position of the hit as calculated by MegaDrum: ^ symbol shown more to the left for centre hits and more to the right for close to rim hits. You will also see the calculated PS value of the hit for currently selected PS algorithm (1, 2 or 3) which you should use for setting PositionalLow and PositionalHi properly.

from http://www.megadrum.info/content/miscellaneous-settings to help you find right PositionalLow and PositionalHigh ? Your values seem way off, especially PositionalLow - you set it to 0 so you'll never be able to get full PS range.