The 'Gain' parameter

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Re: The 'Gain' parameter

Postby gabriel1712 » Thu Apr 30, 2009 1:23 pm

Did you by chance cap the max with 'Compression'?
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Re: The 'Gain' parameter

Postby gastric » Thu Apr 30, 2009 1:33 pm

No I did not. Compression and Shift = 0.
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Re: The 'Gain' parameter

Postby Ken Forgettable » Thu Apr 30, 2009 9:41 pm

gastric wrote:I'm not sure that physical dampening on a bar-and-cone-and-mesh trigger affects voltage output

I agree with gabriel1712. Different sensor mountings change output levels as well as if not better than using a voltage divider. Not forgetting the trigger is the slave of the drum – not the other way round – I say drum head tension (and dampening) on an e-drum is there to enhance technique only.
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Re: The 'Gain' parameter

Postby dmitri » Sun May 03, 2009 10:13 pm

When you set HighLevelAuto to Yes, MegaDrum set a new HighLevel using the formula:
'New HighLevel' = ('registerd HighLevel' + 'old HighLevel)/2
thus adjusting HighLevel in succession. So even if the last strong hit was registered raw as '1023' (i.e. a maximum level), HighLevel won't be set to this level.

The relation between 'Gain' 0 and 8 is around 1:2. 'Gain' is applied to a raw signal before 'Curve' is applied. So if you apply a logarithmic 'Curve' the difference between low and high gain levels will be noticeable for soft hits and almost none-existent for strong hits. Opposite will happen for exponential curves. And don't forget that strength of a hit doesn't necessary have a linear effect on piezo output voltage. Curves are actually partially meant to counteract this.
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Re: The 'Gain' parameter

Postby gastric » Sun May 03, 2009 11:11 pm

What about this behaviour?

* Set GAIN = 0
* Set HighLevel = 1022
* Strike the trigger hard
* MIDI Velocity = 124
* Set GAIN = 8
* Strike the trigger hard
* MIDI Velocity = 124

I would have expected GAIN to reduce reference volage, which in turn would generate a steep input curve towards maximum velocity, in addition to causing more of my hits to reach maximum velocity (127). However, none of my hits reach maximum velocity.

Just to clarify.

* If my max pad output voltage is (arbitrarily picking this value) 4.5V
* Then if I set GAIN=0 I would expect to never be able to acheive a HighHevel of 1022 since my input V is below the reference V.
* However, if I increase GAIN=8 my input V now greatly exceeds the reference V. So I would expect to be hitting HighLevel of 1022 with nearly all of my hits regardless of velocity

Similarly, if my pad outut voltage was 2V
* Then GAIN = 0 and HighLevel = 1022 I would expect to never be able to reach maximum output of MIDI Velocity 127 since my V would never reach or exceed reference V.
* Then GAIN = 8 and HighLevel = 1022 I would expect to be able to reach maximum output of MIDI Velocity 127 with my hardest hits since output V meets reference V
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