Attack Pressure?

Discussions about anything analog, digital, MIDI, synth technology, techniques, theories and more.
Post Reply
User avatar
madmarkmagee
Active Member
Active Member
Posts: 416
Joined: Tue Feb 15, 2011 8:18 am
Gear: King Korg
ESQ-1
Reface DX
Microbrute
Shruthi-1
Pittsburgh System-1
Juno 106 (needs work)
Location: Sydney

Attack Pressure?

Post by madmarkmagee » Tue Oct 30, 2012 1:19 pm

I know what aftertouch is (how hard you press the keys down) and velocity (How quickly you hit the keys), but reading an old SOS review of the Yamaha An1x, I've stumbled across the term "Attack pressure". The review reads: "(the keyboard has) a full 61 notes (five octaves) with aftertouch (attack pressure) sensitivity". I've stumbled across that term before and I thought that the An1x only had velocity. Is anyone familiar with the An1x? I'm very confused :?

User avatar
meatballfulton
Moderator
Moderator
Posts: 5750
Joined: Wed Apr 13, 2005 9:29 pm
Gear: Live 9, Logic Pro X

Re: Attack Pressure?

Post by meatballfulton » Tue Oct 30, 2012 2:09 pm

AN1x does have aftertouch.

The ribbon controller is also pressure sensitive.
I listened to Hatfield and the North at Rainbow. They were very wonderful and they made my heart a prisoner.

User avatar
Hybrid88
Synth Explorer
Synth Explorer
Posts: 2251
Joined: Sat Jan 17, 2009 8:26 am
Gear: V-Synth, and other stuff...
Location: Australia

Re: Attack Pressure?

Post by Hybrid88 » Tue Oct 30, 2012 5:38 pm

Wondering if it might be like a routing of the velocity to the attack time? I have a vague idea there may be something similar on the V-Synth, but I can't say I've explored it tbh

User avatar
Bitexion
Synth Explorer
Synth Explorer
Posts: 4230
Joined: Fri Apr 15, 2005 7:43 pm
Gear: Alesis Andromeda A6
Roland D-50
Creamware Minimax
Yamaha DX7s
Analogue Systems modular
Ensoniq SQ-80
Waldorf Blofeld
Location: Drammen, Norway

Re: Attack Pressure?

Post by Bitexion » Tue Oct 30, 2012 8:18 pm

Most synths with a "mod matrix" (a menu where you can set mod sources and destinations) can route velocity to envelope parameters..or any other parameter.

Rangoon
Newbie
Newbie
Posts: 65
Joined: Wed Sep 10, 2008 6:49 am
Location: Kansas City

Re: Attack Pressure?

Post by Rangoon » Wed Oct 31, 2012 12:24 am

I don't see how you can use aftertouch to effectively modulate the envelope attack. Logically, the envelope attack time has to be fully specified not later than the bottom of the keystroke because that's where the attack phase begins. Aftertouch is an event that technically occurs after that point.

User avatar
Bitexion
Synth Explorer
Synth Explorer
Posts: 4230
Joined: Fri Apr 15, 2005 7:43 pm
Gear: Alesis Andromeda A6
Roland D-50
Creamware Minimax
Yamaha DX7s
Analogue Systems modular
Ensoniq SQ-80
Waldorf Blofeld
Location: Drammen, Norway

Re: Attack Pressure?

Post by Bitexion » Wed Oct 31, 2012 2:17 am

Yeah, aftertouch is what it says. After touch. Attack pressure could mean that the attack of the sound is different depending on how hard you hit the key. It makes sense. Hit the key gently, get a slow envelope. Hit it hard, very fast envelope attack.

User avatar
madmarkmagee
Active Member
Active Member
Posts: 416
Joined: Tue Feb 15, 2011 8:18 am
Gear: King Korg
ESQ-1
Reface DX
Microbrute
Shruthi-1
Pittsburgh System-1
Juno 106 (needs work)
Location: Sydney

Re: Attack Pressure?

Post by madmarkmagee » Wed Oct 31, 2012 2:18 am

Yea the VSE review only mentions the keyboard had velocity. Thus the confusion.

I like to play acoustic piano and generally find it pretty difficult to get expression from electronic velocity sensitive keyboards. With piano I think dynamic expression is achieved mainly through how fast and how hard you initially hit the key. Obviously, once the key is down, you can't push harder to change the sound, like you can on aftertouch enabled electronic keyboards. (i don't actually have any aftertouch sensitive keyboards, so correct me if i'm wrong). Perhaps "Attack pressure", means it behaves like a piano. Any An1x owners out there? Is it any different? Do most aftertouch keyboards have a setting so it behaves like a piano?

User avatar
madmarkmagee
Active Member
Active Member
Posts: 416
Joined: Tue Feb 15, 2011 8:18 am
Gear: King Korg
ESQ-1
Reface DX
Microbrute
Shruthi-1
Pittsburgh System-1
Juno 106 (needs work)
Location: Sydney

Re: Attack Pressure?

Post by madmarkmagee » Wed Oct 31, 2012 2:20 am

Bitexion, I think you just half answered my question... XD

User avatar
Zamise
Supporting Member!
Supporting Member!
Posts: 2351
Joined: Wed Oct 20, 2004 2:41 am
Gear: Rollhand P00
Band: Quantum-Source
Location: DenverMetroUSA, Quantum-Source.com
Contact:

Re: Attack Pressure?

Post by Zamise » Wed Oct 31, 2012 4:08 pm

Yeah, they probably meant velocity sensitivity which responds to how hard you strike a key. Aftertouch is how much pressure you apply to the keys after the initial strike.

From the AN1X manual:
Channel Aftertouch
Messages which let you control the sounds by the pressure
you apply to the keys after the initial striking of the keys,
over the entire channel.
Vel Sens (Velocity Sensitivity)
The Velocity Sensitivity setting determines the amplitude
range of the VCA according to playing strength, or
how fast you strike the keys. Turning the knob to the
right (positive values) results in a higher sensitivity,
requiring greater playing strength to increase
amplitude. Turning it to the left (negative values)
requires a lighter touch to increase amplitude. A value
setting of “0” maintains the same amplitude regardless
of playing strength.
There is also a PeF Vel (lPlay Effect velocity) parameter for the arpeggiator.

There are also velocity curves:
The Keyboard Velocity parameter sets the keyboard
velocity curve which determines the way the AN1x’s
tone generator responds to keyboard playing strength...

Settings: norm, soft1, soft2, easy, wide, hard, Vel Fix (1 ~
127)
<ZQS> [....<OII>.....soundcloud player v2.42.....................link]

User avatar
cornutt
Moderator
Moderator
Posts: 2117
Joined: Sun Dec 02, 2007 6:03 am
Gear: 6th
Location: Rocket City USA
Contact:

Re: Attack Pressure?

Post by cornutt » Fri Nov 02, 2012 5:58 pm

madmarkmagee wrote: I like to play acoustic piano and generally find it pretty difficult to get expression from electronic velocity sensitive keyboards. With piano I think dynamic expression is achieved mainly through how fast and how hard you initially hit the key.
Well yeah, that was the original concept of velocity -- on a piano, how quickly you make the key go down determines how much the hammer accelerates and hence how hard it hits the string. (How hard you are pressing at the very bottom of the key stroke doesn't really matter; by that time the hammer is on its way, and the jack has uncoupled so that the hammer can rebound after it hits the string.) It's been my observation that depending on what kind of keyboard you originally learned on, you have to choose a velocity curve on the synth that works for you. Nearly all synths these days have several choices of velocity curves.

I will say that on many synths, the range of control that you have when you route velocity to a parameter is not as much as it should be, and that limits how effective velocity can be on that synth. But when you think about it, the velocity range on a piano is actually pretty extreme -- if you press the key softly enough, you get no sound at all. :mrgreen:
Do most aftertouch keyboards have a setting so it behaves like a piano?
I think the short answer to your question is to look through the synth's parameters and select an "exponential" velocity curve. Trouble is, there's no standard for doing this. On some synths, the velocity curve is a patch parameter; on others, it's a performance parameter, and on still others it's a system parameter.

The longer answer is that it's important to remember the distinction between velocity and aftertouch, and to recognize that there are different mechanisms that produce the measurements. Usually, velocity is measured by a pair of sensors attached to each key. The first sensor sends a signal to the circuitry when the key leaves the full-up position (you have just begun to press it), and the second sends a signal when the key reaches the full-down, or close to it, position. Some mechanism (often software) measures the time elapsed between these two events and computes the velocity from that. Aftertouch, on the other hand, is usually sensed by a pressure-sensitive resistor at the bottom of the key travel; when one or more keys presses on it, the aftertouch measurment changes. And remember that most synth keyboards only sense "channel" aftertouch, which means that there is one measurement value for the whole keyboard. Keyboards that produce poly aftertouch, where there is an individual pressure measurement for each key, are not very common.
Switches, knobs, buttons, LEDs, LCD screens, monitors, keys, mice, jacks, sockets. Now two joysticks!

Post Reply