Keyboard controllers with Sonar

MondoArt
I haven't played around too much with knobs and faders and buttons on a controller with Sonar before.  I understand how knobs can be mapped to VSTi parameters like cutoff, resonance, etc. which is cool.  Pads can be used to tap in some drum parts, again cool.  Where I get lost is in what are buttons used for?  Can they be mapped to specific functions like "undo", "metronome on/off", "rewind to start" etc?

The parameters you mention have different "nature", it is important to understand, especially in AKAI Advance case.
 
There are DAW parameters. Track volumes, mute, pan, etc. as well as DAW commands like "undo", "rewind", etc. And there are VSTi parameters  like "cutoff", "resonance", etc.
 
While from user point of view the result is "the same" (when it works), I mean you turn encoder to change "cutoff" or turn another encoder to change "pan", the way it is implemented technically is quite different.
 
There are 2 ways to control DAW (SONAR) parameters:

1. "Remote control" some parameter. Your surface should generated supported MIDI signals, which can be assign to most parameters ("Volume on track 7" for example)
2. Use SONAR Control Surface API throw some plug-in (more here http://www.azslow.com/index.php/topic,160.0.html ). Again, the surface should generated supported MIDI signals

Note that both ways work apart from "normal" MIDI use. You can use PitchBender to control volume (Mackie Control does exactly that).
 
There are also 2 ways to control VSTi parameters:

1. "MIDI" control. The signal comes the same way as notes, can be recorded into MIDI track. Some VSTis use fixed "MIDI native" signals, so PitchBend is really bending and Key velocity is used for sound loudness. In some you can configure that. The surface normally allows you to configure what it is sending, to adopt to hardware or software synth. The way it works is effectively the same.
2. VSTi Parameter Automation API. To allow automations apart from MIDI track, the API has defined how VSTi can expose its parameters for control from DAW side. Inclusive parameter names and human friendly values (so you see 1.5kHz and not just "34", MIDI values are in range 0...127). Most VSTis expose almost all parameters, other "forgot" some.

It looks like NI has introduced some additional to VSTi API for Kompete Kontrol and want convince VSTi producer implement it. I have not seen any technical details to understand why it can be better compare to what already exists.
 
"Active Controller Technology" or ACT from CW, Automap from Novation and (!) AKAI Advance (as well as all other "advanced" VSTi control solutions) use the same method (2), VSTi API.
 
So, where is the difference between these "technologies"?

• ACT is relatively buggy and CW has not touched it for (too many) years. But it is "build in" Sonar. You insert VSTi and you have it (throw some plug-in, it is a part of Sonar CS API).
• Automap has to "wrap" VSTi first. The Automation API is available for direct "host" only, so there is no other way to "intercept" it as sit between VSTi and DAW. Novation has own mapping interface, GUI and alphanumeric display on some devices (to show parameter names/values).
• Akai Advance also use "wrap". You insert Akai "VIP" wrapper, which can load other VSTis. They have color display to show the mapping and information.

Important difference between Automap and Akai Advance is in SONAR plug-in. Automap has one and so it support DAW parameters as well. There is no information (please correct me if I have overseen) AKAI is going to provide SONAR plug-in (they have not written any) and so while integration with VSTis can be good, the integration with Sonar will be at the level of cheapest DAW controller at most.
 
And finally about buttons in VSTi. If you just want "Enable"/"Disable" it, some button is the way to go
 

The Akai Advanced keyboard are not released yet, one store here in Toronto says they are getting them in May, which probably means June....
 
I guess I'll wait until I can grab one and then try it out native, then with Aszlow's plug if that doesn't work.
 
Thanks guys!

Hey Tobias
 
Wow, that's a long way from Toronto.  I've been here since I was 6 months old, and never left (for very long, anyway).
 
Yeah, I'm favouring the Akai proposition over NI for a number of reasons:
 
1) it's pricey, but still not as much $$ as the NI KK.
2) more flexible wrapper
3) screen seems nicer
 
I've tried a number of controllers from Novation, Alesis, and Nektar recently, but with none of them have I been happy with the keybed.    Of these, the Novation Impulse was the best, but felt a little too heavy for my playing style.  The Alesis was too mushy, and the Nektar too clicky and cheap-feeling, with horrid velocity curves.  Fingers crossed, the Akai has a keybed that works for me.  I fiddled with an MPK2 in the store (not plugged in) and it felt good.  They say the Advanced's are using the same keybed.  The stuff from Air might be great, but I already have Komplete 10 so maybe not for me.  A lot is going to depend on how well the VIP software works.  The previews look fantastic.

Yeah, I tried an unplugged NI in the store, and yes, it felt amazing, but since I'm looking for 61 keys, it's almost $900 here in Toronto, vs. $600 for the Akai.  Big difference, so if the Akai keys are good to play on, I'll be happy.  Still cheaper than the Novation SKii which I didn't like the keybed at all.  If the Impulse was a bit lighter to play, I'd have kept it because I was digging the Automap capability.