So what are in your view the main obstacles? I can image a concept based a class called "channelstrip", which as you can guess represents an audiochannelstrip handled by a channelstrip-handler. This handler also masks the jack-backend, such that the user only need to initialize it with the jack name like "TerminatorX outputs", number of threads for DSP related stuff and thats it. The handler does all the stuff from registering the jack callbacks to creating/destroying channelstrips and busses. The controlparameters of each strip are given to the user by boost::signal(2)s.

So in a nutshell the user only needs the class channelstrip and the means to create/destroy instances thereof. The concept is cleanly seperated from the other parts of the users application.

I've actually implemented this rough concept into TerminatorX and it's working. tX now has full stereo outputs of each turntable, no matter if the sample on the turntable is mono or stereo (this is missing in the current release, making it hard for many people to use tX). It should be conceptually easy to export this functuality into an external library.
Gerald
On Sat, 2011-03-26 at 13:22 -0400, Paul Davis wrote: 
On Sat, Mar 26, 2011 at 1:13 PM, Gerald Mwangi <gerald.mwangi@gmx.de> wrote:
> Hi, I'm messing arround with the source of TerminatorX. As it seems, tX
> needs a total rewright of the mixer and the audio backend.
> Since many programs (Ardour, Qtracktor) have built mixers, I was wondering
> from which project I could 'borrow' the mixer component.
> I need a mixermodel which is strictly C++, which idealy has jack support
> built in, possibly multithreaded, GUI-Independant and easy to handle.
> I started to wright my own mixermodel, but then I thought how stupid it is
> to reinvent the wheel. It would really be nice something like a libmixer
> with jack, lv2, ladspa and VST support.

i've heard people talk about this idea of an "audioengine" for years.
i've never seen it. the design inside ardour is at once both extremely
general and also very application specific. i have a hard time
imagining anything else.

--p