Hi Everyone,
I am not sure where to post this
Trying to learn and understand how You would combine two different sine waves?
And how you would be able monitor each of them visually as they go from nothing to something interact with each other ?
Is there a way to have full control over how you shape them is their a plugin or a way to go about this in your daw
I am in Logic Pro x
But I sure this can apply to any daw
I’m not sure what you intend to achieve…
Different in what way; amplitude, phase, frequency?
Combine how; mix (add), AM (multiply), FM/PM (one modulates the frequency/phase of the other)?
And if you’re shaping the source waves, they’re no longer sines. 
I think the only true additive synth in logic is alchemy
There’s a good article on using it for addictive synthesis in MusicTech website
Have a look at music tech guys YouTube vids on alchemy to get yourself familiar with alchemy 1st then read the article and just play around and experiment
If you really want to experiment try vcvrack - free modular synth - you get a lot of modules in just the free stuff including oscillators and a scope module. Warning though this is a very deep rabbit hole. You can add some paid modules ( recreations of real modules) if you get more into it.
Beginners guide here
Full free modular daw here
Tutorial to link it to logic with bridge -
I’ll see if I can any free additive soft synth plugins as well
David let me get back to You on this
But You gave me some great questions to ask myself and I thank you for that
Phil thanks I checks those out and get back here at this thread