None of them. 1 is closest but needs to be deeper, 3 is a distant second closely followed by Sinister. 2 is totally off base, really does not feel right.
I read someone suggesting comparison to the new Lost In Space robot. Looking it up I have to agree, the tones of that robot fit the feel of Ember better than what has been presented.
Now, since there are larger omniframes as well, I can understand if maybe you want to reserve the lower register for them and this smaller one is more high pitched. If so, that needs to be made clear. But we also need to keep in mind which frame we are expected to be in most of the time.
If the primary frame is that high pitched it will get very annoying fast.
I read someone suggesting comparison to the new Lost In Space robot. Looking it up I have to agree, the tones of that robot fit the feel of Ember better than what has been presented.
Now, since there are larger omniframes as well, I can understand if maybe you want to reserve the lower register for them and this smaller one is more high pitched. If so, that needs to be made clear. But we also need to keep in mind which frame we are expected to be in most of the time.
If the primary frame is that high pitched it will get very annoying fast.