Accurately playing low notes

Been practicing theremin for about 8 weeks and am getting more comfortable around C3. I have a few questions. I am on a Moog etherwave w the pitch mod. 

I’m working a bit w Clara rockmores book. When you go beyond or below the middle octave do you take another position 1,2,3 etc on those other octaves? Or do you just move your whole arm? For instance, past C4 what do I do with my hand? It seems cumbersome to take up a new root position with my hand for that octave so I just move my arm w fingers fully extended. 

Another question. I was playing around with bass notes yesterday but the pitches were so close together - in relation to hand positions that it was difficult to play them correctly. The slightest movement threw the pitch up or down a whole tone. Is there a calibration for this so that the lower notes have the same or similar distance as the middle octave?

Thanks. 

Bass notes are a bit funky on theremins.  It sounds like your pitch field needs to be expanded. Are you keeping it tight (notes close together) so that you don't have to change hand positions?  I tune mine so that my lowest note is with my hand on my lower chest about 18 inches from the pitch antenna. I change the position of my hand for every octave.  Imagine a panel of doorknobs about 6 inches apart and you are going from one knob to the next with a slight twisting motion....that's how I do it.  Every thereminist has an individual style that works for them. Watch the experts on YouTube and try to mimic different styles until you find one that works.  After a while you will no doubt develop one that is unique to you. I hope that makes sense.

Might be worth doing a short video to show exactly where you’re struggling. 

If your piece is mostly in the very low range, try tuning so that the handspan octave is accurate closer to your body (rather than in the middle/upper range of the field). Since the field won’t be 100% linear, you’ll probably need to sacrifice the accuracy of the tuning somewhere. 

On changes in hand position, again it depends on the piece. You may need to find somewhere to change your root, either by moving your arm (‘leap of faith’), or by switching position (I find you can go from position 1 to 5 and from 8 to 1 whilst staying on the same pitch for instance). Hope that helps?

'I was playing around with bass notes yesterday but the pitches were so close together - in relation to hand positions that it was difficult to play them correctly. The slightest movement threw the pitch up or down a whole tone.' - Speedo

Something here just doesn't sit right: if anything, the bass notes should have a wider spacing than the higher notes.

Are you setting your zero beat correctly?

If so, then maybe your coils need tweaked.