Additional points upon further consideration:

The only other aspect of naad not depicted in the image, according to my experience, is a subsidiary or secondary node. That is why I called my naad fragmented, but it is simply the odd case of different nodes.

That other node for me is located on the opposite side of the typical position of the principal node that is to the left, it is also higher. It has a hollow quality to it instead of the rather habitual piercing of the principal. It differs  in tonality from the principal node, and is less strident or pointillist.

It is normally to the right and forward. I perceive it slightly out of the perimeter of the psyche. But that last statement may just be an impression to be made more precise in time. Although he principle node can also be perceived similarly.

So I was advised to focus on the highest frequency some 15 years or so ago, by RishiDeva Madhvacharya. However, randomly (I think…) the secondary can become louder, and attract me more, as the principal lowers in pitch in the course of the introspection session.

I drew and posted a schematic of my naad perception per the request of RishiDeva on a previous website. I recall that he suggested that another practitioner may relate. I find it interesting that way over a decade later, the construct of my psyche has remained unchanged.

Rather, it is more specifically the perceptive state of naad is the same, whether accessed or not. Therefore, I must conclude that had I passed on by now, or when I do this is the psyche landscape that I will be working with.

Ultimately zonal naad does not provide for singular laser focusing of the attention. It is more like being in the midst of a dense forest or an englobing mist, oe being in midst of a myriad of crickets all singing in chorus. Whereas localized nodes feel more like hankering down or trying to, in a lighthouse in the middle of the ocean.

Although from the standpoint of the coreself/attention complex I experience these different naads immersively,  there are marked differences in terms of frequency, location, tonality, pitch, and even texture.