Earsight Stereo Mic’s Ball Setup

A few weeks ago, I bought a pair of Earsight microphones 48V XLR plugs. After testing them with the new Zoom F3, I found that, as it was logical to expect, the stereo separation with these two omnidirectional capsules was not great, despite having adopted a self-built positioning system with the capsules angled 120° and 17 cm apart from each other.
So, I decided to create a separation by inserting a 12 cm diameter sphere, made up of a ball for gymnastic postural exercises produced in Germany, the BlackRoll Ball12, whose material seems to me perfect for the project.
As a first test, being a season in which the singing of birds even during is practically nil, I tried to quickly record a few minutes of nocturnal orthoptera chorus: Oecanthus pellucens, Eupholidoptera chabrieri schmidti, Modicogryllus burdigalensis.