would Medium Ultracortex fit a 58cm head? (borderline between Medium and Large)
Is there anyone else out there with a head diameter of 58cm used a medium size Mark IV headgear / does it fit?
I ask because I do not see a large Mark IV 16 channel available.
Comments
There is an intermediate size available, where 58cm is exactly in the middle of the adjustment range.
You can buy the "Print it yourself" kit here, and the frame here.
Choose "Large" from the drop down menu, which corresponds to size "M-L", midway between the OpenBCI M and L size. That will be an ideal fit for you.
Here is more info about how size is calculated:
The range is fairly forgiving though because there is 50% overlap
between sizes. This means that if you have a perfectly average head, all
three sizes would fit. Small adjusted all the way "out", Medium
adjusted to the middle of its range, and Large adjusted all the way in.
While the "range" depends on head shape, there is a specific head
size/shape for each size headset where the electrode will contact at 50% of bolt adjustment range and 50% spring compression. These are the exact numbers:
Small (-10mm from Medium)
48.9cm Circumference
17.4cm Length
13.5cm Width
8.0cm Height (from circumference line)
Medium- (average head)
55.2cm Circumference
19.3cm Length
15.5cm Width
9.0cm Height (from circumference line)
Large (+10mm from Medium)
61.5cm Circumference
21.4cm Length
17.5cm Width
10.0cm Height (from circumference line)