First off, what does proper tension look
A good way to check your tension is to stitch a
design with satin stitch columns. Hoop up a piece of quilters cotton or similar fabric
and medium weight cutaway stabilizer, adhered together with
temporary spray adhesive, and stitch out the design.
Then take a look at the back of the embroidery. If tension is good,
the bobbin thread should take up 1/3 to 1/2 of the back of a satin
stitch column (on average -- it's normal for this to vary a bit
within a design).
Thread tension isn't programmed into an
embroidery design -- it's a result of how the machine physically
handles the thread.