Starting with the flat part to tackle an easier sketch. Using calipers to measure out parts from the broken mic holder. The spline was added for decoration, it could have just been a line. The dimensions that are shown are what I felt were important to this part, the rest are to complete the component

This is extruded with a width of 4.5mm

Using the chamfer tool to add a bevel where the mic gets slotted in and a fillet on the top edges so that there are no sharp edges. (not sure how much that helped)

I don't have the slicing software on this computer but this is the orientation of printing. This is the flattest part and doesn't really compromise the sheer forces since the mic will add some rigidity  to the lofted part and the hole will mainly have rotational forces on it. This orientation also gives the best circular shape for the mic holder and wont have drooping. When printed there wasn't a lot of supports if any? the hole on the flat part may have had support but the overall part didn't need structure because of how the angle that the flat part protruded that the layers were able to build on themselves. 

Under construct to add a new plane to start working on the part that hold the mic. I used plane at an angle and picked the edge of the part, and made the angle perpendicular to the side where the mic will be attached.  The plane is the orange square

If the mic was a cylinder the next few parts would not be necessary. This will require making two sketches and using the loft tool connect the two sketches. 

Using p to project edges of the flat piece. Two circles are made using dimensions from the old mic holder. There is a slight overlap with the flat piece to ensure that the part is printed attached together.

The plane offset is the length of the mic holder and pointed in the correct direction. As you can see that the offset is -50 mm

This sketch is dimensioned using the old mic holder. As you can see that the diameter is not the same from the bottom hole. 

Using the loft tool to create this solid. I thought I would be able to loft the ring but that wasn't the case so I went back into the sketch and did another loft of the inner circle and set the operation to cut.

Since the old part was made out of rubber so that it has more flexibility. My strain relief only requirement was to be less then half of the circle so that the mic would not fall out.  I honestly don't really remember my thought process but it really shouldn't  be this complicated. Let it have some room so that it can flex.